Patent Publication Number: US-10778823-B2

Title: Mobile telephone and cartilage-conduction vibration source device

Description:
TECHNICAL FIELD 
     The several inventions disclosed herein relate to a mobile telephone; an incoming-talk unit or cartilage conduction vibration source for a mobile telephone or the like; a mobile telephone accessory device; a sound output device; a listening device; and an outgoing-talk/incoming-talk device. 
     BACKGROUND ART 
     Conventionally, various different mobile telephones, sound output devices, or outgoing-talk/incoming-talk devices have been proposed for various different objectives. For example, to provide a mobile telephone permitting clear listening or outgoing-talking/incoming-talking even in the presence of loud noise, there has been proposed a mobile telephone in which a bone conduction speaker is employed, the mobile telephone being provided with the bone conduction speaker as well as with external auditory meatus stoppage means (Patent Document 1). On the other hand, in another proposed method for using a bone conduction speaker, a manual operation is used to adjust the pressure of contact between the tragus and a vibrating surface to be brought into contact with the tragus, whereby the ratio at which audio information through cartilage conduction and audio information through air conduction are transmitted can be altered in accordance with the magnitude of outside noise (Patent Document 2). In yet another proposal, a piezoelectric element is used as a vibration source of bone conduction. A further proposal for an outgoing-talk/incoming-talk device for a mobile telephone is a wireless communication function headset that is wirelessly communicatively connected to a communication apparatus capable of audio communication via a communication network, the wireless communication function headset permitting audio communication with a party on the line via the communication apparatus (Patent Document 3). In yet another proposal for an outgoing-talk/incoming-talk device, an eyeglasses-type interface device is provided with an audio unit that includes a bone conduction earphone, a microphone, and a display unit for displaying, on a lens, movie information that has been sent to a wireless communication unit from a mobile telephone or the like (Patent Document 4). It is typical for a “smartphone”-type mobile telephone to be sheathed in a soft cover, as an accessory device. Various other mobile telephone accessory devices, such as headsets for wired or short-range wireless communication with a mobile telephone, have also been proposed. 
     LIST OF CITATIONS 
     Patent Literature 
     
         
         [Patent Document 1] JP-A 2003-348208 
         [Patent Document 2] JP-B 4541111 
         [Patent Document 3] JP-A 2006-86581 
         [Patent Document 4] JP-A 2005-352024 
       
    
     SUMMARY OF INVENTION 
     Technical Problem 
     However, there are numerous issues requiring further study, in relation to configurations for mobile telephones, incoming-talk units or cartilage conduction vibration sources for mobile telephones or the like, mobile telephone accessory devices, sound output devices, listening devices, and outgoing-talk/incoming-talk devices. 
     With the foregoing in view, it is an object of the several inventions disclosed herein to provide a mobile telephone, an incoming-talk unit or cartilage conduction vibration source for a mobile telephone or the like, a mobile telephone accessory device, a sound output device, a listening device, and an outgoing-talk/incoming-talk device, which are more simple in configuration. 
     Solution to Problem 
     Of the several inventions disclosed herein, the mobile telephone according to a first invention has: a mobile telephone upper side part that includes a right ear cartilage conduction unit and a left ear cartilage conduction unit which are respectively exposed at the surface of the mobile telephone surface, and a linking unit linking the right ear cartilage conduction unit and the left ear cartilage conduction unit; and a cartilage conduction vibration source for transmitting vibration to the mobile telephone upper side part. 
     In the mobile telephone according to the first invention, optionally, the cartilage conduction vibration source transmits vibration to one or the other of the right ear cartilage conduction unit and the left ear cartilage conduction unit, and the linking unit transmits the vibration to the other of the right ear cartilage conduction unit and the left ear cartilage conduction unit. 
     In the mobile telephone according to the first invention, optionally, a vibration isolating part intervenes between the mobile telephone upper side part and other sections of the mobile telephone, and the cartilage conduction vibration source is situated to the inside of the mobile telephone upper side part, in such a way as to have substantially no conduct with other sections of the mobile telephone. 
     In the mobile telephone according to the first invention, optionally, the mobile telephone upper side part is an upper frame of the mobile telephone. 
     In the mobile telephone according to the first invention, optionally, the mobile telephone upper side part is an antenna. 
     Of the several inventions disclosed herein, the mobile telephone according to a second invention has: a sound signal source unit for outputting a sound signal; an audio processing unit for applying correction to the sound signal output by the sound signal source unit, doing so on the basis of vibration transmission frequency characteristics of ear cartilage; and a cartilage conduction vibration source that is vibrated by a sound signal corrected by the audio processing part. 
     In the mobile telephone according to the second invention, optionally, the audio processing unit performs correction to boost gain on the high end in the frequency range for vibrating the cartilage conduction vibration source. 
     Of the several inventions disclosed herein, the mobile telephone according to a third invention has: a telephone function unit; a cartilage conduction unit; a cartilage conduction vibration source for vibrating the cartilage conduction unit; a power supply unit for supplying power to the cartilage conduction vibration source; and a power supply control unit for supplying power to the power supply unit, during a state in which the cartilage conduction unit is able to contact ear cartilage, and for halting the supply of power to the power supply unit, during a state in which the cartilage conduction unit does not contact ear cartilage. 
     In the mobile telephone according to the third invention, a state in which the cartilage conduction unit does not contact the ear cartilage may refer to any of a state immediately following power-up of the mobile telephone, a videoconferencing state, or a non-call state; a non-call state being brought about by a call termination signal, and a talk state being brought about by a call initiation signal. 
     The mobile telephone according to the third invention may optionally have: an amplifier for presenting a call signal to the cartilage conduction vibration source; a muting circuit inserted between the cartilage conduction vibration source and the amplifier, for muting for a predetermined time interval; and a muting control unit for initiating muting by the muting circuit, in response to the in response to the call initiation signal and the call termination signal. 
     Advantageous Effects of the Invention 
     As described above, according to the several inventions disclosed herein, there are provided a mobile telephone, an incoming-talk unit or cartilage conduction vibration source for a mobile telephone or the like, a mobile telephone accessory device, a sound output device, a listening device, and an outgoing-talk/incoming-talk device, which are more simple in configuration. 
    
    
     
       BRIEF DESCRIPTION OF DRAWINGS 
         FIG. 1  is a perspective view illustrating a first embodiment of a mobile telephone according to an aspect of the present invention (first embodiment); 
         FIGS. 2A and 2B  are side views of the first embodiment illustrating the functions of the state of right ear use and the state of left ear use; 
         FIG. 3  is a block diagram of the first embodiment; 
         FIG. 4  is a flowchart of the operation of a controller in the first embodiment of  FIG. 2 ; 
         FIG. 5  is a perspective view illustrating a second embodiment of a mobile telephone according to an aspect of the present invention (second embodiment); 
         FIG. 6  is a perspective view illustrating a third embodiment of a mobile telephone according to an aspect of the present invention (third embodiment); 
         FIG. 7  is a perspective view illustrating a fourth embodiment of a mobile telephone according to an aspect of the present invention (fourth embodiment); 
         FIG. 8  is a block diagram of the fourth embodiment; 
         FIGS. 9A and 9B  are conceptual block diagrams illustrating the elements of the configuration pertaining to an earplug bone conduction effect of the fourth embodiment; 
         FIG. 10  is a flow chart of the operation of the controller in the fourth embodiment of  FIG. 8 ; 
         FIG. 11  is a perspective view illustrating a fifth embodiment of a mobile telephone according to an aspect of the present invention (fifth embodiment); 
         FIG. 12  is a flow chart of the operation of the controller in the fifth embodiment of  FIG. 11 ; 
         FIGS. 13A, 13B and 13C  are perspective views illustrating a sixth embodiment of a mobile telephone according to an aspect of the present invention; 
         FIG. 14  is a flow chart of the operation of the controller in the sixth embodiment of  FIG. 13 ; 
         FIGS. 15A, 15B and 15C  are perspective views illustrating a seventh embodiment of a mobile telephone according to an aspect of the present invention; 
         FIG. 16  is a flow chart of the operation of the controller in the seventh embodiment of  FIG. 15 ; 
         FIGS. 17A, 17B and 17C  are perspective views illustrating an eighth embodiment of a mobile telephone according to an aspect of the present invention; 
         FIGS. 18A, 18B and 18C  are perspective views illustrating a ninth embodiment of a mobile telephone according to an aspect of the present invention; 
         FIG. 19  is a perspective view illustrating a tenth embodiment of the mobile telephone according to an aspect of the present invention (tenth embodiment); 
         FIG. 20  is a perspective view illustrating an eleventh embodiment of a mobile telephone according to an aspect of the present invention (eleventh embodiment); 
         FIGS. 21A and 21B  are side views of the eleventh embodiment illustrating the functions of the state of right ear use and the state of left ear use; 
         FIGS. 22A and 22B  are perspective views illustrating a twelfth embodiment of a mobile telephone according to an aspect of the present invention (twelfth embodiment); 
         FIG. 23  is a flow chart of the operation of the controller in the twelfth embodiment of  FIG. 22 ; 
         FIGS. 24A and 24B  are perspective views illustrating a thirteenth embodiment of a mobile telephone according to an aspect of the present invention (thirteenth embodiment); 
         FIGS. 25A and 25B  are perspective views illustrating a fourteenth embodiment of a mobile telephone according to an aspect of the present invention (fourteenth embodiment); 
         FIG. 26  is a diagram of the system of a fifteenth embodiment according to an aspect of the present invention (fifteenth embodiment); 
         FIG. 27  is a diagram of the system of a sixteenth embodiment according to an aspect of the present invention (sixteenth embodiment); 
         FIG. 28  is a block diagram of the sixteenth embodiment; 
         FIG. 29  is a block diagram of a seventeenth embodiment (seventeenth embodiment); 
         FIG. 30  is a flow chart of the operation of the controller of an incoming/outgoing-talk unit in the seventeenth embodiment of  FIG. 29 ; 
         FIG. 31  is a flow chart of the operation of the controller of the incoming/outgoing talk unit in an eighteenth embodiment (eighteenth embodiment); 
         FIG. 32  is a diagram of the system of a nineteenth embodiment according to an aspect of the present invention (nineteenth embodiment); 
         FIG. 33  is a diagram of the system of a twentieth embodiment according to an aspect of the present invention (twentieth embodiment); 
         FIG. 34  is a side view of the elements of a twenty-first embodiment according to an aspect of the present invention (twenty-first embodiment); 
         FIG. 35  is a top view of a twenty-second embodiment according to an aspect of the present invention (twenty-second embodiment); 
         FIG. 36  is a block diagram of a twenty-third embodiment according to an aspect of the present invention (twenty-third embodiment); 
         FIG. 37  is a diagram of the system of a twenty-fourth embodiment according to an aspect of the present invention (twenty-fourth embodiment); 
         FIG. 38  is block diagram of a twenty-fifth embodiment according to an aspect of the present invention (twenty-fifth embodiment); 
         FIGS. 39A and 39B  are cross-sectional views of the elements of the twenty-fifth embodiment; 
         FIG. 40  is a perspective view illustrating a modification example of the tenth embodiment in  FIG. 19 ; 
         FIG. 41  is a perspective view of a twenty-sixth embodiment according to an aspect of the present invention (twenty-sixth embodiment); 
         FIG. 42  is a block diagram of the twenty-sixth embodiment of  FIG. 41 ; 
         FIG. 43  is a flow chart relating to the operation of the controller in the twenty-sixth embodiment of  FIG. 42 , and shows step S 42  of  FIG. 10  in more detail; 
         FIGS. 44A and 44B  are a perspective view and a cross-sectional view of a twenty-eighth embodiment according to an aspect of the present invention (twenty-eighth embodiment); 
         FIGS. 45A and 45B  are cross-sectional views illustrating a first modification example and a second modification example of the twenty-eighth embodiment; 
         FIGS. 46A and 46B  are cross-sectional views of a third modification example and a fourth modification example of the twenty-eighth embodiment; 
         FIGS. 47A and 47B  are perspective views illustrating a twenty-ninth embodiment according to an aspect of the present invention, and a modification example thereof (twenty-ninth embodiment); 
         FIGS. 48A and 48B  are a perspective view and a cross-sectional view of a thirtieth embodiment according to an aspect of the present invention (thirtieth embodiment); 
         FIGS. 49A and 49B  are a longitudinal cross-sectional view and a latitudinal cross-sectional view of a thirty-first embodiment according to an aspect of the present invention (thirty-first embodiment); 
         FIGS. 50A and 50B  are cross-sectional views illustrating a first modification example and a second modification example of the thirty-first embodiment; 
         FIGS. 51A and 51B  are perspective views of a thirty-second embodiment according to an aspect of the present invention, configured as a piezoelectric bimorph element adapted for use in the mobile telephone (thirty-second embodiment); 
         FIGS. 52A and 52B  are transparent perspective views of a thirty-third embodiment according to an aspect of the present invention, and a modification example thereof (thirty-third embodiment); 
         FIGS. 53A and 53B  are external perspective views of the thirty-third embodiment and the modification example thereof; 
         FIG. 54  is a transparent perspective view of a thirty-fourth embodiment according to an aspect of the present invention (thirty-fourth embodiment); 
         FIG. 55  is a transparent perspective view relating to a thirty-fifth embodiment according to an aspect of the present invention (thirty-fifth embodiment); 
         FIGS. 56A and 56B  are transparent perspective views relating to a thirty-sixth embodiment according to an aspect of the present invention (thirty-sixth embodiment); 
         FIG. 57  is a transparent perspective view relating to a thirty-seventh embodiment according to an aspect of the present invention (thirty-seventh embodiment); 
         FIG. 58  is a cross-sectional block diagram relating a thirty-eighth embodiment according to an aspect of the present invention (thirty-eighth embodiment); 
         FIGS. 59A, 59B and 59C  are back surface transparent views and a cross-sectional view illustrating the manner in which a cartilage conduction vibration source is anchored to the mobile telephone in the thirty-eighth embodiment; 
         FIG. 60  is a flow chart of the operation of a controller  3439  in the thirty-eighth embodiment of  FIG. 58 ; 
         FIGS. 61A, 61B, 61C and 61D  are cross-sectional views of a thirty-ninth embodiment according to an aspect of the present invention, and various modification examples thereof (thirty-ninth embodiment); 
         FIGS. 62A, 62B and 62C  are cross-sectional views and a transparent perspective view of the elements of a fortieth embodiment according to an aspect of the present invention as well as various modification examples thereof (fortieth embodiment); 
         FIGS. 63A and 63B  are cross-sectional views of a forty-first embodiment according to an aspect of the present invention (forty-first embodiment); 
         FIGS. 64A, 64B, 64C and 64D  are cross-sectional views of various modification examples of the forty-first embodiment; 
         FIGS. 65A, 65B, 65C and 65D  are cross-sectional views relating to a forty-second embodiment according to an aspect of the present invention (forty-second embodiment); 
         FIGS. 66A, 66B, 66C and 66D  are cross-sectional views relating to a forty-third embodiment according to an aspect of the present invention (forty-third embodiment); 
         FIGS. 67A, 67 (B 1 ),  67 (B 2 ) and  67 (C) are cross-sectional views relating to a forty-fourth embodiment according to an aspect of the present invention (forty-fourth embodiment); 
         FIGS. 68A and 68B  are cross-sectional views relating to a forty-fifth embodiment according to an aspect of the present invention (forty-fifth embodiment); 
         FIGS. 69A, 69B and 69C  are a perspective view and cross-sectional views relating to a forty-sixth embodiment according to an aspect of the present invention (forty-sixth embodiment); 
         FIGS. 70A and 70B  are a perspective view and a cross-sectional view relating to a forty-seventh embodiment according to an aspect of the present invention (forty-seventh embodiment); 
         FIGS. 71A, 71B and 71C  are a perspective view and cross-sectional views relating to a modification example of the forty-sixth embodiment according to an aspect of the present invention; 
         FIGS. 72A, 72B, 72C, 72D and 72E  are a perspective view and cross-sectional views relating to a forty-eighth embodiment according to an aspect of the present invention (forty-eighth embodiment); 
         FIGS. 73A and 73B  are enlarged cross-sectional views of the elements of the forty-eighth embodiment and a modification example thereof; 
         FIGS. 74A, 74B, 74C, 74D and 74E  are a perspective view and cross-sectional views relating to a forty-ninth embodiment according to an aspect of the present invention, and a modification example thereof (forty-ninth embodiment); 
         FIG. 75  is a block diagram combining a partial cross-sectional view relating to a fiftieth embodiment according to an aspect of the present invention (fiftieth embodiment); 
         FIG. 76  is a block diagram combining a partial cross-sectional view relating to a fifty-first embodiment according to an aspect of the present invention (fifty-first embodiment); 
         FIG. 77  is a cross-sectional view and interior block diagram relating to a fifty-second embodiment according to an aspect of the present invention (fifty-second embodiment); 
         FIGS. 78A, 78B and 78C  are a perspective view and cross-sectional views relating to the fifty-second embodiment of  FIG. 77 ; 
         FIG. 79  is a graph illustrating an example of measurement data of the mobile telephone configured on the basis of the forty-sixth embodiment of  FIG. 69 ; 
         FIGS. 80A and 80B  are a side view and a cross-sectional view of an ear, intended to illustrate the relationship between the detailed structure of the ear and the mobile telephone of the present invention; 
         FIG. 81  is a block diagram of a fifty-third embodiment according to an aspect of the present invention (fifty-third embodiment); 
         FIG. 82  is a block diagram of a fifty-fourth embodiment according to an aspect of the present invention (fifty-fourth embodiment); 
         FIGS. 83A, 83B and 83C  are a perspective view and a-cross-sectional views of a fifty-fifth embodiment according to an aspect of the present invention (fifty-fourth embodiment); 
         FIG. 84  is a block diagram of the fifty-fifth embodiment of  FIG. 83 ; 
         FIGS. 85A and 85B  are side views intended to describe the distribution of vibration energy in a mobile telephone in the fifty-fifth embodiment of  FIG. 83 ; 
         FIGS. 86A, 86B and 86C  are a perspective view and cross-sectional views of a fifty-sixth embodiment according to an aspect of the present invention (fifty-sixth embodiment); 
         FIG. 87  is a block diagram of a fifty-seventh embodiment according to an aspect of the present invention (fifty-seventh embodiment); 
         FIGS. 88A, 88B and 88C  are a perspective view and a-cross-sectional views of a fifty-eight embodiment according to an aspect of the present invention (fifty-eight embodiment); 
         FIGS. 89A, 89B and 89C  are a perspective view and a-cross-sectional views of a fifty-ninth embodiment according to an aspect of the present invention (fifty-ninth embodiment); 
         FIGS. 90A, 90B and 90C  are a perspective view and cross-sectional views of a sixtieth embodiment according to an aspect of the present invention (sixtieth embodiment); 
         FIGS. 91A, 91B and 91C  are a perspective view and cross-sectional views of a sixty-first embodiment according to an aspect of the present invention (sixty-first embodiment); 
         FIGS. 92A, 92B and 92C  are perspective views and a side view of a sixty-second embodiment according to an aspect of the present invention (sixty-second embodiment); 
         FIG. 93  is a block diagram of the sixty-second embodiment of  FIG. 93 ; 
         FIGS. 94A, 94B, 94C and 94D  are side cross sectional views of cordless handsets in the sixty-second embodiment of  FIG. 92  and modification examples thereof; 
         FIGS. 95A, 95B and 95C  are cross sectional views of a sixty-third embodiment according to an aspect of the present invention (sixty-third embodiment); 
         FIGS. 96A, 96B, 96C and 96D  are a perspective view, cross sectional views, and a top view of a sixty-fourth embodiment according to an aspect of the present invention (sixty-fourth embodiment); 
         FIGS. 97A, 97B, 97C and 97D  are a perspective view, cross sectional views, and a top view of a sixty-fifth embodiment according to an aspect of the present invention (sixty-fifth embodiment); 
         FIGS. 98A, 98B, 98C and 98D  are a perspective view, cross sectional views, and a top view of a sixty-sixth embodiment according to an aspect of the present invention (sixty-sixth embodiment); 
         FIGS. 99A, 99B and 99C  are a perspective view and cross sectional views of a sixty-seventh embodiment according to an aspect of the present invention (sixty-seventh embodiment); 
         FIG. 100  is a cross sectional view of a sixty-eighth embodiment according to an aspect of the present invention (sixty-eighth embodiment); 
         FIGS. 101A, 101B and 101C  are a system configuration diagram and usage description diagrams of a sixty-ninth embodiment according to an aspect of the present invention (sixty-ninth embodiment); 
         FIG. 102  is a block diagram of the sixty-ninth embodiment; 
         FIGS. 103A and 103B  are perspective views of a seventieth embodiment according to an aspect of the present invention (seventieth embodiment); 
         FIG. 104  is a block diagram of the seventieth embodiment; 
         FIGS. 105A, 105B and 105C  are perspective views and a cross sectional view of a seventy-first embodiment according to an aspect of the present invention (seventy-first embodiment); 
         FIG. 106  is a block diagram of the seventy-first embodiment; 
         FIG. 107  is a block diagram relating to a seventy-second embodiment according to an aspect of the present invention (seventy-second embodiment); 
         FIGS. 108A and 108B  are timing charts of power supply control to a charge pump circuit in the seventy-second embodiment; 
         FIG. 109  is flowchart of operation of an application processor in the seventy-second embodiment; 
         FIGS. 110A, 110B, 110C and 110D  are perspective views relating to a seventy-third embodiment according to an aspect of the present invention (seventy-third embodiment); 
         FIGS. 111A, 111B and 111C  are perspective views showing several video phone modes in the seventy-third embodiment; 
         FIG. 112  is a flowchart showing videoconferencing processing in the seventy-third embodiment; 
         FIG. 113  is a flowchart showing the details of Step S 376  of  FIG. 112 ; 
         FIG. 114  is a block diagram relating to a seventy-fourth embodiment according to an aspect of the present invention (seventy-fourth embodiment) 
         FIG. 115  is a block diagram relating to a seventy-fifth embodiment according to an aspect of the present invention (seventy-fifth embodiment); 
         FIG. 116  is a block diagram relating to a seventy-sixth embodiment according to an aspect of the present invention (seventy-sixth embodiment); 
         FIG. 117  is a block diagram relating to a seventy-seventh embodiment according to an aspect of the present invention (seventy-seventh embodiment); 
         FIGS. 118A and 118B  are cross sectional views of a front surface and a side surface relating to a seventy-eighth embodiment according to an aspect of the present invention (seventy-eighth embodiment); 
         FIGS. 119A and 119B  are cross sectional views of a front surface and a side surface relating to a seventy-ninth embodiment according to an aspect of the present invention (seventy-ninth embodiment); 
         FIGS. 120A and 120B  are cross sectional views of a front surface and a side surface relating to an eightieth embodiment according to an aspect of the present invention (eightieth embodiment); 
         FIGS. 121A, 121B and 121C  are cross sectional views of a side surface relating to an eighty-first embodiment according to an aspect of the present invention, and a first modification example and second modification example thereof (eighty-first embodiment); 
         FIG. 122  is a block diagram relating to an eighty-second embodiment according to an aspect of the present invention (eighty-second embodiment); 
         FIG. 123  is a flowchart of an application processor in the eighty-second embodiment of  FIG. 122 ; 
         FIGS. 124A and 124B  are perspective views relating to an eighty-third embodiment according to an aspect of the present invention (eighty-third embodiment); 
         FIG. 125  is a perspective view showing a modification example of the eighty-third embodiment of  FIG. 124 ; 
         FIGS. 126A, 126B and 126C  are a perspective view and cross sectional views relating to an eighty-fourth embodiment according to an aspect of the present invention (eighty-fourth embodiment); 
         FIG. 127  is a block diagram of the eighty-fourth embodiment of  FIG. 126 ; 
         FIGS. 128A, 128B and 128C  depict cross sectional views of a modification example of the eighty-fourth embodiment of  FIG. 126 ; 
         FIG. 129  is a block diagram of a modification example of the eighty-fourth embodiment of  FIG. 128 ; 
         FIGS. 130A, 130B and 130C  are a perspective view and a cross sectional view relating to an eighty-fifth embodiment according to an aspect of the present invention and a modification example thereof (eighty-fifth embodiment); 
         FIG. 131  is a block diagram relating to an eighty-sixth embodiment of the present invention (eighty-sixth embodiment); 
         FIGS. 132A, 132B and 132C  depict graphs relating to the eighty-sixth embodiment of  FIG. 131 , which show image depictions of frequency characteristics of a piezoelectric bimorph element, of ear cartilage, and of the drive output to the piezoelectric bimorph element; 
         FIG. 133  is a flowchart of a controller in the eighty-sixth embodiment of  FIG. 131 ; 
         FIGS. 134A and 134B  depict perspective views showing a modification example of the eighty-sixth embodiment of  FIG. 131 ; 
         FIG. 135  is a block diagram relating to an eighty-seventh embodiment of the present invention (eighty-seventh embodiment); 
         FIGS. 136A, 136B, 136C, 136D and 136E  are a perspective view and cross sectional views relating to an eighty-eighth embodiment of the present invention (eighty-eighth embodiment); 
         FIGS. 137A and 137B  are side views describing a call condition in the eighty-eighth embodiment of  FIG. 136 ; 
         FIGS. 138A, 138B, 138C and 138D  depict cross sectional views showing modification examples of the eighty-eighth embodiment of  FIG. 136 ; 
         FIGS. 139A and 139B  are system configuration diagrams of an eighty-ninth embodiment of the present invention (eighty-ninth embodiment); 
         FIGS. 140A and 140B  are system configuration diagrams of a ninetieth embodiment of the present invention (ninetieth embodiment); 
         FIGS. 141A, 141B and 141C  are cross sectional views and block diagrams relating to a ninety-first embodiment of the present invention (ninety-first embodiment); 
         FIGS. 142A and 142B  are system configuration diagrams of a ninety-second embodiment of the present invention (ninety-second embodiment); 
         FIGS. 143A, 143B and 143C  depict side views of an ear, for showing a modification example of the ninety-second embodiment; 
         FIGS. 144A and 144B  are a back view and a block diagram of a ninety-third embodiment of the present invention (ninety-third embodiment); 
         FIGS. 145A and 145B  are a back cross sectional view and a block diagram of a ninety-fourth embodiment of the present invention (ninety-fourth embodiment); and 
         FIG. 146  is a block diagram of a ninety-fifth embodiment of the present invention (ninety-fifth embodiment). 
     
    
    
     SOLUTION TO PROBLEM 
     First Embodiment 
       FIG. 1  is a perspective view illustrating a first embodiment of the mobile telephone according to an aspect of the present invention. In  FIG. 1 , a mobile telephone  1  comprises an upper part  7  having a display unit  5  or the like, and a lower part  11  having a keypad or other operation unit  9  and a microphone or other outgoing-talk unit  23  for picking up audio uttered from the mouth of an operator, and is configured such that the upper part  7  can be folded onto the lower part  11  by a hinge unit  3 . An earphone or other incoming-talk unit  13  for transmitting audio to an ear of the operator is provided to the upper unit  7 , and together with the outgoing-talk unit  23  of the lower part  11  constitutes a telephone function unit. A videoconferencing in-camera  17 , which is able to photograph the face of an operator looking at the display unit  5  in a case in which the mobile telephone  1  is to be used as a video phone and which is also used when a self-portrait is taken, is also arranged on the upper part  7 . The upper part  7  is further provided with a pair of infrared light emitting units  19 ,  20  constituting a proximity sensor for detecting that the mobile telephone  1  is abutting an ear for purposes of a call, and with a shared infrared light proximity sensor  21  for receiving infrared light reflected from the ear. Although not shown in  FIG. 1 , a backside camera is provided to the backside of the upper part  7 , and the camera is able to capture an image of a subject that is on the backside of the mobile telephone  1  and is being monitored with the display unit  5 . 
     The upper part  7  is further provided with a right-ear cartilage-conduction vibration unit  24  and a left-ear cartilage-conduction vibration unit  26 , which comprise a piezoelectric bimorph element or the like for contacting the tragus, at the upper corner of the inside (the side that touches the ear). The right-ear cartilage-conduction vibration unit  24  and the left-ear cartilage-conduction vibration unit  26  are constituted so as not to protrude from the outer wall of the mobile telephone and hinder the design, but are provided to the corners of the outer wall of the mobile telephone whereby contact is effectively made with the tragus. It is thereby possible both to listen to the audio from the incoming-talk unit  13 , and to listen by bone conduction from the cartilage of the tragus. Also, as has been disclosed in the above-mentioned Patent Document 2, the tragus is known to receive the greatest auditory sensation among the mastoid process of the ear, the cartilage surface of the rear of the opening of the outer ear, the tragus, the sideburn part, and all the other constituents of the ear cartilage; and is known to have a greater elevation in the bass register than other locations when pressure is increased by pushing. This knowledge is described in detail in Patent Document 2, for which reference can accordingly be made thereto. 
     The mobile telephone  1  rotates slightly clockwise when brought up against the right ear in  FIG. 1 , and takes on a downward-right state in  FIG. 1 . Providing the right-ear cartilage-conduction vibration unit  24  to the lower angle of incline of the upper end of the ear side of such a mobile telephone makes it possible to naturally bring the right-ear cartilage-conduction vibration unit  24  in contact with the tragus of the right ear without causing the vibration unit to protrude from the outer wall of the mobile telephone. This state is a posture approximating the normal state of a telephone call, and is awkward for neither the person making the telephone call nor any onlookers. Because the incoming-talk unit  13  is in the vicinity of the right-ear cartilage-conduction vibration unit  24 , audio information through the tragus cartilage and audio information through the external auditory meatus will both be transmitted to the ear. At this time, because the same audio information will be transmitted by different sound-generating pairs and pathways, the phasing between the two is adjusted so as to prevent the same from canceling each other out. 
     On the other hand, the mobile telephone  1  rotates slightly counter-clockwise when brought up against the left ear in  FIG. 1 , and takes on a downward-left state in  FIG. 1 . The state becoming such that the left-ear cartilage-conduction vibration unit  26  is provided to the lower angle of incline of the upper end of the ear side of the mobile telephone, it is possible to naturally bring the left-ear cartilage-conduction vibration unit  26  into contact with the tragus of the left ear, as is the case with the right ear. Because this state is a posture approximating the normal state of a telephone call, and because the incoming-talk unit  13  is in the vicinity of the left-ear cartilage-conduction vibration unit  26  and both audio information through the tragus cartilage and audio information through the external auditory meatus are transmitted to the ear, the fact that the phasing between the two is adjusted is similar to the case of the right ear. 
     Because the pair of infrared light emitting units  19 ,  20  in the above-described proximity sensor emit light alternating in time division, the shared infrared light proximity sensor  21  is able to identify from which light-emitting unit the reflective light coming from the infrared light has been received, and is thereby able to judge which of the right-ear cartilage-conduction vibration unit  24  and the left-ear cartilage-conduction vibration unit  26  has been brought up against the tragus. It is thereby possible to determine at which ear the mobile telephone  1  is being used, and to cause the vibration unit of the side against which the tragus abuts to vibrate and to turn off the other one. However, because of the individual variations regarding up to which ear the mobile telephone  1  is brought and regarding the shape of the ear, the first embodiment is configured such that, as will be described later, an acceleration sensor is further housed, the direction in which the mobile telephone  1  is inclined being detected by the gravitational acceleration detected by the acceleration sensor, and the vibration unit on the side at the lower angle of incline is made to vibrate while the other is turned off. The aforementioned right ear use and left ear use will again be described, using the drawings adapted to the respective modes of use. 
     The upper part  7  is further provided with an environment-noise microphone  38 , which is arranged on the outside (the back surface not brought up against the ear) so as to pick up environment noise, and which is implemented as means for preventing conduction of the vibration of the right-ear cartilage-conduction vibration unit  24  and the left-ear cartilage-conduction vibration unit  26 . The environment-noise microphone  38  further picks up audio uttered from the mouth of the operator. The environment noise picked up by the environment-noise microphone  38  and the operator&#39;s own voice, upon undergoing wavelength inversion, are mixed into the right-ear cartilage-conduction vibration unit  24  and the left-ear cartilage-conduction vibration unit  26 ; the environment noise and the operator&#39;s own voice, which are contained in the audio information through the incoming-talk unit  13 , are canceled to facilitate listening comprehension of the party on the line. A more detailed description of this function will be provided later. 
       FIG. 2  is a side view of the mobile telephone  1  illustrating the functions of the right-ear cartilage-conduction vibration unit  24  and left-ear cartilage-conduction vibration unit  26 ;  FIG. 2A  illustrates a state in which the mobile telephone  1  is held in the right hand and brought up against the right ear  28 . On the other hand,  FIG. 2B  illustrates a state in which the mobile telephone  1  is held in the left hand and brought up against the left ear  30 .  FIG. 2A  is a drawing viewed from the right side of the face, and  FIG. 2B  is a drawing viewed from the left side of the face; therefore, each show the back surface of the mobile telephone  1  (the reverse side of  FIG. 1 ). The mobile telephone  1  is indicated by dashed lines, in order to depict the relationship between the mobile telephone  1  and the right ear  28  and left ear  30 . 
     As illustrated in  FIG. 2A , the mobile telephone  1  is inclined slightly counterclockwise (the relationship of the reverse surface with  FIG. 1 ) in  FIG. 2  when the same is brought up against the right ear  28 , and takes on a diagonally downward-left state in  FIG. 2 . Because the right-ear cartilage-conduction vibration unit  24  is provided to the lower angle of incline of the upper end of the ear side of such a mobile telephone, the same can naturally be brought into contact with the tragus  32  of the right ear  28 . As has already been described, this state is a posture approximating the normal state of a telephone call, and is awkward neither to the person making the telephone call nor to onlookers. On the other hand, as illustrated in  FIG. 2B , the mobile telephone  1  is inclined slightly clockwise (the relationship of the reverse side with  FIG. 1 ) in  FIG. 2  when the same is brought up against the left ear  30 , and takes on a diagonally downward-right state in  FIG. 2 . Because the left-ear cartilage-conduction vibration unit  26  is provided to the lower angle of incline of the upper end of the ear side of such a mobile telephone, the same can naturally be brought into contact with the tragus  34  of the left ear  30 . This state as well, as is the case with the right ear  28 , is a posture approximating the normal state of a telephone call, and is awkward neither to the person making the telephone call nor to onlookers. 
       FIG. 3  is a block diagram of the first embodiment, the same portions being given the same reference numerals as in  FIG. 1 , and a description having been omitted unless necessary. The mobile telephone  1  is controlled by a controller  39 , which operates in accordance with a program stored in a memory unit  37 . The memory unit  37  is further able to temporarily store data needed for the control of the controller  39  and also to store various measurement data and/or images. The display unit  5  displays on the basis of the control of the controller  39  and on the basis of display data held by a display driver  41 . The display unit  5  has a display backlight  43 , the controller  39  adjusting the brightness thereof on the basis of the brightness of the surroundings. 
     A telephone function unit  45 , which includes the incoming-talk unit  13  and the outgoing-talk unit  23 , is capable of connecting with a wireless telephone line using a telephone communication unit  47 , which is under the control of the controller  39 . A speaker  51  provides ring alerts and various types of guidance by the control of the controller  39 , and also outputs the other party&#39;s voice during a videoconferencing function. The audio output of the speaker  51  is not to be outputted from the right-ear cartilage-conduction vibration unit  24  and the left-ear cartilage-conduction vibration unit  26 , because it is not possible to bring a cartilage conduction vibration unit up against the ear during a videoconferencing function. An image processing unit  53  is controlled with the controller  39  and processes an image photographed by a videoconferencing function in-camera  17  and a backside main camera  55 , and inputs the image resulting from the processing into the memory unit  37 . 
     As described above, the pair of infrared light emitting units  19 ,  20  in the proximity sensor emit light alternating in time division on the basis of the control of the controller  39 . Accordingly, the reflected infrared light inputted into the controller  39  by the shared infrared light proximity sensor  21  allows for identification of reflected light by the infrared light from either light-emitting unit. When reflected light is detected from both the infrared light emitting units  19 ,  20 , the controller  39  runs a cross comparison to determine which of the right-ear cartilage-conduction vibration unit  24  and left-ear cartilage-conduction vibration unit  26  has been brought up against the tragus. Further, the acceleration sensor  49  detects the orientation of the detected gravitational acceleration. The controller  39  determines, on the basis of the detection signal, whether the mobile telephone  1  is inclined in the state of  FIG. 2A  or  FIG. 2B ; as has been described with  FIG. 2 , the vibration unit on the side at the lower angle of incline is made to vibrate and the other is turned off. 
     The mobile telephone  1  further possesses a phase adjustment mixer unit  36  for running phase adjustment for the audio information from the controller  39  and for transmitting to the right-ear cartilage-conduction vibration unit  24  and left-ear cartilage-conduction vibration unit  26 . More specifically, the phase adjustment mixer unit  36  uses the audio information transmitted to the incoming-talk unit  13  from the controller  39  as a benchmark to run phase adjustment for the audio information from the controller  39  and transmits to the right-ear cartilage-conduction vibration unit  24  and left-ear cartilage-conduction vibration unit  26 , in order to prevent the mutual canceling out of the audio information generated from the incoming-talk unit  13  and transmitted via the tympanic membrane from the external auditory meatus and of the same audio information generated from either the right-ear cartilage-conduction vibration unit  24  or left-ear cartilage-conduction vibration unit  26  and transmitted via the cartilage of the tragus. The phase adjustment is a relative adjustment between the incoming-talk unit  13  and the right-ear cartilage-conduction vibration unit  24  and left-ear cartilage-conduction vibration unit  26 , and therefore the configuration may be such that the audio information transmitted from the controller  39  to the right-ear cartilage-conduction vibration unit  24  and left-ear cartilage-conduction vibration unit  26  is used as a benchmark for adjusting the phase of the audio information transmitted from the controller  39  to the incoming-talk unit  13 . In this case, the audio information to the speaker  51  is also adjusted in the same phase as the audio information to the incoming-talk unit  13 . 
     In addition to having the first function described above of preventing the mutual canceling out of the audio information from the incoming-talk unit  13  and the identical audio information from the right-ear cartilage-conduction vibration unit  24  or the left-ear cartilage-conduction vibration unit  26 , the phase adjustment mixer unit  36  also has a second function through collaboration with the environment-noise microphone  38 . In this second function, the environment noise picked up by the environment-noise microphone  38  and the operator&#39;s own voice, upon undergoing wavelength inversion by the phase adjustment mixer unit  36 , are mixed into the audio information of the right-ear cartilage-conduction vibration unit  24  or the left-ear cartilage-conduction vibration unit  26 ; the environment noise and the operator&#39;s own voice, which are contained in the audio information through the incoming-talk unit  13 , are thereby canceled to facilitate listening comprehension of the audio information of the party on the line. At this time, the mixing is done also taking into consideration the phase adjustment that is based on the first function, so as to effectively cancel out the environment noise and the operator&#39;s own voice regardless of the different transmission routes of the audio information from the incoming-talk unit  13  and the audio information from either the right-ear cartilage-conduction vibration unit  24  or the left-ear cartilage-conduction vibration unit  26 . 
       FIG. 4  is a flowchart of the operation of the controller  39  in the first embodiment of  FIG. 2 . To provide a description primarily of the function of the right-ear cartilage-conduction vibration unit  24  and the left-ear cartilage-conduction vibration unit  26 , the flow of  FIG. 4  illustrates an abstraction of the operation, focusing on related functions; the controller  39  also contains typical mobile telephone functions and other operations not represented in the flow of  FIG. 4 . The flow of  FIG. 4  begins when a main power source is turned on by the operation unit  9  of the mobile telephone  1 ; and in step S 2  an initial startup and a check of each unit function are performed and a screen display on the display unit  5  is started. Next, in step S 4 , the functions of the right-ear cartilage-conduction vibration unit  24  and left-ear cartilage-conduction vibration unit  26  are turned on to proceed on to step S 6 . Step S 6  is a check of the presence or absence of an e-mail operation and/or Internet operation, as well as other operations in which radio operations are not used, such as various settings and also downloaded games (which hereinafter are collectively referred as “non-call operations”). In the case of these operations, execution proceeds on to step S 8  for non-call processing, and then arrives at step S 10 . However, the function in non-call operations is not assumed to be a function of the incoming-talk unit  13  and/or the right-ear cartilage-conduction vibration unit  24  and left-ear cartilage-conduction vibration unit  26  in the upper part  7  of the mobile telephone  1  that is performed brought up against the ear. On the other hand, step S 6  proceeds directly on to step S 10  when no non-call operations are detected. 
     In step S 10 , there is performed a check for whether or not there is an incoming call by mobile radio waves. A case of no incoming call proceeds on to step S 12 ; there is performed a check for whether or not there has been a response from the other party to a call request from the mobile telephone  1 . A case in which a response is detected proceeds on to step S 14 . On the other hand, a case in which it is detected by mobile radio waves in step S 10  that there is an incoming call moves on to step S 16 , in which there is performed a check for whether the mobile telephone  1  is open; i.e., a check for whether the upper part  7  has gone from a state of being folded over the lower part  11  to an opened state as in  FIG. 1 . A case in which it is not possible to detect that the mobile telephone  1  is open returns to step S 10 ; thereafter, step S 10  and step S 16  are repeated and the flow pauses for the mobile telephone  1  to be open. However, when, during this repetition, the incoming call is terminated while the mobile telephone  1  remains unopened, the flow moves from step S 10  to step S 12 . On the other hand, a case in which it has been detected in step S 16  that the mobile telephone  1  is open proceeds to step S 14 . In step S 14 , the outgoing-talk unit  23  and the incoming-talk unit  13  are turned on to move on to step S 18 . In step S 18 , there is a check whether or not the call is a videoconferencing function, the flow moving on to step S 20  when the call is not a videoconferencing function; at this point in time, there is a confirmation of whether or not the call is cut off, the flow moving on to step S 22  when the call is not cut off. 
     In step S 22 , there is performed a check for whether or not the infrared light proximity sensor  21  detects contact with an ear, and the flow proceeds to step S 24  when no contact is detected. On the other hand, in step S 22  the flow returns to step S 14  when the infrared light proximity sensor  21  does not detect contact with an ear; as follows, step S 14  and from step S 18  to S 22  are repeated and detection by the proximity sensor in step S 22  is awaited. In step S 24 , there is performed a check for whether an incline of the right ear call state has occurred as illustrated in  FIG. 2A , on the basis of the detection signal of the acceleration sensor  49 . In a case in which this is true, the flow proceeds to step S 26 ; the right-ear cartilage-conduction vibration unit  24  is turned on, and the flow moves on to step S 28 . On the other hand, in a case in which it cannot be detected in step S 24  that the incline of the right ear call state has occurred, the flow proceeds on to step S 30  after the detection signal of the acceleration sensor  49  signifies that the left ear call state as illustrated in  FIG. 2B  has been detected; the left-ear cartilage-conduction vibration unit  26  is turned on, and the flow moves on to step S 28 . 
     In the above description of  FIG. 4 , the flow is described as proceeding on to step S 24  regardless of whether the infrared reflected light detected by the infrared light proximity sensor  21  comes from the infrared light emitting unit  19  or  20 , and in step S 24  the signal of the acceleration sensor  49  is used to detect whether or not the incline is in the right ear call state. However, because the infrared light proximity sensor  21  can also be used to detect whether or not the incline is in the right ear call state, the configuration may be such that, instead of the signal of the acceleration sensor  49  in step S 24 , the incline is judged to be in the right ear call state when the output of the infrared light proximity sensor  21  in the light-emitting timing of the infrared light emitting unit  19  is greater than that in the light-emitting timing of the infrared light emitting unit  20 . Also, the configuration in step S 24  may be such that the judgment of whether or not the incline is in the right ear call state is made together with the signal of the acceleration sensor  49  and the results of a comparison of the outputs of the infrared light proximity sensor  21  in the light-emitting timings of the infrared light emitting units  19 ,  20 . 
     In step S 28 , there is performed a check for whether or not the call state has been cut off, the flow returning to step S 24  when the call has not been cut off; as follows, step S 24  to step S 30  are repeated until a call interruption is detected in step S 28 . Support is thereby provided for switching the hand holding the mobile telephone  1  during a call, between the right ear call state and the left ear call state. On the other hand, in a case in which a call interruption is detected in step S 28 , the flow moves on to step S 32 , in which either the right-ear cartilage-conduction vibration unit  24  or the left-ear cartilage-conduction vibration unit  26  that is in an on state, as well as the incoming-talk unit  13  and the outgoing-talk unit  23 , are turned on, and the flow then moves on to step S 34 . On the other hand, in a case in which a call request response has been detected in step S 12 , the flow moves directly on to step S 34 . In a case in which there is detected to be a videoconferencing function in step S 18 , the flow moves on to the videoconferencing function processing of step S 36 . The videoconferencing function processing involves imaging one&#39;s face using the videoconferencing function in-camera  17 , outputting the voice of the other party using the speaker  51 , switching the sensitivity of the outgoing-talk unit  23 , displaying the face of the other party on the display unit  5 , or the like. Once such videoconferencing function processing has concluded, the flow proceeds to step S 38 , which turns off the speaker  51 , the incoming-talk unit  13 , and the outgoing-talk unit  23 , whereupon the flow moves on to step S 34 . In a case in which a call interruption is detected in step S 20 , the flow also moves on to step S 38 , but since the speaker  51  is not originally turned on at that time, the incoming-talk unit  13  and the outgoing-talk unit  23  are turned off and the flow moves on to step S 34 . 
     In step S 34 , there is a check for the presence or absence of an operation to turn off the primary power source; the flow is terminated when there is a turning-off operation. On the other hand, when there is no detection of an operation to turn off the primary power source in step S 34 , the flow returns to step S 6 , whereupon steps S 6  to step S 38  are repeated. As described above, the right-ear cartilage-conduction vibration unit  24  or the left-ear cartilage-conduction vibration unit  26  will not be turned on when the mobile telephone  1  is not open, when the mobile telephone  1  is not in the call state, when the call state is enabled but is a videoconferencing function, or when an ordinary call state is enabled but the mobile telephone  1  is not brought up against the ear. Once the right-ear cartilage-conduction vibration unit  24  or the left-ear cartilage-conduction vibration unit  26  is in the on state, then as long as a call interruption is not detected, it will not be turned off except when on/off switching of the right-ear cartilage-conduction vibration unit  24  or the left-ear cartilage-conduction vibration unit  26  is performed. 
     Second Embodiment 
       FIG. 5  is a perspective view depicting a second embodiment of the mobile telephone according to an aspect of the present invention. Structurally there is much in common in the second embodiment, and so corresponding portions have been given like reference numerals as in the first embodiment, and a description has been omitted. The mobile telephone  101  of the second embodiment has an integrated type with no movable parts, rather than a folding one separated into an upper part and a bottom part. Accordingly, the “upper part” in such a case does not signify a separated upper part but rather signifies the portion at the top of the integrated structure. 
     In the second embodiment, the right-ear cartilage-conduction vibration unit  24  and the left-ear cartilage-conduction vibration unit  26  assume a form of being constantly exposed on the outer wall of the mobile telephone  101 , whereas in the first embodiment, the right-ear cartilage-conduction vibration unit  24  and the left-ear cartilage-conduction vibration unit  26  assume a form of being housed while sandwiched between the upper part  7  and the lower part  11  when the mobile telephone  1  is folded shut. The essential points of the internal structure of  FIG. 3  and the flowchart of  FIG. 4  can be applied to the second embodiment as well. Regarding the above-described structural differences, step S 16  of the flowchart of  FIG. 4  is left out; in a case in which an incoming telephone call is confirmed in step S 10 , the flow moves directly on to step S 14 . 
     Third Embodiment 
       FIG. 6  is a perspective view illustrating a third embodiment of the mobile telephone according to an aspect of the present invention. Structurally there is much in common in the third embodiment, and so corresponding portions have been given like reference numerals as in the first embodiment, and a description has been omitted. The mobile telephone  201  of the third embodiment has a structure in which the upper part  107  is able to slide relative to the lower part  111 . In the structure of the third embodiment, the up-down relationship is lost in the state in which the upper part  107  is placed on top of the lower part  111 , but the “upper part” in the third embodiment signifies the portion that comes up when the mobile telephone  201  is extended. 
     In the third embodiment, full functionality is available in the state in which, as illustrated in  FIG. 6 , the upper part  107  is extended to expose the operation unit  9 , and also basic functionality, such as responding to incoming calls and/or participating in a call, is also available in a case in which the upper part  107  is placed on top of the lower part  111  and the operation unit  9  is concealed. In the third embodiment as well, the right-ear cartilage-conduction vibration unit  24  and the left-ear cartilage-conduction vibration unit  26  assume a form of being constantly exposed on the outer wall of the mobile telephone  201  in both the state in which, as illustrated in  FIG. 6 , the mobile telephone  201  is extended, and the state in which the upper part  107  is placed on top of the lower part  111 . The essential points of the internal structure of  FIG. 3  and the flowchart of  FIG. 4  can be applied to the third embodiment as well. However, as described above, the third embodiment allows calls to take place even when the upper part  107  is placed on top of the lower part  111 , and therefore, similarly with respect to the second embodiment, step S 16  of the flowchart in  FIG. 4  is left out; in a case in which an incoming call is confirmed in step S 10  the flow moves directly on to step S 14 . 
     The implementation of the variety of features of the present invention as described above is not to be limited to the above embodiments; they can be implemented in other aspects as well. For example, because the above embodiments support both right ear usage and left ear usage from changing hands and/or changing users, although the right-ear cartilage-conduction vibration unit  24  and the left-ear cartilage-conduction vibration unit  26  have been provided, the cartilage conduction vibration unit may be singular in a case that assumes usage of only the right ear or of only the left ear for cartilage conduction. 
     Also, although the right-ear cartilage-conduction vibration unit  24  and the left-ear cartilage-conduction vibration unit  26  have originally been provided with the assumption that each would abut the tragus of the right ear and the tragus of the left ear, respectively, cartilage conduction is also possible in an ear cartilage constituent other than the tragus, such as the mastoid process or the cartilage surface of the rear of the opening of the outer ear, as has been disclosed in Patent Document 2; therefore, both the right-ear cartilage-conduction vibration unit  24  and the left-ear cartilage-conduction vibration unit  26  may be used when, for example, the right ear is used, by simultaneously pushing against appropriate points on the right ear cartilage. In this sense, the two cartilage conduction vibration units  24 ,  26  need not be limited to right ear usage and left ear usage. Both are turned on at the same time in such a case, instead of only turning on either one of the two cartilage conduction vibration units  24 ,  26 , as in the embodiments. 
     Further, although the incoming-talk unit  13  and the right-ear cartilage-conduction vibration unit  24  and left-ear cartilage-conduction vibration unit  26  are to be turned on at the same time in the embodiments above, the configuration may be such that the incoming-talk unit  13  is to be turned off when either the right-ear cartilage-conduction vibration unit  24  or the left ear cartilage conduction unit  26  is turned on. In such a case, there is no longer a need for phase adjustment of the audio information. 
     Fourth Embodiment 
       FIG. 7  is a perspective view illustrating a fourth embodiment of the mobile telephone according to an aspect of the present invention. Structurally there is much in common in the fourth embodiment; therefore, corresponding portions have been given like reference numerals as in the first embodiment, and a description has been omitted. A mobile telephone  301  of the fourth embodiment has an integrated type with no movable parts, rather than a folding one separated into an upper part and a bottom part, similarly with respect to the second embodiment. Also, this embodiment is configured as a “smartphone,” which has a large-screen display unit  205  provided with graphical user interface (GUI) functionality. In the fourth embodiment as well, “upper part” does not signify a separated upper part but rather signifies the portion at the top of the integrated structure. However, in the fourth embodiment, a keypad or other operation unit  209  is displayed on the large-screen display unit  205 , and the GUI is operated in accordance with how a finger is touched and/or swiped relative to the large-screen display unit  205 . 
     The cartilage conduction vibration functionality in the fourth embodiment is assigned to a cartilage conduction vibration unit, which has a vibration conductor  227  and a cartilage conduction vibration source  225 , comprising a piezoelectric bimorph or the like. The cartilage conduction vibration source  225  is arranged to be in contact with the lower part of the vibration conductor  227 , the vibration thereof being conducted to the vibration conductor  227 . The cartilage conduction vibration source  225  is constituted so as not to protrude from the outer wall of the mobile telephone (front view shown in  FIG. 7 ) and hinder the design, similarly with respect to the first to third embodiments, but the vibration of the cartilage conduction vibration source  225  is transmitted laterally by the vibration conductor  227 , causing the two ends  224  and  226  thereof to vibrate. The two ends  224  and  226  of the vibration conductor  227  are located on the inner angle of the top part  7  of the mobile telephone  301 , which is in contact with the tragus, and therefore, similarly with respect to the first to third embodiments, effectively come into contact with the tragus without protruding from the outer wall of the mobile telephone. In this manner, the right end part  224  and left end part  226  of the vibration conductor  227  respectively constitute the right-ear cartilage-conduction vibration unit  24  and left-ear cartilage-conduction vibration unit  26  mentioned in the first embodiment. However, because the vibration conductor  227  does not vibrate only at the right end  224  and left end  226  thereof but vibrates as a whole, it is possible in the fourth embodiment to transmit audio information regardless of where on the top inner edge of the mobile telephone  301  contact with the ear cartilage is made. Because the vibration of the cartilage conduction vibration source  225  is guided to a desired location by the vibration conductor  227 , and no requirement is made that the cartilage conduction vibration source  225  itself be arranged on the outer wall of the mobile telephone  301 , the configuration of such a cartilage conduction vibration unit is advantageous in that a greater amount of freedom is provided for the layout and in that the cartilage conduction vibration unit can be installed on a mobile telephone lacking any available extra space. 
     The fourth embodiment adds two further functionalities. However, these functionalities are not specific to the fourth embodiment, and can be applied to the first to third embodiments as well. One of the additional functionalities serves to prevent accidental operation of the cartilage conduction vibration unit. All of the first to fourth embodiments detect when the mobile telephone is brought up against an ear using the infrared light emitting units  19 ,  20  and the infrared light proximity sensor  21 ; however, in the first embodiment, for example, there is a concern that the proximity sensor will detect a case in which the inside of the mobile telephone  1  is lowered and placed on a desk or the like, and will accordingly falsely confirm that the mobile telephone  1  has been brought up against an ear, proceeding from step S 22  of the flow of  FIG. 4  to step S 24 . Because the same is not also true for the incline of the right ear call state detected in step S 24 , there is a possibility that the flow will proceed to step S 30  and the left-ear cartilage-conduction vibration unit  26  will erroneously be turned on. The vibration of the cartilage conduction vibration unit results in a comparatively large amount of energy, so vibration noise may be created with the desk when such mistaken operation occurs. To prevent this, the fourth embodiment is configured such that a horizontal stationary state is detected using the acceleration sensor  49 , and, when applicable, the cartilage conduction vibration source  225  is prohibited from vibrating. This point will be described in greater detail later. 
     Next, a description will be provided for the second additional functionality in the fourth embodiment. In each of the embodiments of the present invention, audio information is transmitted by having either the right-ear cartilage-conduction vibration unit  24  or the left-ear cartilage-conduction vibration unit  26  (in the fourth embodiment, the right end part  224  or left end part  226  of the vibration conductor  227 ) brought into contact with the tragus of the right ear or left ear; however, the contact pressure can be increased to obstruct the hole of the ear with the tragus, thereby creating an earplug bone conduction effect and conducting the audio information at an even higher volume. Further, because environment noise is blocked by the obstruction of the ear hole with the tragus, use in such a state achieves a listening status with dual effects, in which unnecessary environment noise is reduced and necessary audio information is increased; and is appropriate, for example, for calls to take place noisy environments or other situation. When the earplug bone conduction effect occurs, one&#39;s own voice becomes louder due to bone conduction from the vocal cords, and there is also a discomfort from the resulting imbalance in left and right auditory sensation. To ease the discomfort of one&#39;s own voice during the occurrence of such an earplug bone conduction effect, the fourth embodiment is configured such that the information of one&#39;s own voice picked up from the outgoing-talk unit  23  is subjected to phase inversion and transmitted to the cartilage conduction vibration source  225 , canceling out the sound of one&#39;s own voice. This point will be described in greater detail later. 
       FIG. 8  is a block diagram of the fourth embodiment, in which the same reference numerals are assigned to the same parts from  FIG. 7 . Also, because there are many portions in common with the first to third embodiments, corresponding portions are each assigned these same reference numerals. A description has been omitted for these identical or shared portions, unless there is a particular need. Although the telephone function unit  45  is illustrated in somewhat greater detail in the fourth embodiment, the configuration is shared among the first to third embodiments. More specifically, the incoming-talk-processing unit  212  and the earphone  213  of  FIG. 8  correspond to the incoming-talk unit  13  in  FIG. 3 , and the outgoing-talk-processing unit  222  and the microphone  223  in  FIG. 8  correspond to the outgoing-talk unit  23  in  FIG. 3 . On the other hand, the cartilage conduction vibration source  225  and the vibration conductor  227  in  FIG. 7  are depicted together in  FIG. 8  as the cartilage conduction vibration unit  228 . The outgoing-talk-processing unit  222  transmits a part of the audio from the operator picked up by the microphone  223  to the incoming-talk-processing unit  212  as a sidetone, and the incoming-talk-processing unit  212  superimposes the operator&#39;s own sidetone onto the voice of the calling party from the telephone communication unit  47  and outputs same to the earphone  213 , whereby the balance between the bone conduction and air conduction of one&#39;s own voice in the state in which the mobile telephone  301  is brought up against an ear is made to approximate a natural state. 
     The outgoing-talk-processing unit  222  further outputs a part of the audio from the operator picked up by the microphone  223  to an acoustics adjustment unit  238 . The acoustics adjustment unit  238  adjusts the acoustics of one&#39;s own voice, which are to be outputted from the cartilage conduction vibration unit  228  and transmitted to the cochlea, to acoustics approximating the operator&#39;s own voice transmitted to the cochlea by internal body conduction from the vocal cords during the occurrence of the earplug bone conduction effect; and effectively cancels out both. Also, a waveform inverter  240  subjects one&#39;s own voice, the acoustics of which have been adjusted in this manner, to waveform inversion, and outputs same to the phase adjustment mixer unit  236 . When the pressure detected by a pressure sensor  242  is at or above a predetermined range and the state corresponds to one in which the ear hole is obstructed at the tragus by the mobile telephone  301 , the phase adjustment mixer unit  236  mixes the output from the waveform inverter  240  according to an instruction from the controller  239  and drives the cartilage conduction vibration unit  228 . The excessive amount of one&#39;s own voice that occurs during the earplug bone conduction effect is thereby cancelled out, thus easing the discomfort. At this time, the degree of cancellation is regulated such that an amount of one&#39;s own voice equivalent to the sidetone remains without being cancelled out. On the other hand, a case in which the pressure detected by the pressure sensor  242  is lower than the predetermined level corresponds to a state in which the ear hole is not obstructed at the tragus and the earplug bone conduction effect does not occur; therefore, the phase adjustment mixer unit  236  will not mix the wavelength inversion output of one&#39;s own voice from the waveform inverter  240 , on the basis of the instruction of the controller  239 . However, the configuration may reverse the positions of the acoustics adjustment unit  238  and the waveform inverter  240  in  FIG. 8 . Moreover, the acoustics adjustment unit  238  and the waveform inverter  240  may be integrated as a function within the phase adjustment mixer unit  236 . 
       FIG. 9  is a conceptual block diagram illustrating the elements of the state in which the mobile telephone  301  is brought up against the tragus of the right ear in the fourth embodiment, and provides a description of how one&#39;s own voice is cancelled out during the occurrence of the earplug bone conduction effect.  FIG. 9  also depicts a particular embodiment of the pressure sensor  242 ; the configuration assumes that the cartilage conduction vibration unit  225  is a piezoelectric bimorph element. Equivalent parts have been given like reference numerals as in  FIGS. 7 and 8 , and a description has been omitted unless there is a particular need. 
       FIG. 9A  illustrates the state in which the mobile telephone  301  is brought up against the tragus  32  to such an extent that the tragus  32  does not obstruct the ear hole  232 . In such a state, the phase adjustment mixer unit  236  drives the cartilage conduction vibration unit  225  on the basis of the audio information of the calling party from the incoming-talk-processing unit  212 . The pressure sensor  242  is configured so as to monitor a signal appearing on a signal line linking the cartilage conduction vibration unit  225  to the phase adjustment mixer unit  236 , and detects signal variations that are based on strain to the cartilage conduction vibration unit (a piezoelectric bimorph element)  225  that is applied depending on the pressure on the vibration conductor  227 . Thus, when the cartilage conduction vibration unit  225  for transmitting audio information by being brought into contact with the tragus  32  comprises a piezoelectric bimorph element, the piezoelectric bimorph element can be made to also serve as a pressure sensor for detecting the pressure on the tragus  32 . The pressure sensor  242  further monitors a signal appearing on a signal line linking the incoming-talk-processing unit  212  to the phase adjustment mixer unit  236 . The signal appearing therein is not affected by the pressure on the tragus  32  and can therefore be utilized as a reference signal for determining the pressure. 
     In  FIG. 9A , as described above, the tragus  32  is in a state that does not obstruct the ear hole  232 , and the pressure sensor  242  determines that the pressure is small; therefore, on the basis of this determination, the controller  239  instructs the phase adjustment mixer unit  236  not to mix one&#39;s own waveform-inverted voice from the waveform inverter  240  into the cartilage conduction vibration unit  225 . On the other hand,  FIG. 9B  illustrates the state in which the mobile telephone  301  presses more strongly on the tragus  32  in the direction of arrow  302  and the tragus  32  obstructs the ear hole  232 . This state generates the earplug bone conduction effect. The pressure sensor  242  determines that the ear hole  232  has been obstructed on the basis of a detection of an increase to or above a predetermined pressure, and, on the basis of this determination, the controller  239  instructs the phase adjustment mixer unit  236  to mix one&#39;s own waveform-inverted voice from the waveform inverter  240  into the cartilage conduction vibration unit  225 . The discomfort of one&#39;s own voice during the occurrence of the earplug bone conduction effect is eased as described above. Conversely, when a reduction at or above a predetermined pressure from the state in  FIG. 9B  is detected by the pressure sensor  242 , the state is determined to be one in which, as in  FIG. 9A , the ear hole  232  is not obstructed, and the mixing of one&#39;s own waveform-inverted voice is discontinued. However, the pressure sensor  242  determines that there has been a transition between the states of  FIGS. 9A and 9B  on the basis of the absolute amount of pressure and the directionality of the pressure change. However, in a state of silence in which neither party speaks, the pressure sensor  242  detects the pressure by directly applying a pressure monitor signal, which is inaudible by ear, to the direct bone conduction vibration unit  225 . 
       FIG. 10  is a flow chart of the operation of the controller  239  in the fourth embodiment of  FIG. 8 . However, because the flow of  FIG. 10  has many points in common with the flow of the first embodiment in  FIG. 4 , corresponding parts have been given like step numerals, and a description has been omitted unless needed.  FIG. 10  also illustrates an abstraction of the operation that focuses on related functions, in order to primarily provide a description of the function of the cartilage conduction vibration unit  228 . Accordingly, similarly with respect to the case in  FIG. 4 , the controller  239  also contains typical mobile telephone functions and other operations not represented by the flow of  FIG. 10 .  FIG. 10  uses boldface print to illustrate points of difference with  FIG. 4 , and thus the following description focuses on these portions. 
     Step S 42  integrates step S 6  and step S 8  of  FIG. 4 , and is therefore illustrated such that the non-call processing of step S 42  includes the case of directly proceeding to the next step without any non-call operation, but the content thereof is identical to step S 6  and step S 8  in  FIG. 4 . Step S 44  integrates step S 10  and step S 12  of  FIG. 4 , and is therefore illustrated as a step for checking the presence or absence of a call state between two parties regardless of whether the call is incoming from the other party or is outgoing from oneself, but the content thereof is identical to step S 6  and step S 8  in  FIG. 4 . However, the fourth embodiment does not contain a step that would correspond to step S 16  in  FIG. 4 , because the configuration is not such that the mobile telephone  301  is opened or closed. 
     Step S 46  relates to the first addition function in the fourth embodiment and therefore checks for whether the mobile telephone  301  has left the hand-held state and remained stationary in a horizontal state for a predetermined period of time (for example, 0.5 seconds). When the proximity sensor has made a detection in step S 22 , step S 48  is first reached in a case in which it is confirmed in step S 46  that there is no such horizontal stationary state; the cartilage conduction vibration source  225  is then turned on. On the other hand, in a case in which a horizontal stationary state is detected in step S 46 , the flow proceeds on to step S 50 , which turns off the cartilage conduction vibration source  225 , and the flow returns to step S 14 . However, step S 50  corresponds to when, in a flow repetition to be described later, the cartilage conduction vibration source  225  reaches step S 46  in an on state and a horizontal stationary state has been detected; therefore, when the cartilage conduction vibration source  225  reaches step S 50  in an off state, the flow returns to step S 14  without any action being performed. 
     Step S 52  relates to the second added function in the fourth embodiment, and checks for the occurrence of the earplug bone conduction effect, which is caused by the mobile telephone  301  pressing strongly on the tragus  32  and obstructing the ear hole  232 . In particular, as illustrated in  FIG. 9 , this is checked by the presence or absence of a change at or above a predetermined pressure and the directionality thereof by the pressure sensor  242 . In a case in which there is a detection of the state in which the earplug bone conduction effect is created, the flow proceeds to step S 54 , which adds the waveform-inversion signal of one&#39;s own voice to the cartilage conduction vibration source  225 , and the flow then moves on to step S 58 . On the other hand, in a case in which there is a detection in step S 52  of a state in which the earplug bone conduction effect is not created, the flow moves on to step S 56 , and then on to step S 58  without adding the waveform-inversion signal of one&#39;s own voice to the cartilage conduction vibration source  225 . In step S 58 , there is performed a check for whether or not a call state has been cut off; when the call is not cut off, the flow returns to step S 22 , following which step S 22  and step S 46  to S 58  are repeated until a call interruption is detected in step S 58 . Support is thereby provided for the generation and elimination of the earplug bone conduction effect during a call. 
     The various features of each of the embodiments described above are not to be restricted to individual respective embodiments, but rather can be substituted or combined with other appropriate embodiments. For example, the flow chart of the fourth embodiment in  FIG. 10  does not have the configuration in the flow chart of the first embodiment in  FIG. 4  for switching the right-ear cartilage-conduction vibration unit  24  and the left-ear cartilage-conduction vibration unit  26 , but the configuration may be such that the right-ear cartilage-conduction vibration unit  24  and the left-ear cartilage-conduction vibration unit such as in the first embodiment are utilized as the configuration of the cartilage conduction vibration unit  228  in the tenth embodiment; thus, in addition to support for the generation and elimination of the earplug bone conduction effect in repeating the loop of step S 22  and steps S 46  to S 58 , support is additionally provided for switching the mobile telephone to the other hand between the right ear call state and the left ear call state by the function according to steps S 24  to S 26  from  FIG. 4 . It is also possible to add to the first to third embodiments the functionality of checking for the horizontal stationary state and turning off the cartilage conduction vibration unit  228  in the fourth embodiment of  FIG. 10 . It is moreover possible in the first through third embodiments to utilize the cartilage conduction vibration unit  228  as in the fourth embodiment. 
     Fifth Embodiment 
       FIG. 11  is a perspective view illustrating a fifth embodiment of the mobile telephone according to an aspect of the present invention. The fifth embodiment is founded on the fourth embodiment of  FIG. 7 , and shares the majority of the structure thereof; thus, corresponding parts have been given like reference numerals, and a description thereof has been omitted. Also, to avoid complicating the illustration, the assignment of the reference numerals themselves has also been omitted for those portions for which the description has been omitted, but the functions and names of the common parts in the drawings are common with  FIG. 7 . However, a more detailed description of the configuration calls on the essential points of the block diagram of the fourth embodiment in  FIGS. 8 and 9 . A first point of difference in the fifth embodiment from the fourth embodiment lies in that a mobile telephone  401  is provided with a double-push button  461 , which makes it possible to set a so-called touch panel function (a function in which the large-screen display unit  205 , on which the key pad or other operation unit  209  is displayed, is touched with a finger and the GUI is operated by the detection of this touch position and/or the detection of this swipe) to off, and also which is only usable when this touch panel function has been set to off. The touch panel function can be set to off by operating the touch panel itself, and the touch panel can also be set to return to on by pressing the double-push button  461  for a predetermined period of time or longer. The double-push button  461 , when usable, also has a function for initiating a call with a first push and for interrupting a call when there is a second push during the call (an alternate switching function performed by pushing whether [the device] is on or off). The above-described first push of the double-push button  461  is performed either to call a specific party or to respond to an incoming call, a call being initiated thereby in either case. 
     A second point of difference in the fifth embodiment from the fourth embodiment lies in that the fifth embodiment is configured so as to function by the combination of the mobile telephone  401  with a softcover  463  for housing same. Although  FIG. 11 , for the sake of describing the configuration, depicts the softcover  463  as if it were transparent, the softcover  463  is actually opaque, and the mobile telephone  401  cannot be seen from the outside in the state in which the mobile telephone  401  is housed in the softcover  463  as in  FIG. 11 . 
     The above-described double-push button  461  is also able to function when the double-push button  461  is pushed from on the softcover  463  in the state in which the mobile telephone  401  has been housed in the softcover  463 . Furthermore, the softcover  463  is configured so as to interlock with the cartilage conduction vibration unit  228  comprising the cartilage conduction vibration source  225  and vibration conductor  227  of the mobile telephone  401 , allowing for a call to take place in the state in which the mobile telephone  401  is housed in the softcover  463 . The following provides a description thereof. 
     The softcover  463  is made using an elastic material that has acoustic impedance approximating that of ear cartilage (a silicone rubber; a mixture of a silicone rubber and a butadiene rubber; a natural rubber; a structure formed using these varieties of rubber in which air bubbles are sealed; a structure, such as can be seen in transparent packaging sheet materials or the like, in which a layer of groups of air bubbles is sealed separated by a thin film of synthetic resin; or the like). The vibration conductor  227  for transmitting vibration from the cartilage conduction vibration source  225  is in contact with the inside of the softcover when the mobile telephone  401  is housed therein. The outside of the softcover  463  is brought up against the ear with the mobile telephone  401  housed therein, whereby the vibration of the vibration conductor  227  is transmitted to the ear cartilage over a broad area of contact by the interposition of the softcover  463 . Sound from the exterior of the softcover  463 , which resonates in accordance with the vibration of the vibration conductor  227 , is further transmitted to the tympanic membrane from the external auditory meatus. Sound source information from the cartilage conduction vibration source  225  can thereby be heard as a loud sound. Environment noise can also be blocked, because the softcover  463 , which is brought up against the ear, has a form such that the external auditory meatus is obstructed. Increasing the force with which the softcover  463  is pressed against the ear furthermore gives the result of substantially completely obstructing the external auditory meatus, and sound source information from the cartilage conduction vibration source  225  can be heard as an even louder sound due to the earplug bone conduction effect. Detection is done via the softcover  463 , but, similarly with respect to the fourth embodiment, in the state in which the earplug bone conduction effect is created, the waveform inversion signal from the outgoing-talk unit  23  (the microphone  223 ) is added to the signal of one&#39;s own voice, on the basis of the detection of pressure by the cartilage conduction vibration source  225 . 
     In a call state in which the mobile telephone  401  remains housed in the softcover  463 , the vibration of the vibration conductor  227 , which is transmitted to the softcover  463 , is also transmitted to the outgoing-talk unit  23 , which has the potential to generate a Larsen effect. To block acoustic conduction between the vibration conductor  227  and the outgoing-talk unit  23  as a countermeasure therefor, the softcover  463  is provided in between the two with an insulation ring unit  465  having an acoustic impedance different from that of the body of the softcover. The insulation ring unit  465  can be formed by either integrating or joining a material different from the material of the body of the softcover. The insulation ring unit  465  may also be formed by joining a layer having a different acoustic impedance to either the outside or the inside of the softcover  463 , which are molded with the same material. Moreover, a plurality of insulation ring units  465  may be interposed between the vibration conductor  227  and the outgoing-talk unit  23  so that the insulating effect may be increased. 
     In order for the softcover  463  to permit a call to take place in the state in which the mobile telephone  401  remains housed therein, the vicinity of the outgoing-talk unit  23  (the microphone  223 ) is configured as a microphone cover unit  467 , which does not interfere with the air conduction of sound. Such a microphone cover unit  467  takes a sponge-like structure such as that of, for example, an earphone cover or the like. 
       FIG. 12  is a flow chart of the operation of the controller  239  (borrowing from  FIG. 8 ) in the fifth embodiment of  FIG. 11 . However, parts that the flow of  FIG. 12  shares with the flow of  FIG. 10  have been given like step reference numerals, and a description thereof has been omitted.  FIG. 12  also primarily serves to describe the functions of the cartilage conduction vibration unit  228  and therefore depicts an abstraction of the operation that focuses on the related functions. Accordingly, similarly with respect to  FIG. 10  or the like, the controller  239  in the fifth embodiment also contains typical mobile telephone functions and other operations that are not represented in the flow in  FIG. 12 . 
     When the flow of  FIG. 12  reaches step S 62 , a check is performed for whether or not the touch panel has been set to off by the operation described above. When same has not been set to off, the flow moves on to step S 64 , and the function of the double-push button  461  is deactivated, whereupon the flow moves on to step S 66  before arriving at step S 34 . The portion illustrated as typical processing in step S 66  collectively integrates step S 14 , steps S 18  to S 22 , step S 32 , step S 36 , step S 38 , and steps S 42  to S 58  in  FIG. 10  (i.e., the portions between steps S 4  and S 34 ). In other words, in a case in which step S 62  transitions to step S 64 , the flow in  FIG. 12  implements similar functions to those of  FIG. 10 . 
     On the other hand, when it is detected in step S 62  that the touch panel has been set to off, the flow moves on to step S 68 , in which the function of the double-push button  461  is activated. The flow then proceeds to step S 70 . In step S 70 , the function of the touch panel is deactivated, and in step S 72 , the presence or absence of a first push on the double-push button  461  is detected. In a case in which herein no push is detected, the flow moves on directly to step S 34 . On the other hand, in a case in which a first push on the double-push button  461  is detected in step S 72 , the flow proceeds to step S 74 , which detects whether or not the mobile telephone  401  has been housed in the softcover  463 . This detection is made possible, for example, by the function of the infrared light-emitting units  19 ,  20  and the infrared light proximity sensor  21 , which constitute the proximity sensor. 
     When housing in the softcover  463  is detected in step S 74 , the flow proceeds to step S 76 , which turns the outgoing-talk unit  23  on, and turns the incoming-talk unit  13  off. Further, step S 78  turns the cartilage conduction vibration source  225  on and the flow proceeds to step S 80 , which places the mobile telephone  401  in a call state. When a call state is already in effect, the same is continued. On the other hand, in a case in which housing in the softcover  463  is not detected in step S 74 , the flow moves on to step S 82 , which turns both the outgoing-talk unit  23  and the incoming-talk unit  13  on; further, step S 84  turns the cartilage conduction vibration source  225  off and the flow proceeds to step S 80 . Step S 86 , which follows step S 80 , runs processing for the earplug bone conduction effect, and then the flow moves on to step S 88 . The processing for the earplug bone conduction effect in step S 86  is collectively illustrated by steps S 52  to S 56  in  FIG. 10 . 
     In step S 88 , the presence or absence of a second push on the double-push button  461  is detected. When there is no detection, the flow returns to step S 74 , following which steps S 74  to S 88  are repeated until there is a detection of a second push on the double-push button  461 . There is a constant check for whether the mobile telephone  401  is housed in the softcover  463  during this repetition during a call; therefore, when, for example, environment noise is loud and listening comprehension at the incoming-talk unit  13  is impaired, support is provided for the user to house the mobile telephone  401  in the softcover  463  and thereby block environment noise and further ease listening comprehension by the earplug bone conduction effect. 
     On the other hand, when a second push on the double-push button  461  is detected in step S 88 , the flow moves on to step S 90 , which interrupts the call; step S 92  also turns all sending and receiving functions off and the flow arrives at step S 34 . In step S 34 , there is performed a check for whether the primary power source is off; therefore, when there is no detection of the primary power source being off, the flow returns to step S 62 , following which steps S 62  to S 92  and step S 34  are repeated. Further, during this repetition, step S 64  provides support for setting the touch panel to off by the previously described operation of the touch panel or for releasing the off setting by a long press on the double-push button  461 , and therefore switch is possible with appropriate, ordinary processing. 
     Sixth Embodiment 
       FIG. 13  is a perspective view illustrating a sixth embodiment of the mobile telephone according to an aspect of the present invention.  FIG. 13A  is a front perspective view similar to  FIG. 7 , but, as will be described later, because the sixth embodiment is constituted as a digital camera provided with mobile telephone functions,  FIG. 13A  is rotated 90 degrees relative to  FIG. 7  and depicted at the angle of the state of use as a digital camera.  FIG. 13B  is a rear perspective view thereof (a front perspective view in a case viewed as a digital camera), and  FIG. 13C  is a cross-sectional view in the B-B sectional plane in  FIG. 13B . 
     The sixth embodiment is founded on the fourth embodiment of  FIG. 7 , and has the majority of the structure thereof in common; thus, corresponding parts have been given like reference numerals, and a description thereof has been omitted. Also, to avoid complicating the illustration, the assignment of the reference numerals themselves has also been omitted for those portions for which the description has been omitted, but the functions and names of the common parts in the drawings are in common with those of  FIG. 7 . However, a more detailed description of the configuration calls on the essential points of the block diagram of the fourth embodiment in  FIGS. 8 and 9 . A first point of difference in the sixth embodiment from the fourth embodiment lies in that a mobile telephone  501  is constituted as a digital camera provided with mobile telephone functions. That is, as illustrated in  FIG. 13B , the first point of difference is that a zoom lens  555  provided with high optical performance is utilized as the imaging lens of the backside main camera. The zoom lens  555  projects out during use in the state illustrated by the single dotted line in  FIG. 13B , but, during non-use, takes a so-called collapsible lens configuration, which retracts to a position forming a plane identical to that of the outer surface of the mobile telephone  501 . A strobe  565  and a shutter release button  567  for projecting auxiliary light when the subject is dark are also provided. The mobile telephone  501  also has a grip unit  563  suited for when the camera is held in the right hand. 
     A second point of difference in the sixth embodiment from the fourth embodiment lies in that the grip unit  563 , similarly with respect to the softcover  463  in the fifth embodiment, is made using a material that has acoustic impedance approximating that of ear cartilage (a silicone rubber; a mixture of a silicone rubber and a butadiene rubber; a natural rubber; or a structure formed from these varieties of rubber in which air bubbles are sealed), and is provided with an elasticity suited for providing a satisfactory grip sensation. Also, unlike the arrangement in the fourth embodiment, a cartilage conduction vibration source  525  is arranged on the reverse side of the grip unit  563 . As is clear from the cross-section in  FIG. 13C , the cartilage conduction vibration source  525  is in contact with the rear side of the grip unit  563 . 
     Accordingly, bringing the grip unit  563  up against the ear transmits the vibration of the cartilage conduction vibration source  525  to the ear cartilage over a broad area of contact by the interposition of the grip unit  563 . Moreover, sound from the exterior of the grip unit  563 , which resonates according to the vibration of the cartilage conduction vibration source  525 , is transmitted to the tympanic membrane from the external auditory meatus. Sound source information from the cartilage conduction vibration source  525  can thereby be heard as a loud sound. Also, similarly with respect to the fifth embodiment, the grip unit  563 , which is brought up against the ear, takes on a form such that the external auditory meatus is obstructed, and can therefore block environment noise. Further similarly with respect to the fifth embodiment, increasing the force for pressing the grip unit  563  gives the result of substantially completely obstructing the external auditory meatus, and sound source information from the cartilage conduction vibration source  525  can be heard as an even louder sound due to the earplug bone conduction effect. Detection is made via the grip unit  563 , but, similarly with respect to the fifth embodiment, in the state in which the earplug bone conduction effect is created, the waveform inversion signal from a microphone or other outgoing-talk unit  523  is added to the signal of one&#39;s own voice, on the basis of the detection of pressure by the cartilage conduction vibration source  525 . 
     Unlike the fourth embodiment, the outgoing-talk unit  523  is provided not to the front surface of the mobile telephone  501  but rather to the end surface thereof, as is clear from  FIG. 13B . Accordingly, the outgoing-talk unit  523  can consistently pick up the user&#39;s voice both when the incoming-talk unit  13  is brought up against the ear for a call and when the grip unit  563  on the reverse side is brought up against the ear for a call. The settings can be switched using a switch button  561  for either activating the incoming-talk unit  13  or for activating the cartilage conduction vibration source  525 . In the state in which the zoom lens  555  projects in the state illustrated by the single dotted line in  FIG. 13B , it is inappropriate to bring the grip unit  563  up against the ear for a call; therefore, when the switch button is operated in such a state and the setting is changed to activate the cartilage conduction vibration source  525 , the zoom lens  555  collapses automatically, the execution of this switch being reserved until the collapse is complete. 
       FIG. 14  is a flow chart of the operation of the controller  239  (borrowing from  FIG. 8 ) in the sixth embodiment of  FIG. 13 . However, parts that the flow of  FIG. 14  shares with the flow of  FIG. 10  have been given like step reference numerals, and a description thereof has been omitted.  FIG. 14  also illustrates an abstraction of the operation that focuses on related functions, in order to primarily provide a description of the function of the cartilage conduction vibration unit  228 . Accordingly, similarly with respect to  FIG. 10  and the like, in the sixth embodiment as well, the controller  239  also contains typical mobile telephone functions and other operations not represented by the flow in  FIG. 14 . 
     In the flow of  FIG. 14 , there is performed a check for whether there has been an operation to initiate a call once step S 104  is reached. In a case in which there has not been an operation, the flow moves directly on to step S 34 . On the other hand, in a case in which an operation to initiate a call is detected, the flow proceeds to step S 106 , in which there is performed a check for whether the cartilage conduction has been set using the switch button  561 . When the cartilage conduction has been set, there is a check in step S 108  for whether the zoom lens  555  is projecting out. A result in which the zoom lens  555  is not projecting out moves on to step S 110 , in which the outgoing-talk unit  523  is turned on and the incoming-talk unit  13  is turned off; step S 112  turns the cartilage conduction vibration source  525  on and then the flow moves on to step S 46 . 
     On the other hand, in a case in which no cartilage conduction setting is detected in step S 106  the flow moves on to step S 114 , in which the outgoing-talk unit  523  and the incoming-talk unit  13  are turned on; step S 116  turns the cartilage conduction vibration source  525  off and the flow moves on to step S 118 . Furthermore, in a case in which it is detected in step S 108  that the zoom lens  555  is projecting out when it is also detected in step S 106  that the cartilage conduction has been set, the flow moves on to step S 111 , which instructs that the zoom lens  555  be collapsed, and the flow moves on to step S 114 . However, in a case in which collapsing has already been initiated, the instruction is that same be continued. As will be described later, steps S 106  to S 116  are repeated until the call state is cut off. Thus, there is an instruction to collapse in step S 111  in accordance with a cartilage conduction setting detection in step S 106 , and after the collapsing has been initiated, the state of steps S 114  and S 116  is maintained without the flow moving on to step S 110  until the collapsing is completed and the projection of the zoom lens  555  is no longer detected in step S 108 . 
     Steps S 46  to S 56 , which follow step S 112 , are consistent with  FIG. 10  and therefore a description thereof has been omitted. Upon the move to step S 54  or steps S 56  to S 118 , a check is done for whether the call state has been cut off, and in a case in which a call interruption is not detected, the flow returns to step S 106 , following which steps S 106  to S 118  and steps S 46  to S 56  are repeated. When, for example, environment noise is loud and when listening comprehension is impaired at the incoming-talk unit  13 , support can thereby be provided for the user to operate the switch button  561  during a call to switch to the cartilage conduction setting and thereby block environment noise or further ease listening comprehension by the earplug bone conduction effect, and the like. Also, at this time the zoom lens  555  is automatically collapsed when in the projecting state. 
     Seventh Embodiment 
       FIG. 15  is a perspective view illustrating a seventh embodiment of a mobile telephone according to an aspect of the present invention. A mobile telephone  601  of the seventh embodiment, similarly with respect to the first embodiment, is configured such that an upper part  607  can be folded onto a lower part  611  by a hinge unit  603 .  FIG. 15A  is a front perspective view similar to  FIG. 1 , and  FIG. 15B  is a rear perspective view thereof.  FIG. 15C  is a cross-sectional view of the elements in the B-B sectional plane in  FIG. 15B . The majority of the structure of the seventh embodiment is shared with that of the first embodiment, and therefore corresponding parts have been assigned the same reference numerals, and a description has been omitted. Also, to avoid complicating the illustration, the assignment of the reference numerals themselves has also been omitted for those portions for which the description has been omitted, but the functions and names of the common parts in the drawings are common with  FIG. 1 . Furthermore, although the overview is shared with the first embodiment, a more detailed description of the internal configuration calls on the essential points of the block diagram of the fourth embodiment in  FIGS. 8 and 9 . 
     A first point of difference in the seventh embodiment from the first embodiment lies in that, as depicted in  FIG. 15B , a cartilage conduction output unit  663  having a broad surface area is provided in the vicinity of the hinge of the upper part  607 . The cartilage conduction output unit  663  is similar to the softcover  463  in the fifth embodiment and/or to the grip unit  563  in the sixth embodiment, and is made using a material that has acoustic impedance approximating that of ear cartilage (a silicone rubber; a mixture of a silicone rubber and a butadiene rubber; a natural rubber; or a structure formed using these varieties of rubber in which air bubbles are sealed), and is provided with an elasticity suited for protecting against collision of a foreign object against the outer wall of the mobile telephone  601 . Unlike the arrangement in the first embodiment, a cartilage conduction vibration source  625  is arranged behind the cartilage conduction output unit  663 . As is clear from the cross-section of  FIG. 15C , the cartilage conduction vibration source  625  is in contact with the rear surface of the cartilage conduction output unit  663 . 
     Accordingly, folding the mobile telephone  601  and bringing the cartilage conduction output unit  663  up against the ear transmits the vibration of the cartilage conduction vibration source  625  to the ear cartilage over a broad area of contact by the interposition of the cartilage conduction output unit  663 . Sound from the exterior of the cartilage conduction output unit  663 , which resonates in accordance with the vibration of the cartilage conduction vibration source  625 , is further transmitted to the tympanic membrane from the external auditory meatus. Sound source information from the cartilage conduction vibration source  625  can thereby be heard as a loud sound. Also, similarly with respect to the fifth embodiment and the sixth embodiment, the cartilage conduction output unit  663 , which is brought up against the ear, takes on a form such that the external auditory meatus is obstructed, and can therefore block environment noise. Further similarly with respect to the fifth embodiment and the sixth embodiment, increasing the force with which the cartilage conduction output unit  663  is pressed to the ear gives the result of substantially completely obstructing the external auditory meatus, and sound source information from the cartilage conduction vibration source  625  can be heard as an even louder sound due to the earplug bone conduction effect. Detection is done via the cartilage conduction output unit  663 , but, similarly with respect to the fifth embodiment and the sixth embodiment, in the state in which the earplug bone conduction effect is created, the waveform inversion signal from a microphone or other outgoing-talk unit  623  is added to the signal of one&#39;s own voice, on the basis of the detection of pressure by the cartilage conduction vibration source  625 . 
     A second point of difference in the seventh embodiment from the first embodiment lies in that, as depicted in  FIG. 15A , the outgoing-talk unit  623  is provided to the lower end surface of the lower part  611 , rather than to the front surface of the lower part  611  of the mobile telephone  601 . Accordingly, the outgoing-talk unit  623  can consistently pick up the user&#39;s voice both when the mobile telephone  601  is opened and the incoming-talk unit  13  is brought up against the ear for a call and when the mobile telephone  601  is closed and the cartilage conduction output unit  663  is brought up against the ear for a call. In a case in which the mobile telephone  601  is set to support switching cartilage conduction, switching occurs automatically such that the incoming-talk unit  13  is activated when the mobile telephone  601  is opened and a cartilage conduction vibration source  625  is activated when the mobile telephone  601  is closed. On the other hand, in a case in which there is no setting to support switching the cartilage conduction, the cartilage conduction vibration source  525  will not automatically be activated; rather, ordinary speaking and listening function regardless of whether the mobile telephone  601  is open or closed. 
     As is clear from the rear perspective view in  FIG. 15B , the back surface of the mobile telephone  601  is provided with a backside main camera  55 , a speaker  51 , and a back surface display unit  671 . The back surface of the mobile telephone  601  is further provided with a pushbutton  661 , which becomes active when the cartilage conduction switching support is set and the mobile telephone  601  is closed. Similarly with respect to the fifth embodiment, the pushbutton  661  has the functions of initiating a call with a first push, and of interrupting a call when pushed a second time during a call. The first push of the pushbutton  661  is performed either to place an outgoing call to a specific party or to respond to an incoming call, a call being initiated thereby in either case. 
       FIG. 16  is a flow chart of the operation of the controller  239  (borrowing from  FIG. 8 ) in the seventh embodiment of  FIG. 15 . However, parts that the flow of  FIG. 16  shares with the flow of  FIG. 14  have been given like step reference numerals, and a description thereof has been omitted.  FIG. 16  also illustrates an abstraction of the operation that focuses on related functions, in order to primarily provide a description of the function of the cartilage conduction vibration unit  228 . Accordingly, in the seventh embodiment, the controller  239  also contains typical mobile telephone functions and other operations not represented by the flow of  FIG. 16 , similarly with respect to  FIG. 14  and the like. 
     In the flow of  FIG. 16 , a call is initiated and when step S 122  is reached, there is performed a check for whether cartilage conduction switching support has been set. In a case in which cartilage conduction switching support is confirmed to have been set in step S 122 , the flow proceeds to step S 124 , which checks for whether or not the mobile telephone  601  has been opened; i.e., has gone from the state in which the upper part  607  is folded on top of the lower part  611  to the state of being opened as in  FIG. 15 . In a case in which it is confirmed that the mobile telephone  601  has not been opened and the upper part  607  is folded on top of the lower part  611 , the flow moves on to step S 110 , which turns the outgoing-talk unit  623  on and turns the incoming-talk unit  13  off; step S 112  turns the cartilage conduction vibration source  625  on and then the flow moves on to step S 46 . In this manner, it becomes possible to listen using the cartilage conduction output unit  663  in the state in which the mobile telephone  601  is folded up. 
     On the other hand, in a case in which it is not detected in step S 122  that the cartilage conduction switching support has been set, no question is posed as to whether or not the mobile telephone  601  is folded up, but rather the flow moves on to step S 114 , which turns the outgoing-talk unit  623  and the incoming-talk unit  13  on together; step S 116  then turns the cartilage conduction vibration source  625  off and moves on to step S 118 . In a case in which it is detected in step S 106  that the cartilage conduction switching support has been set, the flow moves on to step S 114  even when it is confirmed in step S 124  that the mobile telephone  601  is open. 
     The flow in  FIG. 16  also has a check for whether or not the call state has been cut off in step S 118 ; the flow returns to step S 122  in a case in which a call interruption is not detected, following which step S 122 , step S 124 , steps S 114  to S 118  and steps S 46  to S 56  are repeated. In this manner, in a case in which the cartilage conduction switching support has been pre-set, when, for example, environment noise is loud and when listening comprehension is impaired at the incoming-talk unit  13 , support can be provided for the user to fold up the mobile telephone  601  during the course of a call and switch to listening by the cartilage conduction output unit  663 , and thereby block environment noise or further ease listening comprehension by the earplug bone conduction effect, and the like. 
     To summarize the features of the aforementioned fifth to sixth embodiments, the mobile telephone comprises a cartilage conduction vibration source and a conductor for guiding the vibration of the cartilage conduction vibration source to the ear cartilage; the conductor either is configured as an elastic body, or is large enough to be in contact with the ear cartilage at a plurality of points or is large enough to be in contact with the ear cartilage and obstruct the external auditory meatus, or has a surface area at least approximating that of an earlobe, or has an auditory impedance approximating the auditory impedance of ear cartilage. Any of these features or a combination thereof makes it possible to listen effectively to sound information by the cartilage conduction vibration source. The use of these features is also not to be limited to the above-described embodiments. For example, it is also possible to constitute the present invention without having the conductor be an elastic body, by the use of the advantages of the materials, sizes, surface areas, arrangements, and structures disclosed in the above-described embodiments. 
     Eighth Embodiment 
       FIG. 17  is a perspective view illustrating an eighth embodiment of the mobile telephone according to an aspect of the present invention. The eight embodiment is similar to the sixth embodiment of  FIG. 13 , and is configured as a digital camera provided with a mobile telephone function; similarly with respect to  FIG. 13 ,  FIG. 17A  is a front perspective view,  FIG. 17B  is a rear perspective view, and  FIG. 17C  is a cross-sectional view in the B-B sectional plane in  FIG. 17B . The eighth embodiment shares the majority of the structure with the sixth embodiment of  FIG. 13 ; thus, corresponding parts have been given like reference numerals, and a description thereof has been omitted. 
     The point of difference in the eighth embodiment from the sixth embodiment lies in that, as is clear from the cross-section of  FIG. 17C , a cartilage conduction vibration source  725  is embedded inside a grip unit  763 . The grip unit  763 , similarly with respect to the sixth embodiment in  FIG. 13 , is made using a material that has acoustic impedance approximating that of ear cartilage (a silicone rubber; a mixture of a silicone rubber and a butadiene rubber; a natural rubber; or a structure formed using these varieties of rubber in which air bubbles are sealed), and is provided with an elasticity suited for providing a satisfactory grip sensation. A more detailed description of the internal configuration, similarly with respect to the sixth embodiment, calls on the essential points of the block diagram of the fourth embodiment in  FIGS. 8 and 9 . 
     A flexible connection wire  769  in  FIG. 17C  connects the cartilage conduction vibration source  725 , which is embedded inside the grip unit  763 , with the phase adjustment mixer unit  236  of  FIG. 8  or other circuit portion  771 . The structure as illustrated by the cross-sectional view in  FIG. 17C , for embedding the cartilage conduction vibration source  725  inside the grip unit  763 , can be achieved by an integrated mold in which the cartilage conduction vibration source  725  and the flexible connection wire  769  are inserted into the grip unit  763 . The same can also be achieved by dividing the grip unit  763  into two bodies, where the flexible connection wire  769  and the cartilage conduction vibration source  725  serve as a boundary, and by bonding the two grip units  763  across the flexible connection wire  769  and the cartilage conduction vibration source  725 . 
     The eighth embodiment is similar to the sixth embodiment in that bringing the grip unit  763  up against the ear transmits the vibration of the cartilage conduction vibration source  725  to the ear cartilage over a broad area of contact by the interposition of the grip unit  763 ; in that sound from the exterior of the grip unit  763 , which resonates in accordance with the vibration of the cartilage conduction vibration source  725 , is further transmitted to the tympanic membrane from the external auditory meatus; in that environment noise can also be blocked, because the grip unit  763 , which is brought up against the ear, has a form such that the external auditory meatus is obstructed; and in that increasing the force pressing the grip unit  763  to the ear furthermore gives the result of substantially completely obstructing the external auditory meatus, and sound source information from the cartilage conduction vibration source  725  can be heard as an even louder sound due to the earplug bone conduction effect. In the state in which the earplug bone conduction effect is created, the adding of the waveform inversion signal from the microphone or other outgoing-talk unit  523  to the signal of one&#39;s own voice, on the basis of the detection of pressure by the cartilage conduction vibration source  625 , is the same as in the sixth embodiment. However, because the cartilage conduction vibration source  725  is embedded in the grip unit  763  in the eighth embodiment, the state in which the earplug bone conduction effect is created is detected by the strain to the cartilage conduction vibration source  725 , which is caused by the strain to the grip unit  763  due to an increase in the pushing force. 
     The significance of embedding the cartilage conduction vibration source  725  inside an elastic body such as the grip unit  763  in the eighth embodiment lies not only in obtaining a favorable conduction of sound, as described above, but also in counteracting impact on the cartilage conduction vibration source  725 . A piezoelectric bimorph element, which is used as the cartilage conduction vibration source  725  in the eighth embodiment, has properties for resisting impact. Herein, configuring the cartilage conduction vibration source  725  so as to be enveloped circumferentially, as in the eighth embodiment, can provide cushioning against impact resulting from the rigid structure of the mobile telephone  701 , and can facilitate implementation in the mobile telephone  701 , which is constantly exposed to such risks as being dropped. The elastic body enveloping the cartilage conduction vibration source  725  not only functions simply as a cushioning material, but also functions as a configuration for more effectively transmitting the vibration of the cartilage conduction vibration source  725  to the ear as described above. 
     Ninth Embodiment 
       FIG. 18  is a perspective view illustrating a ninth embodiment of a mobile telephone according to an aspect of the present invention. A mobile telephone  801  of the ninth embodiment, similarly with respect to the seventh embodiment, is configured such that an upper part  807  can be folded onto the lower part  611  by a hinge unit  603 . In  FIG. 18 , which is similar to  FIG. 15 ,  FIG. 18A  is a front perspective view,  FIG. 18B  is a rear perspective view, and  FIG. 18C  is a cross-sectional view in the B-B sectional plane in  FIG. 18B . The eighth embodiment in  FIG. 18  shares the majority of the structure with the seventh embodiment of  FIG. 15 ; thus, corresponding parts have been given like reference numerals, and a description thereof has been omitted. 
     A point of difference in the ninth embodiment from the seventh embodiment lies in that, as is clear from the cross-section of  FIG. 18C , a cartilage conduction vibration source  825  is sandwiched between a cartilage conduction output unit  863  and an internal cushioning material  873 . The cartilage conduction output unit  863 , similarly with respect to the cartilage conduction output unit  663  in the seventh embodiment, is made using a material that has acoustic impedance approximating that of ear cartilage (a silicone rubber; a mixture of a silicone rubber and a butadiene rubber; a natural rubber; or a structure formed using these varieties of rubber in which air bubbles are sealed), and is provided with an elasticity suited for protecting against the collision of a foreign object against the outer wall of the mobile telephone  801 . The internal cushioning material  873  can be constituted of any material provided that the material is an elastic body having the purpose of providing cushioning, but can also be made of the same material as the cartilage conduction output unit  863 . A more detailed description of the internal configuration, which is similar to the seventh embodiment, calls on the essential points of the block diagram of the fourth embodiment in  FIGS. 8 and 9 . 
     As illustrated by the cross-section in  FIG. 18C , the cartilage conduction vibration source  825  and a flexible connection wiring  869  are sandwiched in between the cartilage conduction output unit  863  and the internal cushioning material  873 . The flexible connection wire  869 , similarly with respect to the eighth embodiment, connects the cartilage conduction vibration source  825  with the phase adjustment mixer unit  236  of  FIG. 8  or other circuit portion  871 . These structures, in which the cartilage conduction vibration source  825  and the flexible connection wire  869  are sandwiched in between the cartilage conduction output unit  863  and the internal cushioning material  873 , are integrated within a cartilage conduction output unit  875 ; such a cartilage conduction output unit  875  is fitted into the upper part  807  of the mobile telephone  801 . 
     The ninth embodiment is also similar to the seventh embodiment in that bringing the cartilage conduction output unit  863  up against the ear transmits the vibration of the cartilage conduction vibration source  825  to the ear cartilage over a broad area of contact by the interposition of the cartilage conduction output unit  863 ; in that sound from the cartilage conduction output unit  863 , which resonates in accordance with the vibration of the cartilage conduction vibration source  825 , is transmitted to the tympanic membrane from the external auditory meatus; in that environment noise can be blocked, because the cartilage conduction output unit  863 , which is brought up against the ear, has a form such that the external auditory meatus is obstructed; and in that increasing the force pressing the cartilage conduction output unit  863  to the ear gives the result of substantially completely obstructing the external auditory meatus, and sound source information from the cartilage conduction vibration source  825  can be heard as an even louder sound due to the earplug bone conduction effect. In the state in which the earplug bone conduction effect is created, the adding of the waveform inversion signal from the microphone or other outgoing-talk unit  623  to the signal of one&#39;s own voice, on the basis of the detection of pressure by the cartilage conduction vibration source  825 , is the same as in the seventh embodiment. However, in the ninth embodiment, the cartilage conduction vibration source  825  is sandwiched in between the cartilage conduction output unit  863  and the internal cushioning material  873 , which both are elastic bodies, and therefore, similarly with respect to the eighth embodiment, the state in which the earplug bone conduction effect is created is detected by the strain to the cartilage conduction vibration source  825 , which accompanies the strain to the cartilage conduction output unit  863  due to an increase in the pushing force. 
     The significance of the structure in the ninth embodiment, in which the cartilage conduction vibration source  825  is sandwiched between the cartilage conduction output unit  863  and the internal cushioning material  873 , which are both elastic bodies, lies not only in obtaining a favorable conduction of sound, as described above, but also in counteracting impact on the cartilage conduction vibration source  825 , which is made of a piezoelectric bimorph element. In other words, similarly with respect to the eighth embodiment, configuring the cartilage conduction vibration source  825  so as to be enveloped circumferentially can provide cushioning against impact resulting from the rigid structure of the mobile telephone  801 , and can facilitate implementation in the mobile telephone  801 , which is constantly exposed to being dropped and other risks. The elastic body sandwiching the cartilage conduction vibration source  825  not only functions merely as a cushioning material, but also functions as a configuration for more effectively transmitting the vibration of the cartilage conduction vibration source  825  to the ear as described above, due to the fact that at least the outer elastic body is molded of a material having an acoustic impedance approximating that of ear cartilage. 
     Tenth Embodiment 
       FIG. 19  is a perspective view illustrating a tenth embodiment of the mobile telephone according to an aspect of the present invention. A mobile telephone  901  of the tenth embodiment, similarly with respect to that of the fourth embodiment, is an integrated type with no moving parts, and is configured as a “smartphone,” which has a large-screen display unit  205  provided with GUI functions. There is much in common with the structure thereof, and accordingly corresponding portions have been given like reference numerals as in the fourth embodiment, and a description has been omitted. However, similarly with respect to the fourth embodiment, the “upper part” in the tenth embodiment does not signify a separate upper part, but rather signifies the portion at the top of the integrated structure. 
     A point of difference in the tenth embodiment from the fourth embodiment lies in that a cartilage conduction vibration source  925 , which is made up of a piezoelectric bimorph element or the like, serves as the cartilage conduction vibration source, and also takes on the role of a drive source of the incoming-talk unit for generating sound waves that are transmitted to the tympanic membrane by air conduction. To provide a more specific description, the vibration conductor  227 , similarly with respect to the fourth embodiment, is in contact with the upper part of the cartilage conduction vibration source  925  and is arranged at the upper side of the mobile telephone. Furthermore, a cartilage conduction output unit  963 , which, similarly with respect to the seventh embodiment, is made using a material that has acoustic impedance approximating that of ear cartilage (a silicone rubber; a mixture of a silicone rubber and a butadiene rubber; a natural rubber; or; a structure formed using these varieties of rubber in which air bubbles are sealed), is arranged at the front of the cartilage conduction vibration source  925 . Because the cartilage conduction output unit  963 , as will be described later, serves as an incoming-talk unit for generating sound waves that are transmitted to the tympanic membrane by air conduction, the tenth embodiment has no special setting for the incoming-talk unit  13  as in the fourth embodiment. 
     Due to the configuration described above, first, the vibration of the cartilage conduction vibration source  925  is transmitted laterally by the vibration conductor  227 , causing the two ends  224  and  226  thereof to vibrate, and thus causing either one thereof to come into contact with the tragus allows sound to be heard by cartilage conduction. Also, similarly with respect to the fourth embodiment, the vibration conductor  227  vibrates not only at the right end  224  and left end  226  thereof but rather vibrates as a whole. Accordingly, it is possible in the tenth embodiment as well to transmit audio information regardless of where on the top inner edge of the mobile telephone  901  is contact made with the ear cartilage. Then, the vibration conductor  227  is in contact with the ear cartilage over a broad range and also the cartilage conduction output unit  963  is in contact with the tragus and other ear cartilage, when the mobile telephone  901  is brought up against the ear in such a form that a part of the cartilage conduction output unit  963  comes into the front of the entrance of the external auditory meatus, similarly with respect to an ordinary mobile telephone. Through such contact, sound can be heard by cartilage conduction. Similarly with respect to the fifth embodiment to the ninth embodiment, sound from the exterior of the cartilage conduction output unit  963 , which resonates in accordance with the vibration of the cartilage conduction vibration source  925 , is further transmitted to the tympanic membrane from the external auditory meatus as sound waves. In this manner, the cartilage conduction output unit  963  can function as an incoming-talk unit by air conduction in the ordinary state of use of a mobile telephone. 
     Cartilage conduction conducts differently depending on the magnitude of force pushing on the cartilage; a more effective conduction state can be obtained when the pushing force is increased. This signifies that natural behavior, such as increasing the force pushing the mobile telephone against the ear when it is difficult to hear the incoming-talk unit sound, can be utilized to adjust the volume. Even when such a function is not explained to the user in, for example, the instruction manual, the user can still intuitively understand the function through natural behavior. Configuring the vibration of the cartilage conduction vibration source  925  in the tenth embodiment such that the vibration conductor  227 , which is a rigid body, and the cartilage conduction output unit  963 , which is an elastic body, can both simultaneously be in contact with the ear cartilage is intended to permit more effective volume adjustment primarily through adjusting the force pushing on the vibration conductor  227 , which is a rigid body. 
     The employment of the present invention is not to be limited to the above-described embodiments; other aspects can also benefit from the various above-described advantages of the present invention. For example, a resonator that is appropriate as a speaker other than the material having an acoustic impedance approaching that of ear cartilage can be arranged at the position where the cartilage conduction output unit  963  is arranged, in a case in which the tenth embodiment is configured such that the combination of the cartilage conduction vibration source  925  and the cartilage conduction output unit  963  function as a dedicated incoming-talk unit by air conduction. Such a case is also able to benefit from the features and advantages of the tenth embodiment, in which the cartilage conduction vibration source  925 , which is made up of a piezoelectric bimorph element or the like, serves as the cartilage conduction vibration source, and also serves as a drive source of the incoming-talk unit for generating sound waves that are transmitted to the tympanic membrane by air conduction. 
     Eleventh Embodiment 
       FIG. 20  is a perspective view illustrating an eleventh embodiment of the mobile telephone according to an aspect of the present invention. The mobile telephone  1001  of the eleventh embodiment, similarly with respect to that of the fourth embodiment, is an integrated type with no moving parts, and is configured as a “smartphone,” which has a large-screen display unit  205  provided with GUI functions. There is much in common with the structure thereof, and so corresponding portions have been given like reference numerals as in the fourth embodiment, and a description has been omitted. However, similarly with respect to the fourth embodiment, the “upper part” in the eleventh embodiment does not signify a separate upper part, but rather signifies the portion at the top of the integrated structure. 
     A point of difference in the eleventh embodiment from the fourth embodiment lies in that a right ear vibration unit  1024  and a left ear vibration unit  1026  are provided not to the front of the mobile telephone  1001  but rather to a side surface  1007  and to the side surface of the opposite side, shown without a reference number with relation to the diagrams, respectively (it shall be noted that the right ear vibration unit  1024  and the left ear vibration unit  1026  are arranged in a left-right reversal relative to the fourth embodiment of  FIG. 7 ). In a manner functionally similar to that of the fourth embodiment, the right ear vibration unit  1024  and the left ear vibration unit  1026  in the eleventh embodiment are also configured as the two end parts of the vibration conductor  1027 ; the cartilage conduction vibration source  1025 , which is made up of a piezoelectric bimorph element or the like, is arranged in contact with the lower part of the vibration conductor  1027 , the vibration thereof being transmitted to the vibration conductor  1027 . The vibration of the cartilage conduction vibration source  1025  is thereby transmitted laterally by the vibration conductor  1027 , causing the two ends  1024  and  1026  thereof to vibrate. The two ends  1024  and  1026  of the vibration conductor  1027  are provided so as to be in contact with the tragus when the upper end portion of a side surface (for example,  1007 ) of the mobile telephone  1001  is brought up against the ear. 
     A microphone or other outgoing-talk unit  1023  is provided to the lower surface of a mobile telephone  1001  such that audio uttered by the user can be picked up even in the state in which either of the right ear vibration unit  1024  or the left ear vibration unit  1026  is brought up against the tragus. In addition, the mobile telephone  1001  of the eleventh embodiment is provided with a speaker  1013  for videoconferencing functions occurring while the large-screen display unit  205  is being observed; the sensitivity of the microphone or other outgoing-talk unit  1023  is switched at the time of the videoconferencing function, and audio uttered by the user during the observation of the display monitor  205  can be picked up. 
       FIG. 21  is a side view of the mobile telephone  1001  illustrating the function of the right ear vibration unit  1024  and the left ear vibration unit  1026 ; the method illustrated is in accordance with  FIG. 2 . However, as depicted in  FIG. 20 , the right ear vibration unit  1024  and the left ear vibration unit  1026  in the eleventh embodiment are each provided to a side surface of the mobile telephone  1001 . Accordingly, in the eleventh embodiment, the side surface of the mobile telephone  1001  is brought up against the tragus, as depicted in  FIG. 21 , when the mobile telephone  1001  is brought up against the ear. In other words, it is not that the surface of the display unit  5  of the mobile telephone  1  is brought up against the tragus, as in  FIG. 2 ; therefore, the large-screen display unit  205  is not brought up against the ear and/or cheek and will not be fouled by sebum or the like. 
     More specifically,  FIG. 21A  illustrates the state in which the mobile telephone  1001  is held in the right hand and is brought up against the tragus  32  of the right ear  28 ; the side surface in view is the side opposite to the one in the mobile telephone  1001  being brought up against the right ear  28 , and the surface of the large-screen display unit  205  depicted by the cross-section is approximately perpendicular to the cheek and faces the lower rear of the face. The result is that, as described above, the large-screen display unit  205  is not brought up against the ear and/or cheek and does not get fouled with sebum or the like. Similarly,  FIG. 21B  illustrates the state in which the mobile telephone  1001  is held in the left hand and is brought up against the tragus  34  of the left ear  30 ; such a case is also similar to that of  FIG. 21A  in that, the large-screen display unit  205  being approximately perpendicular to the cheek and facing the lower rear of the face, the large-screen display unit  205  is not brought up against the ear and/or cheek and does not get fouled with sebum or the like. 
     However, such a state of use as in  FIG. 21  is implemented from the state in which the mobile telephone  1001  is held with the right hand and the large-screen display unit  205  is observed, for example, in the case of  FIG. 21A , by moving the mobile telephone  1001  without shaking the hand, and bringing the right ear vibration unit  1024  up against the tragus  32 . Accordingly, transitioning between the state of observing the large-screen display unit  205  and the state in which the right ear vibration unit  1024  is brought up against the tragus  32  is possible by a natural movement of the right hand, such as by slightly altering the angle between the elbow and the wrist, without needing to switch the hand holding the mobile telephone  1001  nor to shake the hand. To simplify the above description, the state in  FIG. 21  has the large-screen display unit  205  substantially perpendicular to the cheek, but the user can unrestrictedly select the angle of the hand or the posture for bringing the mobile telephone  1001  up against the ear; the angle of the large-screen display unit  205  with the cheek therefore need not be perpendicular, but rather may be moderately inclined. However, because each of the right ear vibration unit  1024  and the left ear vibration unit  1026  is provided to a side surface of the mobile telephone  1001  according to the configuration of the eleventh embodiment, the large-screen display unit  205  is not brought up against the ear and/or cheek and will not be fouled by sebum or the like, regardless of the posture in which the vibration units are brought up against the tragus  32  or  34 . 
     As a result of the fact that the large-screen display unit  205  is not hidden by facing the direction of the cheek in the eleventh embodiment, it is possible that the call destination or other display content may be seen by other people in front or rear. Accordingly, to protect privacy in the eleventh embodiment, a switch is automatically made from an ordinary display to a privacy-protection display (where, for example, nothing is displayed) in the state in which the right ear vibration unit  1024  or the left ear vibration unit  1026  is brought up against the ear. This point will be described in greater detail later. 
     Twelfth Embodiment 
       FIG. 22  is a perspective view illustrating a twelfth embodiment of the mobile telephone according to an aspect of the present invention.  FIG. 22A  illustrates the state in which a handle  1181  (to be described later) does not project out, and  FIG. 22B  illustrates the state in which the handle  1181  does project out. Similarly with respect to the eleventh embodiment, s cartilage conduction vibration unit  1124  of a mobile telephone  1101  of the twelfth embodiment is provided to a side surface of the mobile telephone  1101  (the side surface of the left side seen in  FIG. 22 , there being no reference numeral assigned thereto because the surface is hidden for convenience of illustration). The twelfth embodiment, being a mobile telephone, is based on an integrated type with no movable parts that is similar to the eleventh embodiment, and is configured as a “smartphone” having a large-screen display unit  205  provided with GUI functions. There is much in common with the structure thereof, and so corresponding portions have been given like reference numerals as in the eleventh embodiment, and a description has been omitted. However, similarly with respect to the eleventh embodiment, the “upper part” in the twelfth embodiment does not signify a separate upper part, but rather signifies the portion at the top of the integrated structure. 
     A point of difference in the twelfth embodiment from the eleventh embodiment lies in that, in addition to the configuration of the handle  1181  (to be described later), the cartilage conduction vibration unit  1124  is provided to one side surface on the left seen from  FIG. 22  in the mobile telephone  1101 . The element that is to be brought up against the ear is limited to being on the side surface of the left side, and therefore a microphone or other outgoing-talk unit  1123  is also provided to the lower surface close to the left side surface of the mobile telephone  1101 , as illustrated in  FIG. 22 . However, in the twelfth embodiment as well, the outgoing-talk unit  1123  is switched at the time of a videoconferencing function occurring while the large-screen display unit  205  is being observed, and audio uttered by the user as they observe the large-screen display unit  205  can be picked up. 
     In the twelfth embodiment, similarly with respect to the eleventh embodiment, the cartilage conduction vibration unit  1124  can be brought up against the tragus of the right ear from the state in which the large-screen display unit  205  is being viewed, as in  FIG. 22 . On the other hand, to bring the cartilage conduction vibration unit  1124  up against the tragus of the left ear, the holding hand can be switched such that the mobile telephone  1101  faces backwards, the cartilage conduction vibration unit  1124  thereby being made to face the left ear. Use in such a manner is also possible in the state in which the handle  1181  does not project out, as in  FIG. 22A . 
     The following is a description of the function of the handle. One natural way of holding when the cartilage conduction vibration unit  1124  is brought up against the ear at such an angle that the large-screen display unit  205  is approximately perpendicular to the cheek, as in  FIG. 21 , is embodied in a form such that the front surface of the mobile telephone  1101  on which the large-screen display unit  205  is provided and the back surface thereof are sandwiched by the thumb and the other four fingers, but the fingers at this time are in a state of touching the large-screen display unit  205 ; therefore, a concern is presented in that a mistaken operation is possible and the comparatively long-term and powerful contact during a call will result in fingerprint fouling. 
     In view whereof, to prevent the fingers from touching the large-screen display unit  205  while also facilitating holding the mobile telephone  1101 , the twelfth embodiment is configured such that the handle  1181  projects out from the state in  FIG. 22A  to the state in  FIG. 22B  according to need, it being possible to use the handle  1181  to hold the mobile telephone. It thereby becomes possible in the state represented in  FIG. 22B  to sandwich the handle  1181  and the end parts of the body of the mobile telephone  1101  with the thumb and the other four fingers, and the mobile telephone  1101  can be readily held without the large-screen display unit  205  being touched. The handle  1181  can also be grasped to hold the mobile telephone  1101  in a case in which the degree of projection is configured so as to be comparatively larger. However, similarly with respect to the case of the state in  FIG. 22A , the mobile telephone  1101  can also be held so as to face backwards, the cartilage conduction vibration unit  1124  thereby being brought up against the tragus of the left ear. 
     To cause the handle  1181  to project out from the state in  FIG. 22A , a projection operation button  1183  is pushed and the handle is thereby unlocked and projects slightly outward; the state in  FIG. 22B  can therefore be achieved by pulling the handle out. Because the lock is engaged in the state in  FIG. 22B , no problems are presented even when the handle  1181  is held and the cartilage conduction vibration unit  1124  is pushed up against the tragus. To house the handle  1181 , the lock is undone when the projection operation button  1183  is pushed in the state in  FIG. 22B ; therefore, the lock is engaged when the handle  1181  is pushed in so as to assume the state in  FIG. 22A . 
       FIG. 23  is a flow chart of the operation of the controller  239  (borrowing from  FIG. 8 ) in the twelfth embodiment of  FIG. 22 . However, parts that the flow of  FIG. 23  shares with the flow of  FIG. 14  have been given like step reference numerals, and a description thereof has been omitted.  FIG. 23  also illustrates an abstraction of the operation that focuses on related functions, in order to primarily provide a description of the function of the cartilage conduction vibration unit  228 . Accordingly, similarly with respect to  FIG. 14  and the like, the controller  239  in the twelfth embodiment also contains typical mobile telephone functions and other operations not represented by the flow of  FIG. 23 .  FIG. 23  uses boldface print to illustrate points of difference with  FIG. 14 , and thus the following description focuses on these portions. 
     In the flow of  FIG. 23 , there is performed a check for whether there has been an operation to initiate a call once step S 104  is reached. A case in which there has not been an operation moves directly on to step S 34 . On the other hand, in a case in which an operation to initiate a call is detected, the flow proceeds to step S 132 , in which there is performed a check for whether the handle  1181  is in state of projecting. Then, in a case of the handle not being in a state of projecting out, the flow proceeds to step S 134 , in which there is performed a check for whether the cartilage conduction vibration unit  1124  is in a state of being in contact with the ear cartilage. Then, in a case in which a state of contact is detected, the flow proceeds to step S 136 . However, in a case in which it is detected in step S 132  that the handle  1181  is in a state of projecting out, the flow moves directly on to step S 136 . 
     In step S 136 , the outgoing-talk unit  1123  is turned on, and in step S 138 , the cartilage conduction vibration unit  1124  is turned on. On the other hand, the speaker  1013  is turned off in step S 140 . Subsequently, proceeding on to step S 142 , the display of the large-screen display unit  205  is set to a privacy-protection display. The privacy-protection display is a state in which either there is a predetermined display that does not contain private information, or nothing is displayed at all. At this point in time, only the display content is altered, without the large-screen display unit  205  itself being turned off. After the display has been controlled in such a manner, the flow moves on to step S 52 . A case in which the desired state already exists in step S 136  to S 142  leads to step S 52  without anything being done in these steps as a result. 
     On the other hand, in a case in which there is no detection in step S 134  that the cartilage conduction vibration unit  1124  is in a state of being in contact with the ear cartilage, the flow moves on to step S 144 , which turns the outgoing-talk unit  1123  on; in step S 146 , the cartilage conduction vibration unit  1124  is turned off. Meanwhile, the speaker  1013  is turned on in step S 148 . Subsequently, the flow proceeds to step S 150 , and the display of the large-screen display unit  205  is set to an ordinary display. After the display has been controlled in such a manner, the flow moves on to step S 118 . A case in which the desired state already exists in step S 144  to S 150  also leads to step S 118 , without anything being done in these steps as a result. 
     Steps S 52  to S 56 , step S 118 , and step S 34 , which follow step S 142 ; as well as step S 118  and step S 34 , which follow step S 150 , are shared with  FIG. 14 , and a description thereof has thereof been omitted. Upon moving on to step S 118 , there is performed a check for whether the call state has been cut off; in a case in which no call state interruption is detected, the flow returns to step S 132 , following which steps S 132  to S 150  and steps S 52  to S 56  are repeated. Switching between the cartilage conduction vibration unit  1124  and the speaker  1013  and also switching the display are thereby performed automatically, either by moving the handle  1181  in or out or by the contact or non-contact of the cartilage conduction vibration unit  1124 . In the state in which the cartilage conduction vibration unit  1124  has been turned on, switching occurs automatically between whether or not the waveform inversion signal of one&#39;s own voice is added, which is based on the presence or absence of the earplug bone conduction effect. 
     In the repetition of the aforementioned steps, there may be an insertion in between steps S 142  and S 52  of a step for determining whether a predetermined period of time has passed after the display of the large-screen display unit  205  is initially changed to the privacy-protection display in step S 142 , and also of a step for turning the large-screen display unit  205  itself off with the purpose of saving electricity when the predetermined period of time has passed. At this time, in accordance therewith, there is an insertion in between steps S 148  and S 150  of a step for turning the large-screen display unit  205  on when same has been turned off. The flow in  FIG. 23  can also be used for the eleventh embodiment in  FIG. 20  by the omission of step S 132 . 
     Thirteenth Embodiment 
       FIG. 24  is a perspective view illustrating a thirteenth embodiment of the mobile telephone according to an aspect of the present invention.  FIG. 24A  illustrates a state in which an incoming/outgoing-talk unit  1281  (to be described later) is integrated with a mobile telephone  1201 , and  FIG. 24B  illustrates a state in which the incoming/outgoing-talk unit  1281  is separated. The mobile telephone  1201  of the thirteenth embodiment assumes a state in which a cartilage conduction vibration unit  1226  is arranged on the side surface  1007  of the mobile telephone  1201  in the state in  FIG. 24A . This is a point of similarity with the eleventh and twelfth embodiments. The thirteenth embodiment, being a mobile telephone, is based on an integrated type with no movable parts that is similar to the eleventh embodiment and the twelfth embodiment, and is configured as a “smartphone” having a large-screen display unit  205  provided with GUI functions. There is much in common with the structure thereof, and so corresponding portions have been given like reference numerals as in the twelfth embodiment, and a description has been omitted. However, similarly with respect to the eleventh embodiment and the twelfth embodiment, the “upper part” in the thirteenth embodiment does not signify a separate upper part, but rather signifies the portion at the top of the integrated structure. 
     The thirteenth embodiment has a similar configuration to that of  FIG. 22A  of the twelfth embodiment, except in that, in the state in  FIG. 24A , the cartilage conduction vibration unit  1226  and an outgoing-talk unit  1223  are arranged on the right when seen from  FIG. 24 . However, the cartilage conduction vibration unit  1226  is brought up against the tragus of the left ear from the state in which the large-screen display unit  205  is being viewed, as in  FIG. 24 . Then, to bring the cartilage conduction vibration unit  1226  up against the tragus of the right ear, the holding hand is switched such that the mobile telephone  1201  faces backwards, whereby the cartilage conduction vibration unit  1226  is made to face the left ear. 
     A point of difference in the thirteenth embodiment from the twelfth embodiment lies in that the incoming/outgoing-talk unit  1281 , which comprises the cartilage conduction vibration unit  1226  and the outgoing-talk unit  1223 , can be separated from the mobile telephone  1201 , as in  FIG. 24B . The incoming/outgoing-talk unit  1281  can be inserted into and released from the mobile telephone  1201  by the operation of an insertion/release locking button  1283 . The incoming/outgoing-talk unit  1281  further possesses an incoming/outgoing-talk operation unit  1209 , and also a controller  1239  for the cartilage conduction vibration unit  1226  and the outgoing-talk unit  1223 , the controller comprising a power supply unit. The incoming/outgoing-talk unit  1281  also possesses a Bluetooth™ or other short-range communication unit  1287 , which is capable of wireless communication with the mobile telephone  1201  using radio waves  1285 ; the user&#39;s voice, which is picked up from the outgoing-talk unit  1223 , and also information on the state of the contact of the cartilage conduction vibration unit  1226  with the ear are sent to the mobile telephone  1201 , and the cartilage conduction vibration unit  1226  vibrates on the basis of the audio information received from the mobile telephone  1201 . 
     The incoming/outgoing-talk unit  1281  separated out in the manner described above functions as a pencil incoming/outgoing-talk unit; the cartilage conduction vibration unit  1226  is held unrestrictedly and brought into contact with the tragus of either the right ear or the left ear, whereby a call can take place. Increasing the contact pressure on the tragus can yield the ear plug bone conduction effect. The incoming/outgoing-talk unit  1281  being in the separated state, sound can be heard by air conduction even when either the surface around the long axis of the cartilage conduction vibration unit  1226  or the tip thereof is brought up against the ear. In addition to the method for using the incoming/outgoing-talk unit  1281 , in which the incoming/outgoing-talk unit ordinarily is housed in the mobile telephone  1201  as in  FIG. 24A  and is then separated out as appropriate like in  FIG. 24B , there is also a possible method for using the incoming/outgoing-talk unit such that, in the separated state as in  FIG. 24B , for example, the mobile telephone  1201  being housed in an inner pocket or bag and the incoming/outgoing-talk unit  1281  being inserted into an outer breast pocket like a pencil, only the incoming/outgoing-talk unit  1281  is used for operation and for calls to take place when outgoing and incoming calls are made. The cartilage conduction vibration unit  1226  can also function as a vibrator for incoming calls. 
     A pencil incoming/outgoing-talk unit  1281  such as in the thirteenth embodiment is not to be limited to the case of comprising a combination with a specialized mobile telephone  1201  having a housing unit. For example, a configuration as an accessory of a typical mobile telephone having a short-range communication function using Bluetooth™ or the like is also possible. 
     Fourteenth Embodiment 
       FIG. 25  is a perspective view illustrating a fourteenth embodiment of the mobile telephone according to an aspect of the present invention.  FIG. 25A  illustrates the state in which an incoming/outgoing-talk unit  1381  (to be described later) is housed in a mobile telephone  1301 , and  FIG. 25B  illustrates the state in which the incoming/outgoing-talk unit  1381  is pulled out. The mobile telephone  1301  of the fourteenth embodiment assumes a state in which a cartilage conduction vibration unit  1326  is arranged on the side surface  1007  of the mobile telephone  1301  in the state in  FIG. 25A . This is a point of similarity with the eleventh to thirteenth embodiments. The fourteenth embodiment, being a mobile telephone, is based on an integrated type with no movable parts that is similar to the eleventh to thirteenth embodiments, and is configured as a “smartphone” having a large-screen display unit  205  provided with GUI functions. There is much in common with the structure thereof, and so corresponding portions have been given like reference numerals as in the thirteenth embodiment, and a description has been omitted. However, similarly with respect to the eleventh to thirteenth embodiments, the “upper part” in the fourteenth embodiment does not signify a separate upper part, but rather signifies the portion at the top of the integrated structure. 
     The fourteenth embodiment, in the state in  FIG. 25A , also has a similar configuration to that of  FIG. 24A  of the thirteenth embodiment. A point of difference in the fourteenth embodiment from the thirteenth embodiment lies in that, as illustrated in  FIG. 25B , the incoming/outgoing-talk unit  1381  has a wired connection with the mobile telephone  1301  rather than a wireless one. Similarly with respect to the thirteenth embodiment, the incoming/outgoing-talk unit  1381  can be inserted into and released from the mobile telephone  1301  by the operation of the insertion/release locking button  1283 . The incoming/outgoing-talk unit  1381  has a cable  1339  for respectively connecting the cartilage conduction vibration unit  1326  with the outgoing-talk unit  1323 , and also the outgoing-talk unit  1323  with the mobile telephone  1301 . In the housed state in  FIG. 25A , the portion of the cable  1339  that is between the cartilage conduction vibration unit  1326  and the outgoing-talk unit  1323  is housed in a groove of the side surface  1007 , and the portion thereof that is between the outgoing-talk unit  1323  and the mobile telephone  1301  is automatically wound up within the mobile telephone  1301  by a spring when the outgoing-talk unit  1323  is housed. The outgoing-talk unit  1323  is also provided with a remote control operation unit for operating at the time of outgoing and incoming calls. In the manner described above, in the fourteenth embodiment, the user&#39;s voice, which is picked up from the outgoing-talk unit  1323 , and also information on the state of the contact of the cartilage conduction vibration unit  1326  with the ear are transmitted to the mobile telephone  1301  by wire, and the cartilage conduction vibration unit  1326  vibrates on the basis of the audio information received by wire from the mobile telephone  1301 . 
     The incoming/outgoing-talk unit  1381  pulled out as in  FIG. 25B  is used by being hooked onto the cartilage of the lower part of the entrance to the external auditory meatus such that the portion of the cartilage conduction vibration unit  1326  is in contact with the tragus. Then, the outgoing-talk unit  1323  in this state is located close to the mouth, and can therefore pick up the user&#39;s voice. Holding the portion of the cartilage conduction vibration unit  1326  and increasing the contact pressure on the tragus can yield the ear plug bone conduction effect. In addition to the method for using the incoming/outgoing-talk unit  1381  in which the incoming/outgoing-talk unit ordinarily is housed in the mobile telephone  1301  as in  FIG. 25A  and is then pulled out as appropriate like in  FIG. 25B , there is also a possible method for using the incoming/outgoing-talk unit such that, in the state in which the incoming/outgoing-talk unit  1381  is pulled out as in  FIG. 25B , for example, the mobile telephone  1301  remains housed in an inner pocket or the like and the cartilage conduction vibration unit  1326  of the incoming/outgoing-talk unit  1381  remains hooked on the ear. The cartilage conduction vibration unit  1326  can also function as a vibrator for incoming calls, similarly with respect to the thirteenth embodiment. 
     A wired earphone-type incoming/outgoing-talk unit  1381  such as in the fourteenth embodiment is not to be limited to the case of comprising a combination with a specialized mobile telephone  1301  having a housing unit. For example, a configuration as an accessory of a typical mobile telephone having an external earphone-microphone connection terminal is also possible. 
     The various features indicated in each of the embodiments described above are not necessarily specific in each case to an individual embodiment; the features of each of the embodiments can be combined or rearranged with the features of other embodiments as appropriate, wherever it is possible to make use of the advantages thereof. 
     The implementation of the variety of features indicated in each of the embodiments described above is not to be limited to the above embodiments; the features can be implemented in other embodiments as well, wherever it is possible to benefit from the advantages thereof. For example, arranging the cartilage conduction vibration unit on the side surface relative to the display surface in the eleventh to fourteenth embodiments, being a configuration in which audio information is transmitted from the tragus by cartilage conduction, can thereby facilitate contact with the tragus and use the tragus as a conduction point for sound information. It is accordingly possible to achieve a listening posture free of discomfort, and approximating that of a conventional telephone in which one listens using the ear. The transmission of audio by cartilage conduction also does not require the formation of a closed space at the front of the entrance to the external auditory meatus, as is the case with air conduction, and is therefore appropriate for arrangement on the side surface. Furthermore, because audio information is conducted by cartilage conduction, there is a low percentage of air conduction caused by the vibration of the vibrator, and sound can be transmitted to the user&#39;s external auditory meatus without substantial sound leakage to the exterior, even though the cartilage conduction vibration unit is arranged on the side surface of the mobile telephone, which is narrow. This is due to the fact that, in cartilage conduction, sound does not enter the external auditory meatus as air conduction sound but rather is transmitted due to the contact of the sound energy with the cartilage, the sound being generated thereafter inside the external auditory meatus by the vibration of the tissue in the ear. Accordingly, the utilization of the cartilage conduction vibration unit in the eleventh to fourteenth embodiments is also very effective when a sound information output unit is arranged on the side surface relative to the display surface, there being no concern that the incoming-talk unit sound will be heard by neighboring people due to sound leakage, which would be annoying, nor that any sensitive information will be leaked. 
     However, from the standpoint of benefiting from the advantage of being able to prevent the display surface from being fouled by contact with the ear and/or cheek when audio information is being listened to, the arrangement on the side surface relative to the display surface is not to be limited to a case in which the audio information output unit that is to be arranged is the cartilage conduction vibration unit. For example, the configuration may be such that the audio information output unit is an earphone that works by air conduction, the earphone being provided to the side surface relative to the display surface. The configuration may also be such that the audio information output unit is a bone conduction vibration unit hitting against a bone at the front of the ear (the zygomatic arch), a bone at the rear of the ear (the mastoid part), or the forehead, the unit being arranged on the side surface relative to the display surface. Due to the arrangement on the side surface relative to the display surface, the display surface will not be in contact with the ear and/or cheek when audio information is being listened to; therefore, even in cases where these audio information output units are used, advantages can also accrue in regard to being able to prevent fouling of the display surface. In cases in which such units are used, moreover, a microphone can be arranged on the side surface relative to the display surface in a case in which the arrangement of the earphone and/or bone conduction vibration unit is limited to one side surface, as in the twelfth to fourteenth embodiments. Similarly with respect to the eleventh to fourteenth embodiments, when the earphone is brought up against the ear for a call in a posture such as is represented in  FIG. 21 , or, alternatively, when the bone conduction vibration unit is held to a bone at the front or rear of the ear for a call, setting the display surface to a privacy-protection display makes it possible to prevent a display containing private information from being viewed by other people, either in the front or rear or to the left or right. 
     Fifteenth Embodiment 
       FIG. 26  is a diagram of the system of a fifteenth embodiment according to an aspect of the present invention. The fifteenth embodiment is configured as an incoming/outgoing-talk unit for a mobile telephone, and forms a mobile telephone system together with a mobile telephone  1401 . The fifteenth embodiment takes the configuration of a system in common with the configuration of the system in the state in which the incoming/outgoing-talk unit  1281  is separated from the mobile telephone  1201 , as in  FIG. 24B  in the thirteenth embodiment; therefore, portions that are in common have been given like reference numerals, a description thereof being omitted unless there is a particular need. The mobile telephone  1401 , similarly with respect to the mobile telephone  1201  of the thirteenth embodiment, is not to be limited to the case of being specially configured to be used in combination with an incoming/outgoing-talk unit; rather, the case may also be one of a configuration as a typical mobile telephone having, for example, a short-range communication function using Bluetooth™ or the like. The incoming/outgoing-talk unit in such a case then assumes a configuration as an accessory of such a typical mobile telephone  1401 , similarly with respect to the thirteenth embodiment. A more detailed description of these two cases will be provided later. 
     A point of difference in the fifteenth embodiment from the thirteenth embodiment lies in that the incoming/outgoing-talk unit is configured as a headset  1481 , rather than in a pencil-type format such as in the thirteenth embodiment. The incoming/outgoing-talk unit  1481  conforms with the thirteenth embodiment in being provided with an outgoing-talk unit  1423  and a cartilage conduction vibration unit  1426  comprising a piezoelectric bimorph element; in being provided with a controller  1439 , which comprises a power supply unit for the cartilage conduction vibration unit  1426  and the outgoing-talk unit  1423 ; and in being provided with the incoming/outgoing-talk operation unit  1409 . The incoming/outgoing-talk unit  1481  further conforms with the thirteenth embodiment in being provided a short-range communication unit  1487  compliant with Bluetooth™ or another scheme and capable of wireless communication with the mobile telephone  1401  using radio waves  1285 ; in sending to the mobile telephone  1401  the user&#39;s voice, which is picked up from the outgoing-talk unit  1423 , and also information on the state of the contact made by the cartilage conduction vibration unit  1426  with the ear; and in causing the cartilage conduction vibration unit  1426  to vibrate on the basis of the audio information received from the mobile telephone  1401 . 
     There shall next be provided a description of the configuration specific to the fifteenth embodiment. The headset  1481  is attached to the right ear  28  by an ear-hooking unit  1489 . The headset  1481  is provided with a movable unit  1491  that is held by an elastic body  1473 , and the cartilage conduction vibration unit  1426  is held by the movable unit  1491 . The configuration is such that the cartilage conduction vibration unit  1426  is in contact with the tragus  32  in the state in which the headset  1481  is attached to the right ear  28  by the ear-hooking unit  1489 . The elastic body  1473  makes it possible to bend the movable unit  1491  in the direction of the tragus  32 , and also functions as a cushioning material for the cartilage conduction vibration unit  1426 , protecting the cartilage conduction vibration unit  1426  against mechanical impact due to the headset  1481 . 
     Sound information can be listened to via ordinary cartilage conduction in the state in  FIG. 26 . However, when listening comprehension of sound information is impaired due to environment noise, the movable unit  1491  is pushed from the exterior and thereby bent, and the pressure contact of the cartilage conduction vibration unit  1426  on the tragus  32  is increased, whereby the tragus  32  is made to block the hole of the ear. The ear plug conduction effect, which has also been described in the other embodiments, can thereby be generated, and even louder audio information can be transmitted. Obstructing the hole of the ear with the tragus  32  further allows environment noise to be blocked. Information on one&#39;s own voice, which is picked up from the outgoing-talk unit  1423 , is also subjected to phase inversion on the basis of the mechanical detection of the bent state of the movable unit  1491 , and is then transmitted to the cartilage conduction vibration unit  1426 , to cancel out one&#39;s own voice. A more detailed description of the merits or other advantageous attributes thereof has been described in the other embodiments, and thus has been omitted. 
     Sixteenth Embodiment 
       FIG. 27  is a diagram of the system of a sixteenth embodiment according to an aspect of the present invention. The sixteenth embodiment is also configured as a headset  1581  for creating an incoming/outgoing-talk unit for the mobile telephone  1401 , similarly with respect to the fifteenth embodiment, and forms a mobile telephone system together with the mobile telephone  1401 . The sixteenth embodiment has much in common with the fifteenth embodiment, and therefore parts that are in common have been given like reference numerals, and a description thereof has been omitted unless there is a particular need. The mobile telephone  1401 , as has been described in the fifteenth embodiment, may in some cases have a special configuration, and may in other cases be configured as a typical mobile telephone. A description of these two cases will be provided later. 
     A point of difference in the sixteenth embodiment from the fifteenth embodiment lies in that the entirety of a movable unit  1591  is made using an elastic material that has acoustic impedance approximating that of ear cartilage (a silicone rubber; a mixture of a silicone rubber and a butadiene rubber; a natural rubber; or a structure formed using these varieties of rubber in which air bubbles are sealed). A cartilage conduction vibration unit  1526 , which comprises a piezoelectric bimorph element or the like, is embedded inside the movable unit  1591 , similarly with respect to the eighth embodiment. Such a configuration allows the movable unit  1591 , including the cartilage conduction vibration unit  1526 , to be bent toward the tragus  32  under its own elasticity. Although omitted from the diagrams for simplicity, the circuit portions of the cartilage conduction vibration unit  1526 , the controller  1439 , and the like are connected by a connection wire similar to the flexible connection wire  769  in  FIG. 17C . 
     In the sixteenth embodiment, the movable unit  1591  is in contact with the tragus  32  in the state represented in  FIG. 27 ; sound information from the cartilage conduction vibration unit  1526  is conducted to the tragus  32  by cartilage conduction via the elastic material of the moveable unit  1591 . The benefits from such a configuration are similar to those described in the fifth to tenth embodiments. Furthermore, when listening comprehension of sound information is impaired due to environment noise, the movable unit  1591  is pushed from the exterior and thereby bent, and the pressure contact of the cartilage conduction vibration unit  1526  on the tragus  32  is increased, whereby the tragus  32  is made to block the hole of the ear. The ear plug conduction effect can thereby be generated, and even louder sound information can thereby be transmitted, similarly with respect to the fifteenth embodiment. The fact that environment noise can be blocked by the obstruction of the hole of the ear by the tragus  32  is also similar to the fifteenth embodiment. Another similarity with the fifteenth embodiment is the fact that information on one&#39;s own voice, which is picked up from the outgoing-talk unit  1423 , can also be subjected to phase inversion on the basis of the mechanical detection of the bent state of the movable unit  1591  and then transmitted to the cartilage conduction vibration unit  1526  to cancel out one&#39;s own voice. 
     Furthermore, in the sixteenth embodiment, because the cartilage conduction vibration unit  1526  is embedded inside the movable unit  1591 , the elastic material constituting the movable unit  1591  functions as a cushioning material for protecting the cartilage conduction vibration unit  1526  against mechanical impact to the headset  1581  and also for further protecting the cartilage conduction vibration unit  1526  against mechanical impact to the movable unit  1591  itself. 
       FIG. 28  is a block diagram of the sixteenth embodiment, identical portions being given identical reference numerals to those in  FIG. 27 . Also, because the configuration of the block diagram has many portions in common with the fourth embodiment, corresponding portions are each assigned the same reference numerals as each respective part. Also, a description has been omitted for these identical or shared portions, unless there is a particular need. In the sixteenth embodiment, the incoming-talk-processing unit  212  and the earphone  213  in  FIG. 28  correspond to the incoming-talk unit  13  in  FIG. 27 , and the outgoing-talk-processing unit  222  and the microphone  223  in  FIG. 28  correspond to the outgoing-talk unit  23  in  FIG. 27 . Similarly with respect to the fourth embodiment, the outgoing-talk-processing unit  222  transmits a part of the audio from the operator picked up by the microphone  223  to the incoming-talk-processing unit  212  as sidetone, and the incoming-talk-processing unit  212  superimposes the operator&#39;s own sidetone onto the voice of the calling party from the telephone communication unit  47  and outputs same to the earphone  213 , whereby the balance between the bone conduction and air conduction of one&#39;s own voice in the state in which the mobile telephone  1401  is brought up against an ear is made to approximate a natural state. 
     A point of difference in the block diagram of the sixteenth embodiment in  FIG. 28  from the block diagram of the fourth embodiment in  FIG. 8  lies in that the mobile telephone  301  of the fourth embodiment in  FIG. 8  is divided in the sixteenth embodiment of  FIG. 28  into the mobile telephone  1401  and the headset  1581  for creating the incoming/outgoing-talk unit. Specifically,  FIG. 28  corresponds to a block diagram of the case in the sixteenth embodiment in which the mobile telephone  1401  is specially configured to be used in combination with the headset  1581 . 
     More specifically, in  FIG. 28 , the output of the phase adjustment mixer unit  236  is wirelessly sent externally by a short-range communication unit  1446  using Bluetooth™ or the like. The short-range communication unit  1446  also inputs audio signals received wirelessly from an external microphone into the outgoing-talk-processing unit  222 . Furthermore, although a depiction and description has been omitted in the other embodiments,  FIG. 28  depicts a power supply unit  1448 , which has a storage battery for supplying power to the entire mobile telephone  1401 . 
     On the other hand, the configuration of the headset  1581  has a short-range communication unit  1487  for intercommunication with the short-range communication unit  1446  of the mobile telephone  1401  using radio waves  1285 , and also has a power supply unit  1548  for supplying power to the entire headset  1581 . The power supply unit  1548  supplies power by a replaceable battery or by a built-in storage battery. The controller  1439  of the headset  1581  wirelessly sends audio picked up from the outgoing-talk unit (microphone)  1423  to the mobile telephone  1401  from the short-range communication unit  1487 , and also controls the drive of the cartilage conduction vibration unit  1526  on the basis of audio information that has been received by the short-range communication unit  1487 . Furthermore, the controller  1439  transmits an operation to receive an incoming call or to send an outgoing call, which is performed by the operation unit  1409 , to the mobile telephone  1401  from the short-range communication unit  1487 . A bending detection unit  1588  mechanically detects the bent state of the movable unit  1591 , and the controller  1439  transmits the bending detection information from the short-range communication unit  1487  to the mobile telephone  1401 . The bending detection unit  1588  can comprise, for example, a switch that is turned on mechanically when the bending reaches or exceeds a predetermined angle. The controller  239  of the mobile telephone  1401  controls the phase adjustment mixer unit  236  on the basis of the bending detection information received by the short-range communication unit  1446 , and determines whether or not to add, to the audio information from the incoming-talk-processing unit  212 , the signal of the waveform inverter  240  that is based on one&#39;s own voice transmitted from the outgoing-talk unit (microphone)  1423  to the outgoing-talk-processing unit  222 . 
     Seventeenth Embodiment 
       FIG. 29  is a block diagram of the case in which, in the sixteenth embodiment of  FIG. 27 , the mobile telephone  1401  is configured as a typical mobile telephone, and the headset  158  is configured as an accessory thereof; the diagram serves to provide a description as the seventeenth embodiment in order to avoid confusion with  FIG. 28 . The configuration of  FIG. 29  has much in common with  FIG. 28 , and therefore identical parts have been given reference numerals identical to those in  FIG. 28 , a description thereof having been omitted unless there is a particular need. 
     As described above, the mobile telephone  1601  in the seventeenth embodiment in  FIG. 29  is configured as a typical mobile telephone comprising a short-range communication function using Bluetooth™ or the like. Specifically, the short-range communication unit  1446  inputs to the outgoing-talk-processing unit  222  audio information from an external microphone that is similar to what is inputted from the microphone  223 , and also externally outputs audio information that is similar to what is outputted to the earphone  213 . The controller  239  is used to switch the audio information that is inputted from and outputted to external elements through the short-range communication unit  1446  relative to the internal microphone  223  and earphone  213 . As described above, in the seventeenth embodiment of  FIG. 29 , the functions of the acoustics adjustment unit  238 , the waveform inverter  240 , and the phase adjustment mixer unit  236  in the sixteenth embodiment in  FIG. 28  are transferred to the headset  1681 . 
     In accordance therewith, the configuration of the headset  1681  in the seventeenth embodiment of  FIG. 29  differs from that of the sixteenth embodiment in  FIG. 28  on the following points. The configuration is such that, although listening audio information received using the short-range communication unit  1487  by the control of a controller  1639  of the headset  1681  is inputted to the phase adjustment mixer unit  1636 , audio information from the waveform inverter  1640  can also additionally be inputted thereto. Also, according to need, the phase adjustment mixer unit  1636  mixes the audio information from the waveform inverter  1640  into the received listening audio information and drives a cartilage conduction vibration unit  1626 . More specifically, a part of the audio from the operator that has been picked up by the outgoing-talk unit (microphone)  1423  is inputted to the acoustics adjustment unit  1638 , and the acoustics of one&#39;s own voice to be transmitted to the cochlea from a cartilage conduction vibration unit  1628 , which comprises the cartilage conduction vibration unit  1626 , are adjusted to acoustics approximating the operator&#39;s own voice transmitted to the cochlea by conduction in the body from the vocal cords when the ear plug bone conduction effect is generated, and the two are effectively canceled out. The waveform inverter  1640  subjects one&#39;s own voice, which has undergone acoustic adjustment in this manner, to waveform inversion, and outputs the same according to need to the phase adjustment mixer unit  1636 . 
     The mixing control shall now be described in detail. When the bending of the movable unit  1591  detected by the bending detection unit  1588  reaches or exceeds a predetermined angle and a state is in effect in which the hole of the ear is obstructed by the tragus, which is pushed thereby, the phase adjustment mixer unit  1636  mixes the output from the waveform inverter  1640  and drives the cartilage conduction vibration unit  1628 , depending on an instruction from the controller  1639 . The excessive amount of one&#39;s own voice that occurs during the earplug bone conduction effect is thereby cancelled out, thus easing the discomfort. At this time, the degree of cancellation is regulated such that an amount of one&#39;s own voice equivalent to the sidetone remains without being cancelled out. On the other hand, when the bending detection unit  1588  does not detect a predetermined or greater amount of bending, the state in effect is one in which the hole of the ear is not obstructed by the tragus and the earplug bone conduction effect is not created; therefore, the phase adjustment mixer unit  1636  does not mix the waveform inversion output of one&#39;s own voice from the waveform inverter  1640 , on the basis of an instruction from the controller  1639 . Similarly with respect to the fourth embodiment, the configuration of the seventeenth embodiment of  FIG. 29  may invert the positions of the acoustics adjustment unit  1638  and the waveform inverter  1640 . Furthermore, the acoustics adjustment unit  1638  and the waveform inverter  1640  may be integrated as a function within the phase adjustment mixer unit  1636 . It is a point of similarity with the sixteenth embodiment that the controller  1639  transmits an operation to receive an incoming call or to send an outgoing call, which is performed by the operation unit  1409 , to the mobile telephone  1601  from the short-range communication unit  1487 . 
     The block diagrams in  FIGS. 28 and 29  can be applied not only to the configuration of the system diagram in  FIG. 27 , but also the system diagram of the fifteenth embodiment in  FIG. 26 . They can also be applied to the thirteenth embodiment of  FIG. 24  and the fourteenth embodiment of  FIG. 25  when the bending detection unit  1588  is read as the pressure sensor  242  as in  FIG. 8 . However, in the case of a reading as the thirteenth embodiment, in the case in which the incoming/outgoing-talk unit  1281  is incorporated into the mobile telephone  1201  as in  FIG. 24A , a contact unit for directly connecting the two is provided to the mobile telephone  1201  and the incoming/outgoing-talk unit  1281 . In the state in  FIG. 24A , the wireless communication exchange between the mobile telephone  1201  and the incoming/outgoing-talk unit  1281  by a short-range communication unit is automatically switched to communication via such a contact unit. In the case of a reading as the fourteenth embodiment, a connector contact for establishing a wired connection between the two is provided to the mobile telephone  1301  and the incoming/outgoing-talk unit  1381  instead of the short-range communication unit. 
       FIG. 30  is a flow chart of the operation of the controller  1639  of the headset  1681  in the seventeenth embodiment of  FIG. 29 . The flow in  FIG. 30  starts when the primary power supply is turned on by the operation unit  1409 ; in step S 162 , there is performed a check for initial startup and for the functions of each unit. Next, in step S 164 , there is an instruction for a short-range communication connection with the mobile telephone  1601 , and the flow moves on to step S 166 . When a short-range communication is established on the basis of the instruction in step S 164 , the headset  1681  enters a state of constant connection with the mobile telephone  1601  unless the primary power supply is subsequently turned off. In step S 166 , there is performed a check for whether short-range communication with the mobile telephone  1601  has been established; the flow moves on to step S 168  when establishment is confirmed. 
     In step S 168 , there is performed a check for whether or not an incoming signal from the mobile telephone  1601  has been transmitted through a short-range communication. Then, when there is an incoming signal, the flow proceeds to step S 170 , in which a drive is performed such that the cartilage conduction vibration unit  1626  has an incoming signal vibration. This incoming signal vibration may have an audible frequency, or may vibrate in a low frequency region with a large enough amplitude that the vibration can be felt with the tragus  32 . Next, in step S 172 , there is performed a check for whether an incoming signal has been stopped by an outgoing call stop operation or the like from the party making the call; when there is no stop, the flow proceeds to step S 174 , in which there is performed a check for whether there has been a receiving operation by the operation unit  1409 . Then, when there is a receiving operation, the flow moves on to step S 176 . On the other hand, when there is no receiving operation in step S 174 , the flow returns to step S 170 , following which a loop of steps S 170  to S 174  is repeated unless either the incoming signal vibration of the cartilage conduction vibration unit  1626  is stopped or a receiving operation is performed. 
     On the other hand, in a case in which no incoming signal is detected in step S 168 , the flow moves on to step S 178 , in which there is performed a check for whether there has been a one-touch outgoing call operation to a registered call destination by the operation unit  1409 . The flow proceeds to step S 180  when an outgoing call operation is detected; the outgoing call operation is transmitted to the mobile telephone  1601  to make an outgoing call, and there is performed a check for whether or not a signal to the effect that a call connection has been established by a response from the other party thereto has been transmitted from the mobile telephone  1601 . When it is confirmed that a call connection has been established in step S 180 , the flow moves on to step S 176 . 
     In step S 176 , the cartilage conduction vibration unit  1626  is turned on in order for audio information to be listened to, and in step S 182  the outgoing-talk unit (microphone)  1423  is turned on in order for speaking to be performed; the flow then moves on to step S 184 . In step S 184 , there is performed a check for whether it has been detected that the movable unit  1591  is bent at or above a predetermined angle. When bending has been detected, the flow then proceeds to step S 186 , in which the waveform inversion signal of one&#39;s own voice is added to the cartilage conduction vibration unit  1626 ; the flow then moves on to step S 188 . On the other hand, when there is no detection in step S 184  that the bending is at or above the predetermined angle, the flow moves on to step S 190 , and then on to step S 188  without the waveform inversion signal of one&#39;s own voice being added to the cartilage conduction vibration unit  1626 . In step S 188 , there is performed a check for whether or not a signal to the effect that the call state has been cut off has been received from the mobile telephone  1601 ; when the call has not been cut off, the flow returns to step S 176 , following which steps S 176  to S 188  are repeated until a call interruption is detected in step S 188 . Support is thereby provided for the generation and elimination of the earplug bone conduction effect that is based on the bending of the movable unit  1591  during a call. 
     On the other hand, when it is detected in step S 188  that a call interruption signal has been received from the mobile telephone  1601 , the flow proceeds to step S 192 , in which listening using the cartilage conduction vibration unit  1626  is turned off and speaking using the outgoing-talk unit (microphone)  1423  is turned off; the flow then moves on to step S 194 . In step S 194 , there is performed a check for whether a no-call state has continued for a predetermined period of time or longer; when this is true, the flow moves on to step S 196 . In step S 196 , there is a shift to a power-saving standby state, such as one in which the clock frequency is lowered to the minimum level required to maintain the standby state of the short-range communication unit  1487 ; processing is also done to permit an interruption for reinstating the short-range communication unit  1487  to an ordinary call state, in response to the receipt of an incoming call signal from the mobile telephone  1601  or an outgoing call operation of the operation unit  1409 . Then, after such processing, the flow moves on to step S 198 . On the other hand, when there is no detection in step S 194  of a no-call state lasting a predetermined period of time or longer, the flow moves directly on to step S 198 . However, the flow also moves directly on to step S 198  when it is not possible in step S 166  to confirm that short-range communication has been established, or when there is no detection in step S 178  of an outgoing call operation, or when it is not possible in step S 180  to confirm that a telephone connection has been established. 
     In step S 198 , there is performed a check for whether the primary power supply has been turned off by the operation unit  1409 , the flow being terminated in a case in which it is detected that the primary power supply has been turned off. On the other hand, in a case in which it is not detected that the primary power supply has been turned off, the flow returns to step S 166 , following which steps S 166  to S 198  are repeated until primary power supply is turned off, to support various changes to the state of the headset  1681 . 
     The flow in  FIG. 30  can be applied not only to the configuration of the system diagram in  FIG. 27 , but also to the system diagram of the fifteenth embodiment in  FIG. 26 . The same can also be applied to the thirteenth embodiment in  FIG. 24  or to the fourteenth embodiment in  FIG. 25  when the “bending detection” in step S 184  is read as a detection of the presence or absence of the state in which the “earplug bone conduction effect” is generated, as in step S 52  of  FIG. 10 . 
     Eighteenth Embodiment 
       FIG. 31  is a flow chart of the controller of a headset in which, instead of having the bending be detected by a mechanical switch in the seventeenth embodiment of  FIG. 30 , the configuration is such that same is achieved using software; the description is provided as an eighteenth embodiment, in order to avoid confusion with  FIG. 30 . Steps that  FIG. 31  has in common with  FIG. 30  have been given like step reference numerals, a description thereof having been omitted unless there is a particular need.  FIG. 31  uses boldface print and bold frames to illustrate points of difference, and thus the following description focuses on these portions. More specifically, the eighteenth embodiment is configured such that, with the assumption that the cartilage conduction vibration unit  1626  is a piezoelectric bimorph element and conforming to the fourth embodiment in  FIG. 9 , a signal appearing on a signal wire for connecting the phase adjustment mixer unit  1636  and the cartilage conduction vibration unit  1626  is monitored, and changes in the signal appearing for the cartilage conduction vibration unit (which is a piezoelectric bimorph element)  1626  are monitored by the strain that is based on the operational impact from the bending of the movable unit  1591  or at the moment of recovery from the bending thereof. The signal change is then processed by software, whereby the bending state is detected. 
     On the basis of the assumption above, there shall now be provided a description of how  FIG. 31  is different from  FIG. 30 . First, step S 200  is depicted by the consolidation of steps S 170  to S 174 , step S 178 , and step S 180  in  FIG. 30 , the content thereof being identical. Then, when a telephone connection is established on the basis of an operation to receive an incoming call or of the response of the other party to an outgoing call, the flow moves on to step S 176 ; when there is no telephone connection, the flow moves on to step S 198 . 
     Steps S 202  to S 210  are steps that relate to detecting bending; once steps S 182  to S 202  are reached, first, a signal appearing on the input terminal of the cartilage conduction vibration unit  1626  (the signal wire connecting the phase adjustment mixer unit  1636  and the cartilage conduction vibration unit  1626 ) is sampled. In step S 204 , drive output of the cartilage conduction unit going from the controller  1639  to the phase adjustment mixer unit  1636  at the same timing is sampled at the same timing. Subsequently, in step S 206 , the difference between these sampling values is calculated, and in step S 208 , there is a detection for whether the calculated difference is at or above a predetermined value. This function corresponds to the function of the pressure sensor  242  in  FIG. 9 , but whereas the pressure state is continuously detected by the pressure sensor  242  of  FIG. 9 , the system in  FIG. 27  uses operational impact from bending or at the moment of recovery from bending to perceive changes to the bending state. 
     When it is detected in step S 208  that the two sampling values have generated a difference at or above the predetermined value, the flow moves on to step S 210 . It is not known at the stage in step S 208  whether the difference in the two sampling values at or above the predetermined value has been generated due to bending or has been generated due to recovery from bending. However, after the cartilage conduction vibration unit  1626  has been turned on in step S 176 , there is a check in step S 210  for whether the number of times a difference has been generated is an odd number, on the basis of the difference generation history. When the number of times is an odd number, the flow moves on to step S 186 , and when the number of times is an even number, the flow moves on step S 190 . Because the movable unit  1591  necessarily alternates between bending and recovering from bending, there can be an alternation between whether or not the phase-inverted signal of one&#39;s own voice is added each time there is an operational impact in the manner described above. However, the difference generation history can be reset using the operation unit  1409  in the event that the difference count is ever inverted by a mistaken operation. 
     Step S 212  is depicted by the consolidation of step S 194  and step S 196  in  FIG. 30 , the content thereof being identical. As described above, similarly with respect to the fourth embodiment and the like, the sensor function of the cartilage conduction vibration unit  1626  itself is utilized in the eighteenth embodiment to detect the bending of the movable unit  1591 , whereby the state in which the earplug bone conduction effect occurs is determined to be in effect. The flow of  FIG. 31  can be applied not only to the configuration of the system diagram in  FIG. 27 , but also to the system diagram of the fifteenth embodiment in  FIG. 26 . Also, in a case such as in the fifth to tenth embodiments, in which the cartilage conduction vibration unit is held by an elastic body, the scheme in  FIG. 31  for detecting the occurrence of the earplug bone conduction effect can also be utilized in a case in which there is no continuous strain on the cartilage conduction vibration unit in the state in which the earplug bone conduction effect occurs. 
     Nineteenth Embodiment 
       FIG. 32  is a structural diagram illustrating the system of the nineteenth embodiment according to an aspect of the present invention. The nineteenth embodiment is also configured as an incoming/outgoing-talk unit for a mobile telephone, and together with the mobile telephone  1401  creates a mobile telephone system. In the nineteenth embodiment, as illustrated in  FIG. 32 , the incoming/outgoing-talk unit is configured as eyeglasses  1781 . Because the nineteenth embodiment assumes a system configuration in common with that of the fifteenth embodiment, common parts have been given like reference numerals; in a case in which there is no particular description, that configuration is shared with that of the fifteenth embodiment. Also, in the nineteenth embodiment as well, the mobile telephone  1401  may in some cases have a special configuration to be used in combination with the eyeglasses  1781  creating an incoming/outgoing-talk unit, and may in other cases be configured as a typical mobile telephone having a short-range communication function. In the latter case, the eyeglasses  1781  take on a configuration as an accessory of the mobile telephone  1401 , similarly with respect to the fifteenth embodiment. 
     In the nineteenth embodiment, as illustrated in  FIG. 32 , a movable unit  1791  is rotatably attached to the temple piece of the eyeglasses  1781 ; in the state depicted, a cartilage conduction vibration unit  1726  is in contact with the tragus  32  of the right ear  28 . The movable unit  1791  can be rotationally withdrawn to a position along the temple of the eyeglasses  1781  as indicated by the single-dotted line  1792  in a case in which same is not to be used. The cartilage conduction vibration unit  1726  can be made to vibrate at low frequency in this withdrawn state as well; it can thereby be known that there is an incoming call when the vibration of the temple of the eyeglasses  1781  is felt on the face. The outgoing-talk unit (microphone)  1723  is arranged at the front portion of the temple of the eyeglasses  1781 . The controller  1739 , which comprises a power supply unit, is arranged at the portion of the temple on the eyeglasses  1781 , and controls the cartilage conduction vibration unit  1726  and the outgoing-talk unit (microphone)  1723 . A Bluetooth™ or other type of short-range communication unit  1787 , which is capable of wireless communication with the mobile telephone  1401  by radio waves  1285 , is further arranged at the portion of the temple on the eyeglasses  1781 , sending audio from the user, which is picked up by the outgoing-talk unit (microphone)  1723 , to the mobile telephone  1401 , and also making it possible to cause the cartilage conduction vibration unit  1726  to vibrate on the basis of the audio information that is received from the mobile telephone  1401 . The rear end part of the temple of the eyeglasses  1781  is provided with an incoming/outgoing-talk operation unit  1709 . Since the temple of the eyeglasses  1781  is a portion that comes against a bone at the rear of the ear  28  (the mastoid part), it is supported in a backed state, and incoming/outgoing-talk operations, such as pressing on the temple from the front side, can be easily performed without causing the eyeglasses  1781  to deform. The arrangement of each of the aforementioned elements is not to be limited to the description above; all or a part of the elements may be integrated in the movable unit  1791  as appropriate. 
     The movable unit  1791 , having an elastic body  1773  interposed partway therealong, is pushed from the outside and caused to bend when listening comprehension of audio information is impaired by environment noise; the cartilage conduction vibration unit  1726  is then pushed on the tragus  32  with greater pressure, whereby the tragus  32  more readily obstructs the hole of the ear. The ear plug conduction effect, which has also been described in the other embodiments, can thereby be generated, and even louder audio information can thereby be transmitted. Information on one&#39;s own voice, which is picked up from the outgoing-talk unit (microphone)  1723 , is also subjected to phase inversion on the basis of the mechanical detection of the bent state of the movable unit  1791 . The information is then transmitted to the cartilage conduction vibration unit  1726 , and one&#39;s own voice is canceled out. These are points in common with the fifteenth embodiment. 
     The block diagrams of  FIGS. 28 and 29  can be applied to the nineteenth embodiment by reading “headset” as “eyeglasses.” The flow charts of  FIGS. 30 and 31  can also be applied to the nineteenth embodiment. 
     Twentieth Embodiment 
       FIG. 33  is a diagram of the system of the twentieth embodiment according to an aspect of the present invention. The twentieth embodiment is also configured as an incoming/outgoing-talk unit for a mobile telephone, and together with the mobile telephone  1401  creates a mobile telephone system. The twentieth embodiment takes the configuration of a system in common with that of the nineteenth embodiment in  FIG. 32 ; therefore, portions that are in common have been given like reference numerals, a description thereof being omitted unless there is a particular need. Also similarly with respect to the nineteenth embodiment, the mobile telephone  1401  in the twentieth embodiment as well may in some cases have a special configuration to be used in combination with a pair of eyeglasses  1881  creating an incoming/outgoing-talk unit, and may in other cases be configured as a typical mobile telephone having a short-range communication function. In the latter case, the eyeglasses  1881  take on a configuration as an accessory of the mobile telephone  1401 , similarly with respect to the nineteenth embodiment. 
     A point of difference in the twentieth embodiment from the nineteenth embodiment lies in that the cartilage conduction vibration unit  1826  is provided within an ear-hook unit  1893 , by which the temple of the eyeglasses  1881  comes up against the base of the ear  28 . As a result thereof, the vibration of the cartilage conduction vibration unit  1826  is transmitted to the outer side  1828  of the cartilage of the base of the ear  28 ; air conduction sound is generated from the inner wall of the external auditory meatus for transmission to the tympanic membrane via the cartilage around the entrance to the external auditory meatus, and a part is also transmitted directly to the inner ear through the cartilage. The outer side  1828  of the cartilage of the base of the ear  28 , against which the temple of the eyeglasses  1881  comes, being close to the inner entrance of the external auditory meatus, is suitable for generating air conduction to the interior of the external auditory meatus from the cartilage around the entrance to the external auditory meatus and for direct conduction to the inner ear through the cartilage. 
     The ear-hook unit  1893  is further provided with an ear pushing detection unit  1888  at the portion coming up against the rear side of the ear lobe. The ear pushing detection unit  188  mechanically detects the state in which the ear lobe is pushed due to the palm of the hand coming against the ear  28  when there is loud external noise, in order to block same; the controller  1739  transmits this ear pushing detection information to the mobile telephone  1401  from the short-range communication unit  1787 . The ear pushing detection unit  1888  can be made of, for example, a switch that is mechanically turned on when pushed by the rear side of the ear lobe. The controller  239  of the mobile telephone  1401  (in the case in which the configuration calls on that of  FIG. 28 ) controls the phase adjustment mixer unit  236  on the basis of the bending detection information received by the short-range communication unit  1446 , and determines whether or not to add, to the audio information from the incoming-talk-processing unit  212 , the signal of the waveform inverter  240  that is based on one&#39;s own voice transmitted from the microphone  1723  to the outgoing-talk-processing unit  222  via the short-range communication unit  1446 . A configuration relating to a countermeasure for when the earplug bone conduction effect is generated, similarly with respect to the nineteenth embodiment, can also be configured by calling on  FIG. 29 . 
     Twenty-First Embodiment 
       FIG. 34  is a side view of the elements of the twenty-first embodiment according to an aspect of the present invention. The twenty-first embodiment is also configured as an incoming/outgoing-talk unit for a mobile telephone, and together with the mobile telephone  1401  (not shown) creates a mobile telephone system, similarly with respect to the twentieth embodiment. The twenty-first embodiment takes the configuration of a system analogous to that of the twentieth embodiment in  FIG. 33 ; therefore, portions that are in common have been given like reference numerals, a description thereof being omitted unless there is a particular need. More specifically, a point of difference is that, whereas the incoming/outgoing-talk unit of the twentieth embodiment is configured as specialized eyeglasses, the incoming/outgoing-talk unit of  FIG. 34  is configured as an eyeglasses attachment  1981  that can be attached to an ear-hook unit  1900  of the temple of ordinary eyeglasses. The configuration is otherwise consistent with that of the twentieth embodiment in  FIG. 33 . Also similarly with respect to the twentieth embodiment, the mobile telephone  1401  (not shown) in the twenty-first embodiment may in some cases have a special configuration to be used in combination with the eyeglasses attachment  1981  creating an incoming/outgoing-talk unit, and may in other cases be configured as a typical mobile telephone having a short-range communication function. In the latter case, the eyeglasses attachment  1981  takes on a configuration as an accessory of the mobile telephone  1401 , similarly with respect to the twentieth embodiment. 
     The eyeglasses attachment  1981  is molded as a one-size-fits-all elastic body cover capable of covering the variously sized and/or shaped ear-hook unit  1900 ; when the ear-hook unit  1900  is inserted from the opening of one end thereof, the cartilage conduction vibration unit  1926  comes into contact with the top side of the ear-hook unit  1900 . This contact may be achieved directly or via the coating of the elastic body of the eyeglasses attachment  1981 . For this purpose, the elastic body is preferably selected to be of a material having an acoustic impedance that approximates that of ear cartilage. The aforementioned direct or indirect contact transmits the vibration of the cartilage conduction vibration unit  1926  to the ear-hook unit  1900 , the vibration thereof then being transmitted to the outer side of the base of the ear  28 ; therefore, similarly with respect to the twentieth embodiment, air conduction sound is generated from the inner wall of the external auditory meatus for transmission to the tympanic membrane via the cartilage around the entrance to the external auditory meatus, and a part is also transmitted directly to the inner ear through the cartilage. 
     Each of the outgoing-talk unit (microphone)  1723 , the controller  1739 , the short-range communication unit  1787 , the incoming/outgoing-talk operation unit  1709 , and the ear pushing detection unit  1888  provided to the eyeglasses  1881  in the twentieth embodiment is arranged within the eyeglasses attachment  1981  in the twenty-first embodiment in  FIG. 34 ; however, the functions thereof are shared and therefore a description has been omitted. Although not depicted, in a case in which, for example, the ear-hook unit  1900  on the right is covered with the eyeglasses attachment  1981 , a dummy cover molded from an elastic body having the same outer shape, material, and weight is provided as an ear-hook unit on the left. Covering the eyeglasses attachment  1981  makes it possible to keep the left-right balance when the eyeglasses are worn. Since the eyeglasses attachment  1981  and the dummy cover are molded using the same elastic body, they can accordingly be configured such that each can be worn as desired as either the left or right ear-hook unit by being slightly deformed. For example, as the inverse of the description above, the left ear-hook unit can be covered with the eyeglasses attachment  1981  and the right ear-hook unit can be covered with the dummy cover. There is accordingly no need to market an assortment of eyeglasses attachments  1981  for either right ear use or left ear use. 
     Twenty-Second Embodiment 
       FIG. 35  is a top view of the twenty-second embodiment according to an aspect of the present invention. The twenty-second embodiment is also configured as an incoming/outgoing-talk unit for a mobile telephone, and together with the mobile telephone  1401  (not shown) creates a mobile telephone system, similarly with respect to the twenty-first embodiment. The twenty-second embodiment takes the configuration of a system analogous to that of the twenty-first embodiment in  FIG. 34 ; therefore, portions that are in common have been given like reference numerals, a description thereof being omitted unless there is a particular need. The incoming/outgoing-talk unit of the twenty-second embodiment, similarly with respect to the twenty-first embodiment, is also configured as an eyeglasses attachment  2081  that is molded as a one-size-fits-all elastic body cover capable of covering the variously sized and/or shaped ear-hook unit  1900  in ordinary eyeglasses. 
     A point of difference in the twenty-second embodiment in  FIG. 35  from the twenty-first embodiment in  FIG. 34  lies in that each of the constituent elements of the incoming/outgoing-talk unit, which in the twenty-first embodiment are arranged concentratedly in the eyeglasses attachment  1981 , one side of which is covered with the ear-hook unit  1900 , are distributed in the left and right ear-hook unit  1900 . More specifically, the eyeglasses attachment  2081  of the twenty-second embodiment is made of a right-side elastic body cover  2082 , a left-side elastic body cover  2084 , and a dual-purpose glass-cord cable  2039  for connecting same to be able to communicate via a wire; each of the constituent elements of the incoming/outgoing-talk unit being arranged in a distributed fashion therein. For convenience of description, the elastic body cover  2082  is intended for use on the right ear and the elastic body cover  2084  is intended for use on the left ear, but each of the ear-hook units  1900  can be covered with this pair of elastic body covers in a left-right inversion. 
     In the aforementioned basic configuration, the cartilage conduction vibration unit  1926 , the incoming/outgoing-talk operation unit  1709 , and the ear pushing detection unit  1888  are arranged on the right-side elastic body cover  2082 . Similarly with respect to the twenty-first embodiment, the vibration of the cartilage conduction vibration unit  1926  is thereby transmitted to the cartilage around the opening of the external auditory meatus via the ear-hook unit  1900 . Air conduction sound is generated from the wall inside the external auditory meatus and transmitted to the tympanic membrane, and a part is transmitted directly to the inner ear through the cartilage. 
     On the other hand, the outgoing-talk unit (microphone)  1723 , the controller  1739 , and the short-range communication unit  1787  are arranged on the left-side elastic body cover  2084 . The dual-use glass-cord cable  2039  has a glass cord design so that the eyeglasses can be hung on the neck when removed, and functions through wiring that connects each of the constituent elements of the incoming/outgoing-talk unit, which are arranged in a distributed fashion in the right-side elastic body cover  2082  and the left-side elastic body cover  2084 . Connecting the right-side elastic body cover  2082  and the left-side elastic body cover  2084  using the dual-use glass-cord cable  2039  prevents one side from being misplaced when removed from the eyeglasses. 
     Twenty-Third Embodiment 
       FIG. 36  is a block diagram of the twenty-third embodiment according to an aspect of the present invention. The twenty-third embodiment, similarly with respect to either the nineteenth embodiment or the twentieth embodiment, includes eyeglasses  2181  configured as an incoming/outgoing-talk unit for a mobile telephone, and together with the mobile telephone  1401  (not shown) creates a mobile telephone system. Similarly with respect to the twenty-second embodiment, each element constituting the incoming/outgoing-talk unit in the twenty-third embodiment is arranged in a distributed fashion to a right temple unit  2182  and a left temple unit  2184 . The individual constituent elements and the functions thereof can be understood in accordance with the block diagram of the seventeenth embodiment in  FIG. 29  and that of the top view of the twenty-second embodiment in  FIG. 35 ; therefore, portions that are in common have been given like reference numerals, a description thereof being omitted unless there is a particular need. In the twenty-third embodiment as well, the vibration of the cartilage conduction vibration unit  1826  arranged at the right temple unit  2182  is transmitted to the outer side of the cartilage of the base of the ear  28 ; this causes the cartilage around the entrance to the external auditory meatus to vibrate, whereby air conduction sound generated from the wall inside the external auditory meatus is transmitted to the tympanic membrane, and a part of the cartilage vibration is directly transmitted to the inner ear through the cartilage. 
     The twenty-third embodiment in  FIG. 36  further has a configuration for visualizing a three-dimensional (“3D”) image received from the mobile telephone  1401  in a lens unit  2186 . The lens unit  2186  of the eyeglasses  2181  is provided with a right lens  2110  and a left lens  2114  originally intended for eyeglasses, and functions as ordinary eyeglasses. Furthermore, when the short-range communication unit  1787  receives 3D image information from the mobile telephone  1401 , the controller  1639  instructs a 3D display drive unit  2115  to display same. The 3D display drive unit  2115 , on the basis thereof, causes a right eye image and left eye image to be displayed on a right display unit  2118  and a left display unit  2122 , respectively. These images are imaged on the retinas of the right eye and the left eye by a right eye light-guiding optical system  2129  and a left eye light-guiding optical system  2141 , which comprise an imaging lens, a half mirror, and other components; and it will be possible to appreciate the 3D image in an aesthetic sense. This 3D image is viewed in a form that is synthesized with or superimposed on a raw image that enters the retinas from the right lens  2110  and the left lens  2114 . 
     Twenty-Fourth Embodiment 
       FIG. 37  is a diagram of the system of the twenty-fourth embodiment according to an aspect of the present invention. The twenty-fourth embodiment is also configured as an incoming/outgoing-talk unit for a mobile telephone, and together with the mobile telephone  1401  creates a mobile telephone system. The incoming/outgoing-talk unit of the twenty-fourth embodiment, although being configured as an ear-hook unit  2281  used for hearing aids or the like, otherwise takes the configuration of a system in common with that of the twentieth embodiment in  FIG. 33 ; therefore, portions that are in common have been given like reference numerals, a description thereof being omitted unless there is a particular need. Also similarly with respect to the twentieth embodiment, the mobile telephone  1401  in the twenty-fourth embodiment may in some cases have a special configuration to be used in combination with the ear-hook unit  2281  creating an incoming/outgoing-talk unit, and may in other cases be configured as a typical mobile telephone having a short-range communication function. In the latter case, the ear-hook unit  2281  takes on a configuration as an accessory of the mobile telephone  1401 , similarly with respect to the twentieth embodiment. 
     In the twenty-fourth embodiment, the cartilage conduction vibration unit  2226  is arranged at a position coming up against the rear part of the outer side  1828  of the cartilage of the base of the ear  28 . As a result thereof, similarly with respect to the twentieth embodiment, the vibration of the cartilage conduction vibration unit  2226  is transmitted to the outer side  1828  of the cartilage of the base of the ear  28 ; air conduction sound is generated from the inner wall of the external auditory meatus for transmission to the tympanic membrane via the cartilage around the entrance to the external auditory meatus, and a part is also transmitted directly to the inner ear through the cartilage. The outer side  1828  of the cartilage of the base of the ear  28 , being close to the inner entrance of the external auditory meatus thereof, is suitable for generating air conduction to the interior of the external auditory meatus from the cartilage around the entrance to the external auditory meatus and for direct conduction to the inner ear through the cartilage. However, in the case in which the incoming/outgoing-talk unit is configured as an ear-hook unit  2281 , as in the twenty-fourth embodiment, there is a great degree of freedom in the arrangement of the cartilage conduction vibration unit  2226  for making contact with the outer side  1828  of the cartilage of the base of the ear  28 ; therefore, the cartilage conduction vibration unit  2226  can be arranged at an optimum position, taking into consideration the mounting layout and vibration conduction effect for the structure of the incoming/outgoing-talk unit. Accordingly, similarly with respect to the twentieth embodiment, in the twenty-fourth embodiment there may also be employed an arrangement by which the cartilage conduction vibration unit  2226  comes up against the upper part of the outer side  1828  of the cartilage of the base of the ear  28 . 
     The ear-hook unit  2281 , similarly with respect to the case of the eyeglasses  1881  in the twentieth embodiment, is provided with an outgoing-talk unit (microphone)  1723 , a controller  1739 , a short-range communication unit  1787 , an incoming/outgoing-talk operation unit  1709 , and an ear pushing detection unit  1888 , the associated functions being consistent therewith and an attendant description accordingly being omitted. In the case of the ear-hook unit  2281  of the twenty-fourth embodiment, the outgoing-talk unit (microphone)  1723  is arranged frontwardly with respect to the ear. 
     Twenty-Fifth Embodiment 
       FIG. 38  is block diagram of the twenty-fifth embodiment according to an aspect of the present invention. The twenty-fifth embodiment is consistent with the twentieth to twenty-third embodiments in that the cartilage conduction vibration units  2324  and  2326  are arranged at the ear-fitting parts of the temples of an eyeglasses-type device and in that the vibration is transmitted to the outer side of the cartilage of the base of the ear  28 ; however, this embodiment is configured not as an incoming/outgoing-talk unit of a mobile telephone but rather as 3D television viewing eyeglasses  2381 , and together with a 3D television  2301  creates a 3D television viewing system. The twenty-fifth embodiment makes it possible to experience stereo audio information; the vibration of a right-ear cartilage-conduction vibration unit  2324  arranged at the right temple unit  2382  is transmitted to the outer side of the cartilage of the base of the right ear via a contact unit  2363 , and causes the cartilage around the entrance to the external auditory meatus to vibrate, air conduction sound that is thereby generated from the wall inside the external auditory meatus being transmitted to the right tympanic drum, and a part of the cartilage conduction being transmitted directly to the inner ear through the cartilage. Similarly, the vibration of a left-ear cartilage-conduction vibration unit  2326  arranged at the left temple unit  2384  is transmitted to the outer side of the cartilage of the base of the left ear via a contact unit  2364 , and causes the cartilage around the entrance to the external auditory meatus to vibrate, whereby air conduction sound that is generated from the wall inside the external auditory meatus is transmitted to the left tympanic drum, and a part of the cartilage conduction is transmitted directly to the inner ear through the cartilage. 
     The viewing eyeglasses  2381  are configured to be wearable over ordinary eyeglasses by any person wearing the same; in this case, the vibrations of the right-ear cartilage-conduction vibration unit  2324  and the left-ear cartilage-conduction vibration unit  2326  are respectively transmitted to the cartilage of the base of the left and right ears, which are in direct contact therewith via the contact units  2363  and  2364 , and are also respectively transmitted to the ear-hook units of the left and right temples of the ordinary eyeglasses and indirectly transmitted to the cartilage of the base of the ear via the ear-hook units. The contact units  2363  and  2364  are configured in a shape such that cartilage conduction appropriate for the cartilage of the base of the ear is generated, both in a case in which a person without eyeglasses wears the viewing eyeglasses  2381  and in a case in which they are worn over ordinary eyeglasses. A description thereof will be provided further below. 
     The 3D television  2301  generates an audio signal from a stereo audio signal unit  2331  on the basis of the control of the controller  2339 ; an infrared communication unit  2346  transmits this audio signal to an infrared communication unit  2387  of the viewing eyeglasses  2381  using infrared rays  2385 . The controller  2339  of the viewing eyeglasses  2381  outputs a left and a right audio signal from a right audio drive unit  2335  and a left audio drive unit  2336  on the basis of the received audio signal, and causes the right-ear cartilage-conduction vibration unit  2324  and the left-ear cartilage-conduction vibration unit  2326  to vibrate. The aforementioned infrared communication unit  2387 , the controller  2339 , the right audio drive unit  2335 , the left audio drive unit  2336 , as well as a shutter drive unit  2357 , a right shutter  2358  and a left shutter  2359  (to be described later), together with a power supply unit  2348 , are arranged on an eyeglasses primary unit  2386 . 
     On the other hand, the 3D television  2301  sends a video signal of a video signal unit  2333  to a display driver  2341  on the basis of the control of the controller  2339 , and displays a 3D image on a 3D screen  2305  comprising a liquid crystal display unit or the like. The controller  2339  further synchronizes with the 3D image display to generate a synchronization signal from a 3D shutter synchronization signal unit  2350 , and the infrared communication unit  2346  transmits this synchronization signal to the infrared communication unit  2387  of the viewing eyeglasses  2381  using the infrared rays  2385 . The controller  2339  of the viewing eyeglasses  2381  controls the shutter drive unit  2357  on the basis of the received synchronization signal, and opens the right shutter  2358  and the left shutter  2359  in alternation. A right eye image  2360  and a left eye image  2362 , which are displayed in alternation on the 3D screen  2305 , are thereby made to be incident on the right eye and the left eye in synchronization. In the twenty-fifth embodiment, the stereo audio signal for driving the cartilage conduction vibration unit and the 3D shutter synchronization signal are thus transmitted by the infrared communication between the infrared communication units  2346  and  2387 . These two signals are sent in parallel by either time division or by synthesis. The communication therebetween is not to be limited to communication by infrared rays, but rather may be achieved using short-range wireless communication, as in other embodiments. 
       FIG. 39  is a cross-sectional view of the elements of the aforementioned twenty-fifth embodiment; the cross-section of the right temple unit  2382  is illustrated in a state in which the viewing eyeglasses  2381  have been worn since the ordinary eyeglasses were put on.  FIG. 39A  is a cross-section of the right temple unit  2382  relating to the twenty-fifth embodiment, and  FIG. 39B  illustrates a cross-section of a modification example thereof. First, a description of  FIG. 39A  shall be provided. A contact unit  2363  is provided to the portion of the bottom of the right temple unit  2382  that is worn on the ear  28 . This contact unit  2363  comprises an elastic body having an acoustic impedance approximating that of ear cartilage, and the right-ear cartilage-conduction vibration unit  2324  is held in the right temple unit  2382  configured so as to be enveloped therein. The cross-section of the contact unit  2363 , as is clear from  FIG. 39A , is provided with a groove into which the ear-hook unit  2300  of the ordinary eyeglasses is to be fitted. The right temple unit  2382  of the viewing eyeglasses  2381  achieves reliable contact with the ear-hook unit  2300  of the temple of the ordinary eyeglasses, and the elasticity of the contact unit  2363  prevents the contacted portions of the right temple unit  2382  and the ear-hook unit  2300  from buzzing due to vibration. In the state of  FIG. 39A , the vibration of the right-ear cartilage-conduction vibration unit  2324  is transmitted to the outer side  1828  of the cartilage of the base of the right ear  28 , in direct contact therewith via the contact unit  2363 , and is also transmitted to the ear-hook unit  2300  of the right temple of the ordinary eyeglasses, and indirectly transmitted to the outer side  1828  of the cartilage of the base of the ear  28  via this ear-hook unit  2300 . 
     On the other hand, in a case in which a person without eyeglasses wears the viewing eyeglasses  2381  directly, the entire contact unit  2363  is in direct contact with the outer side  1828  of the cartilage of the base of the right ear  28 , and transmits the vibration of the right-ear cartilage-conduction vibration unit  2324  thereto. The outer side of the contact unit  2363  is beveled, and therefore the right temple unit  2382  will fit to the ear  28  without discomfort even in this case. 
     Next, in a modification example in  FIG. 39B , as is clear from the cross-sectional view thereof, a contact unit  2363  is provided to the portion of the bottom of the right temple unit  2382  that is worn on the ear  28 , similarly with respect to  FIG. 39A . Also similarly with respect to  FIG. 39A , the contact unit  2363  comprises an elastic body having an acoustic impedance approximating that of ear cartilage, and the right-ear cartilage-conduction vibration unit  2324  is held at the right temple unit  2382  configured so as to be enveloped therein. As is clear from  FIG. 39B , the cross-sectional shape of the contact unit  2363  is different in the modification example, a concave slope being provided instead of the groove; the right temple unit  2382  of the viewing eyeglasses  2381  thereby achieves reliable contact with the outer side of the ear-fitting part  2300  of the temple of the ordinary eyeglasses so as to be hooked on the ear  28 , and the elasticity of the contact unit  2363  prevents the contact portions of the right temple unit  2382  and the ear-hook unit  2300  from buzzing due to vibration. In the state of  FIG. 39B , the vibration of the right-ear cartilage-conduction vibration unit  2324  is transmitted to the outer side  1828  of the cartilage of the base of the right ear  28 , in direct contact therewith via the contact unit  2363 , and is also transmitted to the ear-hook unit  2300  of the right temple of the ordinary eyeglasses, and indirectly transmitted to the outer side  1828  of the cartilage of the base of the ear  28  via this ear-hook unit  2300 . 
     On the other hand, in a case in which a person without eyeglasses wears the viewing eyeglasses  2381 , the entire contact unit  2363  is in direct contact with the outer side  1828  of the cartilage of the base of the right ear  28 , and transmits the vibration of the right ear conduction vibration unit  2324  thereto. The outer side of the contact unit  2363  is also beveled in the case of the modification example in  FIG. 39B ; the right temple unit  2382  is fitted to the ear  28  without discomfort even in a case in which the viewing eyeglasses  2381  are worn directly. As is clear from  FIG. 39B , it is the contact with the ear cartilage of the bottom or the outer side of the temple of the eyeglasses that is essential in cartilage conduction, and not with the facial cartilage at the inner side of the temple of the eyeglasses; the shape of the contact unit is determined to meet this purpose. 
     As described above, in the twentieth to twenty-fifth embodiments, the vibration of the cartilage conduction vibration unit  2324  is transmitted to the outer side of the cartilage of the base of the ear. This causes the cartilage around the entrance to the external auditory meatus to vibrate, whereby air conduction sound that is generated from the wall inside the external auditory meatus is transmitted to the tympanic membrane, and a part of the cartilage conduction is directly transmitted to the right inner ear through the cartilage. Favorable conduction by contact with the outer side of the ear cartilage can accordingly be achieved merely by wearing the eyeglasses in an ordinary state. By contrast, in a case using conventional bone conduction, the bone at the front or the rear of the ear must be tightly tucked in by the portion of the inner side of the temple of the eyeglasses, which results in pain and renders long-term usage unbearable. The present invention does not have such a problem, it being possible to listen comfortably to audio information while experiencing a sensation similar to that of ordinary eyeglasses. 
     The various features of each of the embodiments described above are not to be restricted to individual embodiments, but rather can be substituted or combined with other appropriate embodiments. For example, in the description of the twenty-first embodiment in  FIG. 34 , the ear-hook unit of the other temple is covered with a dummy cover, but the configuration of  FIG. 34  can be prepared as a pair; when the ear-hook units of the left and right temples are made to be each covered, it becomes possible to listen to stereo audio signals as in the twenty-fifth embodiment of  FIG. 38 . The two ear-hook units can also be connected by wireless connection at this time, but a connection by the dual-use glass-cord cable as in the twenty-second embodiment of  FIG. 35  is also possible. Regarding the feature of the glass cord, a link between the configuration of  FIG. 34  and the dummy cover in the twenty-first embodiment may be made with a glass cord, thus preventing misplacement. Regarding the aforementioned feature of achieving a stereo effect, when the twenty-third embodiment of  FIG. 36  is also configured such that the constituent elements are not divided into left and right similarly with respect to the description above, but rather two sets of the required constituent elements are prepared and each is positioned at the left and right temple units, it becomes possible not only to make an image into 3D but also to listen to stereo audio signals, as in the twenty-fifth embodiment of  FIG. 38 . Referring to the twenty-fifth embodiment, a part the left-right configuration at this time can be shared as appropriate (for example, at least the controller and the power supply). 
     In the aforementioned embodiments, the effects of the present invention have been described by way of example using a mobile telephone and an incoming/outgoing-talk unit thereof or 3D video viewing eyeglasses. However, the advantages of the present invention are not to be limited thereto; the invention can be implemented in other applications. For example, the various features of the present invention described above would also be effective when implemented in a hearing aid. 
     The various features of each of the embodiments described above are not to be limited to the individual embodiments; rather, wherever it is possible to benefit from the feature of an embodiment, same may be variously implemented in an embodiment in which the feature has been modified. For example,  FIG. 40  is a perspective view illustrating a modification example of the tenth embodiment in  FIG. 19 . In this modification example as well, similarly with respect to  FIG. 19 , the cartilage conduction vibration source  925 , which comprises a piezoelectric bimorph element or the like, serves as the cartilage conduction vibration source, while also taking the role of a drive source of the incoming-talk unit for generating sound waves that are transmitted to the tympanic membrane by air conduction. However, the cartilage conduction vibration source  925  stretches to the side of the mobile telephone  901  in the modification example of  FIG. 40 , the right end  224  and left end  226  thereof being made to vibrate. Sound can accordingly be heard by cartilage conduction due to either one thereof being caused to contact the tragus, similarly with respect to the nineteenth embodiment. The cartilage conduction vibration source  925  vibrates as a whole, rather than vibrating at only the right end  224  and left end  226  thereof. Audio information can accordingly be transmitted regardless of where on the top inner edge of the mobile telephone  901  contact with the ear cartilage is made, similarly with respect to  FIG. 19 . Also, a point of similarity with  FIG. 19  lies in that the cartilage conduction output unit  963 , which is made of a material having an acoustic impedance approximating that of ear cartilage, is arranged frontwardly with respect to the cartilage conduction vibration source  925 . 
     The following is a possible modification example for the twenty-third embodiment of  FIG. 36 . Namely, the outgoing-talk unit (microphone)  1723  in the twenty-third embodiment is an ordinary air conduction microphone, but when the outgoing-talk unit (microphone)  1723  is instead a bone conduction microphone (a microphone or pickup of the bone conduction contact type), it becomes possible to selectively pick up the audio of the speaking party without picking up any undesired sound when in the presence of noise. It further becomes possible to speak in an undertone that will not disturb the surroundings. It is natural that the temples of eyeglasses are generally in contact with the bone at the front of the ear (the zygomatic arch, or a part of the temporal bone on the zygomatic arch) or the bone at the rear of the ear (the mastoid process of the temporal bone). Accordingly, calling on  FIG. 36 , arranging the outgoing-talk unit (microphone)  1723 , which is constituted of a microphone of the bone conduction contact type, at the contact unit with the aforementioned bones in the left temple unit  2184  of the eyeglasses makes it possible to pick up the audio of the speaking party by bone conduction. Dividing the cartilage conduction vibration unit  1826  and the outgoing-talk unit (microphone)  1723 , constituted of a microphone of the bone conduction contact type, to the left and right temple units  2182  and  2184 , as in  FIG. 36 , makes it possible to prevent the microphone of the bone conduction contact type from picking up the vibration from the cartilage conduction vibration unit  1826 . 
     In the twenty-third embodiment of  FIG. 36  or a modification example as described above, it is also possible to omit the configuration related to 3D display from the lens unit  2186  and to make an ordinary eyeglasses configuration with only the right lens  2110  and left lens  2114 . 
     On the other hand, the following is another possible modification example, for the twenty-fifth embodiment of  FIG. 38 . Specifically, since the twenty-fifth embodiment is configured as the viewing eyeglasses  2381 , the sound source of the stereo audio information resides in the 3D television  2301 , and the right-ear cartilage-conduction vibration unit  2324  and the left-ear cartilage-conduction vibration unit  2326  are made to vibrate on the basis of the audio signal received by the infrared communication unit  2387 . However, when the configuration is instead such that a stereo audio signal unit serving as the sound signal source unit of the stereo audio information, and an audio memory for providing data thereto, are housed in the eyeglasses primary unit  2386  or one of the right temple unit  2382  and the left temple unit  2384  of  FIG. 38 , or are divided and then housed in both, then the present invention can be configured as an independent portable music player. Calling on  FIG. 38  to facilitate understanding of the configuration of such a modification example, the aforementioned stereo audio signal unit and audio memory for providing data thereto are to be included in the controller  2339 . In the case of this modification example, there is no need for a link with the 3D television  2301 ; therefore, instead of the right shutter  2358 , the left shutter  2359 , and the shutter drive unit  2357  in  FIG. 38 , a right lens and left lens of ordinary eyeglasses such as in the twenty-third embodiment of  FIG. 36  are arranged on the eyeglasses primary unit  2386 . 
     In the case of the above-described modification example in which the right lens and left lens are arranged at the eyeglasses primary unit  2386  to make ordinary eyeglasses, the controller, the audio drive unit, the infrared communication units, the power supply unit, and the other respective constituent elements arranged at the eyeglasses primary unit  2386  in  FIG. 38  may be divided and arranged at the right temple unit and the left temple unit as appropriate, as in the twenty-third embodiment of  FIG. 36 , thereby preventing any increase in the size of the eyeglasses primary unit  2386 . The infrared communication unit  2387  in the modification example is responsible for functions such as inputting sound source data from a PC or other external sound source data holding device. Using a handheld remote control or the like, the infrared communication unit  2387  can be made to function as a wireless communication unit for adjusting the volume from the right-ear cartilage-conduction vibration unit  2324  and the left-ear cartilage-conduction vibration unit  2326 , or for adjusting the balance of the left and right vibration output. It is furthermore possible to receive the audio information of a mobile telephone when the portable music player is linked to the mobile telephone. In such a case, when the portable music player is provided with an air conduction microphone or a bone conduction microphone, the portable music player can be made to function as a device of the mobile telephone used for incoming talk or outgoing talk made with an external party. 
     The above-described innovative arrangement of the constituent elements to the eyeglasses primary unit  2386  and to the right temple unit  2382  and left temple unit  2384  is not to be limited to the aforementioned modification example. For example, the controller  2339 , the infrared communication unit  2387 , the power supply unit  2348 , the right audio drive unit  2335 , and the left audio drive unit  2336  may also be divided and arranged in the right temple unit  2382  and the left temple unit  2384  as appropriate in the case of the actual viewing eyeglasses  2381  in the twenty-fifth embodiment of  FIG. 38 . 
     Twenty-Sixth Embodiment 
       FIG. 41  is a perspective view of the twenty-sixth embodiment according to an aspect of the present invention, and is configured as a mobile telephone. A mobile telephone  2401  of the twenty-sixth embodiment, similarly with respect to that of the modification example of the tenth embodiment depicted in  FIG. 40 , is an integrated type with no moving parts, and is configured as a “smartphone”, which has the large-screen display unit  205  provided with GUI functions. There is much in common with the structure thereof, and so corresponding portions have been given like reference numerals as in  FIG. 40 , and a description has been omitted. Similarly with respect to the tenth embodiment and the modification example thereof, “upper part” in the twenty-sixth embodiment also does not signify a separated upper part but rather signifies the portion at the top of the integrated structure. 
     A point of difference in the twenty-sixth embodiment from the modification example of the tenth embodiment illustrated in  FIG. 40  lies in that the vibration of the cartilage conduction vibration source  925  has a dual purpose as a vibration source for creating a feedback sensation for a touch operation in the touch panel function of the large-screen display unit  205 . More specifically, a vibration isolation material  2465  made of a vinyl system, a urethane system, or another system is provided between the cartilage conduction vibration source  925  and the configuration located therebelow (the large-screen display unit  205 ), the configuration being such that an audio signal from the cartilage conduction is prevented from being likely to be transmitted to the large-screen display unit  205  or the like, due to the difference in acoustic impedance or the like. On the other hand, when the large-screen display unit  205  is touched and any type of input from the touch panel function thereof is thereby accepted, the cartilage conduction vibration source  925  is made to vibrate at a low frequency at or below the audible range, in order to provide feedback to the finger that has touched the same. The vibration frequency is selected to be a frequency that substantially matches the resonance frequency of the vibration isolation material  2465 ; therefore, the vibration isolation material  2465  resonates due to the vibration of the cartilage conduction vibration source  925 , which vibration is then transmitted to the large-screen display unit  205 . The vibration isolation material  2465 , which prevents vibration in the audio region, thus functions as a vibration transmission material for low-frequency vibration for feedback. Low-frequency vibration can thereby be transmitted to the finger that touched the large-screen display unit  205 , and it can be known that the touch input has been accepted. To prevent conflation of the impact of the touch operation itself with the feedback vibration in response thereto, the cartilage conduction vibration source  925  is provided with a predetermined delay from the moment of touch, and is made to provide the feedback vibration after the touch impact has settled. 
     The twenty-sixth embodiment is provided with an operation button  2461 , which is used for operations such as turning the touch panel function of the large-screen display unit  205  on and off. Also, for the sake of simplifying the drawings, the configuration of the twenty-sixth embodiment omits the cartilage conduction output unit  963 , which has been provided to the modification example of the tenth embodiment illustrated in  FIG. 40 ; however, same can be provided as desired. 
       FIG. 42  is a block diagram of the twenty-sixth embodiment; identical portions have been given like reference numerals to those in  FIG. 41 , and a description thereof has been omitted. The configuration of the block diagram in  FIG. 42  has many points in common with the block diagram of the fourth embodiment in  FIG. 8 , and can call on the configuration of the conceptual block diagram of the elements in  FIG. 9 ; therefore, parts of the configuration in common with  FIG. 8  have been given like reference numerals and a description thereof has been omitted. 
     The large-screen display unit  205  of  FIG. 42  is illustrated as having a touch panel  2468 , and a touch panel driver  2470 , which is controlled by a controller  2439  and drives the touch panel  2465 ; however, this is not specific to the twenty-sixth embodiment, but rather is shared with other embodiments in which the large-screen display unit  205  has a touch panel function, and has merely been omitted from the diagrams of the other embodiments in order to avoid complication.  FIG. 42  illustrates vibration isolation materials  2465  respectively for the portions of the cartilage conduction vibration source  925  and the touch panel  2468 , but this has been described in such a manner merely because of the space limitations of the block diagram. The vibration isolation material  2465  is the same, and the description does not mean that it is separated and provided to respective positions on the cartilage conduction vibration source  925  and the touch panel  2468 . In other words, the intended illustration in  FIG. 42  is that the vibration isolation material  2465  resonates due to the low-frequency vibration of the cartilage conduction vibration source  925 , which vibration is transmitted to the touch panel  2468 . 
     As illustrated in  FIG. 42 , the twenty-sixth embodiment is provided with a low-frequency source  2466  for generating a drive signal of a frequency that substantially matches the resonance frequency of the vibration isolation material  2465 ; the controller  2439  instructs that a low frequency be outputted from the low-frequency source  2466  after a predetermined delay has elapsed from when the touch panel driver  2470  senses the touch of a finger and accepts the input. The phase adjustment mixer unit  2436  drives the cartilage conduction vibration source  925  on the basis of a signal from the telephone function unit  45  in a call state; however, the signal from the telephone function unit  45  being blocked during a non-call operation state in which the touch panel  2468  is operated, the cartilage conduction vibration source  925  is instead driven on the basis of a signal from the low frequency source  2466 . However, in a call state, the phase unit adjustment mixer unit  2436  blocks the signal from the low frequency source  2466 . 
     The function of the controller  2439  of  FIG. 42  in the twenty-sixth embodiment calls on the flow chart of the fourth embodiment in  FIG. 10 . Also, the dual purpose of the cartilage conduction vibration source  925  as a touch operation feedback sensation vibration source, which is a feature of the twenty-sixth embodiment, can be understood as a detailed function of step S 42  in  FIG. 10 . 
     As described above,  FIG. 43  serves to provide a detailed illustration of step S 42  in  FIG. 10 ; when the flow starts, step S 222  first has a check for whether a non-call operation has been performed. This step is similar to step S 6  in the first embodiment of  FIG. 4 , and is a check for the presence or absence of an e-mail operation and/or Internet operation, as well as other operations in which radio operations are not used, such as various settings and also downloaded games, and other non-call operations. Then, when there has been such an operation, the flow proceeds to step S 224 , in which there is performed a check for whether or not the touch panel  2468  is in a non-sensing state. When a non-sensing state is not in effect, the cartilage conduction vibration unit, including the cartilage conduction vibration source  925 , is turned on in step S 226 . On the other hand, in a case in which it is detected in step S 224  that the touch panel  2468  is in a non-sensing state, a non-call operation signifies one by the operation button  2461 , and the flow therefore moves on to step S 228 , in which there is button setting processing corresponding to the operation. Subsequently, in step S 230 , there is performed a check for whether the touch panel  2468  has been set to be activated by the button operation; when this is true, the flow moves on to step S 226 . However, in either a case in which there is no detection in step S 222  of a non-call operation, or a case in which there is no detection in step S 230  of a setting to activate the touch panel  2468 , the flow is immediately terminated. 
     When the cartilage conduction vibration unit is turned on in step S 226 , the flow proceeds to step S 232 , in which the phase adjustment mixer unit  2436  is controlled to sever the output from the telephone function unit  45 ; in step S 234 , the output of the low frequency source  2466  is connected to the cartilage conduction vibration source  925 , and the flow arrives at step S 236 . In step S 236  there is a check for the presence or absence of a touch panel operation; when there is a touch panel operation, the flow proceeds to step S 238 , and there is response processing in accordance with the operation. The flow then proceeds to step S 240 , in which a predetermined period of delay (for example, 0.1 seconds) is allowed to pass, and the flow moves on to step S 242 . In step S 242 , a low frequency is outputted from the low frequency source  2466  for a predetermined period of time (for example, 0.5 seconds), and the operation sensation is fed back to the finger with which the operation is performed; the flow then proceeds to step S 244 . 
     In step S 244 , there is performed a check for whether the touch panel  2468  has been in an operation-less state for a predetermined period of time (for example, 3 seconds) or longer after the latest touch panel operation; when this is not true, the flow returns to step S 236 . Afterwards, steps S 236  to S 244  are repeated as long as the touch panel  2468  is continuously operated for a predetermined period of time; the touch panel input and the operation sensation feedback by the cartilage conduction vibration source  925  are continued. 
     On the other hand, when there is a detection in step S 244  that the touch panel  2468  has remained in an operation-less state for the predetermined period of time or longer, the flow moves on to step S 246 , in which the cartilage conduction vibration unit is turned off; in step S 248 , the phase adjustment mixer unit  2436  is further controlled and the output from the telephone function unit  45  is connected to the cartilage conduction vibration source  925 ; and in step S 250 , the output of the low frequency source  2466  is severed, the flow then terminating for the time being. The flow thereafter being executed in accordance with  FIG. 10 , when no call is detected in step S 44  of  FIG. 10 , the flow immediately moves to step S 34 ; when the primary power supply is not off, the flow then returns to step S 42 ; therefore, the flow in  FIG. 43  is resumed. There is accordingly a swift return to step S 236  whenever the operation of the touch panel lasts for the predetermined period of time and the flow in  FIG. 43  from step S 244  terminates, and the touch panel input and the operation sensation feedback by the cartilage conduction vibration source  925  can be continued. 
     The implementation of the present invention is not to be limited to the aforementioned embodiments; various modifications are possible. For example, the vibration isolation material  2465  in the twenty-sixth embodiment is not limited to a material having a band-pass filter function for transmitting the vibration of the resonance frequency, and may be a material having a low-pass filter function for blocking the vibration from the telephone function unit  45  at or above a predetermined frequency, which is in the audio signal region, and for transmitting the vibration of the low frequency source  2466  for the touch operation feedback, which is in a lower frequency region. 
     Twenty-Seventh Embodiment 
     The following calls on  FIGS. 41 to 43  in the twenty-sixth embodiment to provide a description of the twenty-seventh embodiment of the present invention. In this case, the “touch panel  2468 ” in  FIG. 42  is to be read as a “motion sensor  2468 ,” and the “touch panel driver  2470 ” is to be read as a “motion sensor driver  2470 .” The twenty-seventh embodiment, as with the twenty-sixth embodiment, is configured such that, in a case in which the cartilage conduction vibration source  925  has a dual purpose for a touch operation in the GUI function of the large-screen display unit  205 , a configuration is presented in that the cartilage conduction vibration source, rather than merely being utilized as a low frequency output element for touch sensation feedback, is additionally used as an impact input element for detecting a touch on the mobile telephone  2401 . For this purpose, the cartilage conduction vibration source  925  in the twenty-seventh embodiment is constituted of a piezoelectric bimorph element. The specific configuration for the dual purpose of the piezoelectric bimorph element as an impact input element can be configured calling on the block diagram of the fourth embodiment described in  FIG. 9  and on the flow chart of the eighteenth embodiment described in  FIG. 31 . 
     More specifically, the GUI function of the large-screen display unit  205  in the twenty-seventh embodiment, as mentioned above, is configured to make use not of a contact-type touch panel, but rather of a motion sensor  2468  for contactless detection of the motion of a finger in the vicinity of the large-screen display unit  205 . The impact detection function of the cartilage conduction vibration source  925 , which comprises a piezoelectric bimorph element, is used as an impact sensor for detecting the touch of a finger (corresponding to the “click” of a mouse or the like) for determining a function that is selected without contact. As a more specific example, scrolling and the selecting of an icon on the large-screen display unit  205  are conducted by the detection of the contactless motion of a finger, and the touch impact on the mobile telephone  2401  corresponding to a “click” operation is detected by the dual purpose of the piezoelectric bimorph element, whereby an operation of “CONFIRM” or “ENTER” is performed. The touch at this time is not on the large-screen display unit  205  but rather may be at any desired place on the outer wall of the mobile telephone, and therefore a “click” operation can be performed without leaving a fingerprint on the large-screen display unit  205 . 
     The vibration isolation material  2465  in the twenty-seventh embodiment, which calls on  FIG. 41 , blocks the vibration from the telephone function unit  45  in the audio signal region, and transmits the transmittable components of the impact vibration in the band-pass filter region or low-pass filter region to the cartilage conduction vibration source  925 , which comprises a piezoelectric bimorph. A point in common with the twenty-sixth embodiment lies in that after the cartilage conduction vibration source  925  detects the touch impact of a finger, a low frequency is generated from the low frequency source  2466  after a predetermined period of delay has passed, and the cartilage conduction vibration source  925  is made to vibrate, providing feedback to the finger that performed the touch. Then, in such a case, there is a need to switch the piezoelectric bimorph element to function as an input element and function as an output element, but this switch can be performed utilizing the aforementioned period of delay. 
     The implementation of the present invention is not to be limited to the aforementioned embodiments; various modification examples are possible. For example, instead of the impact detection function of the piezoelectric bimorph element, the acceleration sensor  49  in  FIG. 42  may be used for detecting the click impact in the contactless-type motion sensor as in the twenty-seventh embodiment. Both the function of the acceleration sensor  49  and the impact detection function of the piezoelectric bimorph element may also be used in combination as appropriate. 
     The dual purpose of the cartilage conduction vibration source  925  as a low frequency vibration source, which is a feature of the twenty-sixth embodiment and the twenty-seventh embodiment, is also not limited to the purpose of providing touch sensation feedback to a finger, but rather can also have the purpose of a dual use as a vibrator for providing a noiseless notification of an incoming call to the mobile telephone  2401 . In such a case, as shall be apparent, the introduction of the vibration signal of the low frequency source  2466  to the cartilage conduction vibration source  925  is not a touch detection but rather a response to an incoming call signal, at which time a delay is unnecessary. The introduction of the vibration signal is repeated continuously (interspersed, for example, by an interval of 0.5 second in which vibration is stopped) for a comparatively long period of time (for example, 2 seconds). 
     Each of the various features indicated in each of the embodiments described above is not necessarily specific to an individual embodiment; the features of each of the embodiments can be combined or rearranged with the features of other embodiments as appropriate, wherever it is possible to make use of the advantages thereof. For example, it is possible to combine the aforementioned eyeglasses-type stereo portable music player described as a modification example of the twenty-fifth embodiment in  FIG. 38 , as an external incoming/outgoing-talk unit for a mobile telephone provided with such features as in the twenty-sixth embodiment or the twenty-seventh embodiment. In such a case, stereo playback from a sound source housed in the music player can be enjoyed, and also audio signals can be received from the sound source of the mobile telephone to enjoy stereo playback. A hands-free call with the mobile telephone can then be made using an air conduction microphone or bone conduction microphone housed in the eyeglasses-type portable music player. 
     Twenty-Eighth Embodiment 
       FIG. 44  relates to the twenty-eighth embodiment according to an aspect of the present invention;  FIG. 44A  is a perspective view illustrating a part of the upper end side thereof, and  FIG. 44B  is a cross-sectional view illustrating the B-B cross-section of  FIG. 44A . The twenty-eighth embodiment is configured as a mobile telephone  2501 , and is similar to the fourth embodiment illustrated in  FIG. 7 ; the vibration of a cartilage conduction vibration source  2525  is transmitted to a vibration conductor  2527 , the two end parts thereof being in respective contact with the right tragus and the left tragus, whereby sound can be listened to by cartilage conduction. Accordingly, the “upper part” in the twenty-eighth embodiment of  FIG. 44  does not signify a separated upper part but rather signifies the portion at the top of the integrated structure. 
     A point of difference in the twenty-eighth embodiment of  FIG. 44  from the fourth embodiment illustrated in  FIG. 7  lies in the holding structure for holding the cartilage conduction vibration source  2525  and the vibration conductor  2527  in the mobile telephone  2501 . For the configuration for inputting an audio signal into the cartilage conduction vibration source  2525  and the like there can be appropriately used the configuration according to the first to twenty-seventh embodiments, and therefore an illustration and description thereof has been omitted. The cartilage conduction vibration source  2525  of the twenty-eighth embodiment is configured as a piezoelectric bimorph element (and is hereinafter referred to as the “piezoelectric bimorph element  2525 ”), but, as in  FIG. 44B , the structure piezoelectric bimorph element  2525  is one in which piezoelectric ceramic sheets  2598 ,  2599  are respectively bonded to the two sides of a metal sheet  2597 , the circumference thereof being hardened using a resin. Vibration in this structure goes in the Y-Y′ direction illustrated in  FIG. 44B . Accordingly, the resin surface of the piezoelectric bimorph element  2525  has a larger Y-Y′ direction component of vibration, and a smaller X-X′ direction component of vibration. 
     Assuming the above-described structure for the piezoelectric bimorph element  2525 , the holding structure of the twenty-eighth embodiment is such that, as is clear from the cross-sectional view of  FIG. 44B , the piezoelectric bimorph element  2525  is sandwiched from the X-X′ direction, which has a smaller vibration component, by a holding body  2516 . The holding body  2516  and the piezoelectric bimorph element  2525  are joined using a bonding agent, and the holding body  2516  is rigidly coupled to the mobile telephone  2501 . On the other hand, regarding the Y-Y′ direction of the piezoelectric bimorph element  2525 , a gap  2504  is provided in  FIG. 44B  in between the holding body  2516  and the inner surface side serving as the right side; vibration is unrestrictedly permitted in the Y-Y′ direction in the piezoelectric bimorph element  2525 , and the vibration component therein is less likely to be transmitted to the holding body  2516 . A bonding agent is also used to join the vibration conductor  2527  rigidly to the outer surface side serving as the left side in  FIG. 44B  in the Y-Y′ direction of the piezoelectric bimorph element  2525 . The mobile telephone  2501  also has an opening part  2501   a  for exposing the vibration conductor  2527 . Then, the vibration isolation material  2565  comprising an elastic body based on vinyl, urethane, or another substance is used to fill in the space between the vibration conductor  2527  and the holding body  2516 , and the opening part  2501   a  of the mobile telephone  2501 . Vibration is unrestrictedly permitted in the Y-Y′ direction of the vibration conductor  2527 , and the vibration component of the piezoelectric bimorph element  2525  is less likely to be transmitted to the holding body  2516  and the mobile telephone  2501 . In the description above, the gap  2504  may also be configured so as to be filled in by an elastic body similar to the vibration isolation material  2565 . 
     Due to the holding structure as described above, the force of the hand holding the mobile telephone  2501  is rigidly applied to the vibration conductor  2527 , whereby the contact with the right tragus or left tragus and the pressure thereof can be easily controlled. Because the structure is such that vibration is unrestrictedly permitted in the Y-Y′ direction of the vibration conductor  2527 , the vibration conductor  2527  vibrates efficiently and the vibration thereof is transmitted to the cartilage of the ear; also, the vibration of the vibration conductor  2527  can be effectively prevented from being transmitted to the mobile telephone  2501  and generating unneeded air conduction. 
       FIG. 45  is a cross-sectional view relating to modification examples of the twenty-eighth embodiment of  FIG. 44 .  FIG. 45A  is a cross-sectional view of a first modification example, and is illustrated in conformity with  FIG. 44B , portions in common being given like reference numerals. Similarly,  FIG. 45B  illustrates a cross-sectional view of a second modification example. In the first modification example, illustrated by  FIG. 45A , the gap  2504  is stretched over the entire space between the holding body  2516  and the piezoelectric bimorph element  2525 , and an auxiliary holding unit  2506  for holding the piezoelectric bimorph element  2525  between the two from the X-X′ direction is provided. The rigid material of the auxiliary holding unit  2506  is selected to have a different acoustic impedance from either both of or at least one of the holding body  2516  and the piezoelectric bimorph element  2525 . The auxiliary holding unit  2506  may be an elastic body provided that there is no problem in terms of holding force. The auxiliary holding unit  2506  is configured to be arranged at the center part to avoid the vibration surface of the Y-Y′ direction in the piezoelectric bimorph element  2525 ; therefore, even with an integrated molding of the same material, as a part of the holding body  2516 , there is a more pronounced effect relative to  FIG. 44(B)  in permitting vibration in the Y-Y′ direction in the piezoelectric bimorph element  2525  and in reducing the transmission of vibration to the mobile telephone  2501 . 
     The second modification example of  FIG. 45B  also takes a configuration in which the gap  2504  is spread over the entire space between the holding body  2516  and the piezoelectric bimorph element  2525 ; however, a plurality of screws  2508  provided to important points in the middle part of the piezoelectric bimorph element  2525  are used to sandwich the piezoelectric bimorph element  2525  from the X-X′ direction. The screws  2508  are threaded such that the sharp tips thereof are slightly wedged into the surface of the piezoelectric bimorph element  2525 , ensuring the holding of the piezoelectric bimorph element  2525 . 
       FIG. 46  is a cross-sectional view relating to yet further modification examples of the twenty-eighth embodiment of  FIG. 44 .  FIG. 46A  is a cross-sectional view of a third modification example, and, similarly with respect to  FIG. 45 , is illustrated in conformity with  FIG. 44B , shared portions being given shared reference numerals. Similarly,  FIG. 46B  illustrates a cross-sectional view of a fourth modification example. In the third modification example illustrated in  FIG. 46A , the surface of the piezoelectric bimorph element  2525  is molded using a resin such that a concavity  2580  is formed, and a convexity corresponding thereto is integrally molded in the holding body  2516 . The engagement between these convex and concave parts ensures that the piezoelectric bimorph element  2525  is held by the holding body  2516 . Upon assembly, the slight elasticity of the holding body  2516  may be utilized for fitting of the piezoelectric bimorph element  2525 ; alternatively, the configuration may be such that the holding body  2516  is constituted as two divided bodies, and after the piezoelectric bimorph element  2525  is sandwiched therebetween, same are integrally screwed together. 
     In the fourth modification example illustrated by  FIG. 46B , the surface of the piezoelectric bimorph element  2525  is molded with a resin such that a convexity  2590  is formed, and a concavity corresponding thereto is integrally molded in the holding body  2516 . Then, similarly with respect to  FIG. 46A , the engagement of these convex and concave parts ensures the holding of the piezoelectric bimorph element  2525  by the holding body  2516 . Upon assembly, similarly with respect to  FIG. 46A , the configuration may be such that the piezoelectric bimorph element  2525  may be fitted using the slight elasticity of the holding body  2516 , or such that the holding body  2516  is constituted as two divided bodies, and after the piezoelectric bimorph element  2525  is sandwiched therebetween, the same are integrally screwed together. 
     Twenty-Ninth Embodiment 
       FIG. 47  relates to the twenty-ninth embodiment according to an aspect of the present invention;  FIG. 47A  is a perspective view illustrating a part of the upper end side thereof, and  FIG. 47B  is a perspective view illustrating a part of the upper end side in a modification example thereof. The twenty-ninth embodiment has a holding structure that is substantially the same as that of the twenty-eighth embodiment in  FIG. 44 , but has a different configuration, in which the vibration conductor in contact with the right tragus or the left tragus is exposed to the surface of the mobile telephone from openings  2501   b  and  2501   c  provided to the outer wall of the mobile telephone  2501 . Portions in common with  FIG. 44  are accordingly given the same reference numerals, and a description thereof has been omitted. The following provides only a description of the disparities relative to the twenty-eighth embodiment of  FIG. 44 . 
     The twenty-eighth embodiment of  FIG. 44  is configured such that the vibration conductor  2527  is exposed in a strip on the entire upper end part of the mobile telephone  2501 , both end parts thereof being in contact with the right tragus and left tragus respectively and also being capable of being in contact with the ear cartilage over a broad surface area. By contrast, the twenty-ninth embodiment of  FIG. 47A  is configured such that the vibration conductor is divided into a right ear vibration conductor  2524  and a left ear vibration conductor  2526 , which are respectively bonded to the two ends of the piezoelectric bimorph element  2525 . Then, only a portion of the separated right ear vibration conductor  2524  and left ear vibration conductor  2526  is made to be respectively exposed from the opening parts  2501   b  and  2501   c  of the two corner parts at the top end of the mobile telephone  2501 . For this reason, the vibration isolation material  2565  for filling in the space between the mobile telephone  2501  and the right ear vibration conductor  2524  and left ear vibration conductor  2526  is also provided in respective separations. 
     On the other hand, the modification example of the twenty-ninth modification example illustrated by  FIG. 47B  is configured such that only the left ear vibration conductor  2526  is bonded to the piezoelectric bimorph element  2525 . Then, only a portion of the left ear vibration conductor  2526  is exposed from the opening part  2501   b  of the corner part at the top end of the mobile telephone  2501 . The vibration isolation material  2565  for filling in the space between the left ear vibration conductor  2526  and the mobile telephone  2501  is provided only to the left side corner part of the mobile telephone  2501 . Also, the modification example of the twenty-ninth embodiment illustrated by  FIG. 47B , although simplifying the configuration of  FIG. 47A  and being configured for dedicated left ear usage, is also capable of being configured such that the vibration conductor is exposed from an opening part provided to the right corner part for a configuration as a mobile telephone especially for right ear usage. As yet another modification of the modification example of the twenty-ninth embodiment illustrated by  FIG. 47B , the piezoelectric bimorph element can also be directly exposed from the opening part, without the vibration conductor being interposed, in a case in which the surface of the piezoelectric bimorph element is fashioned into a shape suited for the outer surface of the mobile telephone. Such a modification is also possible in the twenty-ninth embodiment illustrated by  FIG. 47A  and in the twenty-eighth embodiment illustrated by  FIG. 44 . 
     Thirtieth Embodiment 
       FIG. 48  relates to the thirtieth embodiment according to an aspect of the present invention;  FIG. 48A  is a perspective view illustrating a part of the upper end side thereof, and  FIG. 48B  is a cross-sectional view illustrating the B-B cross-section of  FIG. 48A . The thirtieth embodiment is configured as a mobile telephone  2601  and is similar to the thirteenth embodiment illustrated by  FIG. 24  and/or the fourteenth embodiment illustrated by  FIG. 25 . The cartilage conduction vibration unit is arranged on the side surface of the mobile telephone. The thirtieth embodiment of  FIG. 48 , similarly with respect to the twenty-eighth embodiment of  FIG. 44 , also features a holding structure for permitting vibration for ear cartilage conduction in the piezoelectric bimorph element and for reducing the transmission of vibration to the mobile telephone; therefore, portions in common with the twenty-eighth embodiment have been given like reference numerals, and a description thereof has been omitted. Another point of similarity with the twenty-eighth embodiment lies in the configuration for inputting an audio signal to the cartilage conduction vibration source  2525 , of which a depiction and description has been omitted. 
     The thirtieth embodiment of  FIG. 48  is configured such that the piezoelectric bimorph element  2525  is fitted into the side surface of the mobile telephone, but, as illustrated by  FIG. 48B , the interior of the fitted-in part is curved; as a result thereof, a ridge part  2525   a  of the piezoelectric bimorph element  2525  is brought into contact with the inner surface of the curved part of the mobile telephone  2601 . Due to such contact, the piezoelectric bimorph element  2525  is positioned in the fitting-depth direction, reinforcing the holding force relative to the direction pushing in on the piezoelectric bimorph element  2525 . A crescent gap  2604  is created in the Y-Y′ direction of the piezoelectric bimorph element  2525  due to the contact structure as described above, permitting free vibration. The piezoelectric bimorph element  2525  is fundamentally held from the X-X′ direction in the thirtieth embodiment as well. For the sake of simplicity, the illustration in  FIG. 48  is such that a part of the integral structure of the mobile telephone  2601  serves as the holding structure, but the configuration may also be such that a structure such as the holding body  2516  of the twenty-eighth embodiment and of the twenty-ninth embodiment is utilized, and anchored on the mobile telephone  2601 . The structure can otherwise be understood with reference to  FIG. 44 , and therefore a description thereof has been omitted. The various modification examples illustrated in  FIGS. 45 and 46  can also be applied to the thirtieth embodiment of  FIG. 48 . 
     Thirty-First Embodiment 
       FIG. 49  relates to a thirty-first embodiment according to an aspect of the present invention;  FIG. 49A  is a longitudinal sectional view illustrating a part of the upper end side thereof.  FIG. 49B  is a transverse cross-sectional view of the same portions, and can be understood to be similar to  FIG. 48B . The thirty-first embodiment is configured as a mobile telephone  2701 , and is similar to the thirtieth embodiment illustrated in  FIG. 48 ; the cartilage conduction vibration unit is arranged on the side surface of the mobile telephone. The feature thereof lies in the holding structure for permitting vibration for ear cartilage conduction in the piezoelectric bimorph element and for reducing the transmission of vibration to the mobile telephone; therefore, portions in common with the thirtieth embodiment of  FIG. 48  have been given like reference numerals, and a description thereof has been omitted. Another point of similarity with the thirtieth embodiment lies in the configuration for inputting an audio signal to the cartilage conduction vibration source  2525  and the like, for which a depiction and description has been omitted. 
     A point of difference in the thirty-first embodiment of  FIG. 49  from the thirtieth embodiment of  FIG. 48  lies in the holding structure of the piezoelectric bimorph element  2525 . The piezoelectric bimorph element  2525 , similarly with respect to the thirtieth embodiment, takes a structure in which it is fitted into a groove in the side surface of the mobile telephone  2701 , but as is clear from the longitudinal cross-sectional view of  FIG. 49A  and the transverse cross-sectional view of  FIG. 49B , the inner surface of the groove becomes a corrugated surface  2794 ; as a result thereof, the piezoelectric bimorph element  2525  is held by a plurality of apices of the corrugated surface  2794 , and a plurality of gaps  2704  are created in between the two. For the sake of simplicity, the illustration in  FIG. 49  is also such that a part of the integral structure of the mobile telephone  2701  serves as the holding structure, but the configuration may also be one in which there is adopted a structure such as the holding body  2516  of the twenty-eighth embodiment and of the twenty-ninth embodiment, and same is anchored to the mobile telephone  2701 . This is also a point of similarity with modification examples to be described later. 
       FIG. 50  is a longitudinal cross-sectional view illustrating modification examples of the thirty-first embodiment, and can be understood with reference to  FIG. 49A .  FIG. 50A  is a first modification example, wherein a vibration conductor  2727  (silicon, urethane, or the like) is provided to the side of the piezoelectric bimorph element  2525  that comes up against the ear cartilage.  FIG. 50B  is a second modification example. A vibration isolation material  2765  is interposed between the piezoelectric bimorph element  2525  and the mobile telephone  2701 , and the surface at which the vibration isolation material  2765  comes up against the piezoelectric bimorph element  2525  serves as the corrugated surface  2795 . A modification example that combines the vibration conductor  2727  in the first modification example of  FIG. 50A  with the vibration isolation material  2765  in the second modification example of  FIG. 50B  is also possible. 
     Thirty-Second Embodiment 
       FIG. 51  is a perspective view of a thirty-second embodiment according to an aspect of the present invention. The thirty-second embodiment is configured as a piezoelectric bimorph element  2525  suited for use in, for example, the mobile telephone  2501  of the twenty-ninth embodiment illustrated in  FIG. 47A .  FIG. 51A  is an external perspective view of the piezoelectric bimorph element  2525  of the thirty-second embodiment, and  FIG. 51B  is a transparent perspective view thereof. For convenience of illustration,  FIG. 51  has been drafted such that the piezoelectric bimorph element  2525  is rotated 90 degrees from the state of  FIG. 47A , where the Y-Y′ direction becomes the vertical direction. 
     The holding body  2516  of the twenty-ninth embodiment of  FIG. 47A , similarly with respect to that of the twenty-eighth embodiment of  FIG. 44 , sandwiches the piezoelectric bimorph element  2525  from the X-X′ direction illustrated in  FIG. 44B ; vibration in the Y-Y′ direction is unrestrictedly permitted, and the vibration component is prevented from being transmitted to the holding body  2516 . Furthermore, the holding body  2516  is configured so as to sandwich the middle portion of the piezoelectric bimorph element  2525 , in which the right ear vibration conductor  2524  and the left ear vibration conductor  2526  are respectively bonded to both ends. 
     The piezoelectric bimorph element  2525  illustrated in  FIG. 51  assumes a configuration permitting the holding of the middle part of the piezoelectric bimorph element  2525  from the X-X′ direction, as described above. Specifically, as illustrated in  FIG. 51A , the piezoelectric bimorph element  2525  of the thirty-second embodiment is configured such that electrodes  2597   a  and  2598   a  for inputting a drive signal are positioned at the middle portion of the piezoelectric bimorph element  2525 . Both end portions of the piezoelectric bimorph element  2525  are thereby released from a wired connection, and free vibration is permitted. Moreover, the direction in which the electrodes  2597   a  and  2598   a  project out is configured so as to assume a direction along the Y-Y′ direction of the vibration direction. Thereby, when the middle portion of the piezoelectric bimorph element  2525  is sandwiched from the X-X′ direction, the electrodes  2597   a  and  2598   a  are not obstructive and there is no need to provide the holding body  2516  with a special configuration, despite the arrangement of the electrodes  2597   a  and  2598   a  at the middle portion. 
     To permit such an arrangement of the electrodes, the piezoelectric bimorph element  2525  is configured, as illustrated in  FIG. 51B , such that the electrode  2597   a , which is drawn out from the middle portion of a metal sheet  2597 , is curved upward at 90 degrees, and the electrodes  2598   a , which are drawn out from piezoelectric ceramic sheets  2598  and  2599 , and respectively connected to each one, are also curved upward at 90 degrees, each projecting from the upper surface of the resin. The middle portion of the piezoelectric bimorph element  2525  can thereby be readily supported sandwiched from the X-X′ direction, without an electrode projecting out to the X-X′ direction. 
     Also, as a modification of  FIG. 51 , the configuration can also be such that each of the electrode  2597   a  that is drawn out from the middle part of the metal sheet  2597  and the electrodes  2598   a  that are drawn out from the middle parts of the piezoelectric ceramic sheets  2598  and  2599  project out from the side surface of the resin. In such a case, to sandwich and support the middle portion of the piezoelectric bimorph element  2525  from the X-X′ direction, the holding body  2516  is provided with a void for avoiding a portion that would interfere with the electrodes, and connects a signal line; alternatively, a socket structure is provided to the inner side of the holding body  2516  and a connection is made with the electrodes. In such a case as well, the holding body  2516  must be provided with a special configuration; however, no change is needed to provide the electrodes  2597   a  and  2598   a  to the middle part, and therefore it is possible to benefit from the advantage of releasing the two end portions of the piezoelectric bimorph element  2525  from wired connections and enabling free vibration. 
     Thirty-Third Embodiment 
       FIG. 52  relates to a thirty-third embodiment according to an aspect of the present invention, and is configured as a mobile telephone  2801 .  FIG. 52A  is a transparent perspective view in which a part of the upper end side thereof is viewed from the rear, and  FIG. 52B  is a transparent perspective view in which a part of the upper end side in the modification example thereof is viewed from the side surface of the opposite side. The thirty-third embodiment illustrated in  FIG. 52A  has a holding structure that is substantially similar to that of the twenty-ninth embodiment in  FIG. 47A , but has a different configuration in which a pair of vibration conductors  2824  and  2826  that are in contact with the ear cartilage are exposed on the surface of the mobile telephone. 
     Specifically, the vibration conductors  2524  and  2526  in the twenty-ninth embodiment of  FIG. 47  are directly exposed at the upper corner parts of the mobile telephone  2501 . By contrast, in the thirty-third embodiment of  FIG. 52 , corner parts  2801   d ,  2801   e  serve as a part of a sufficiently strong outer wall of the mobile telephone  2801  itself, and each of the vibration conductors  2824  and  2826  are exposed on the display surface side of the mobile telephone  2801  in such as form as to be guarded by the corner parts. A detailed description of this exposed state and the significance thereof will be provided later. The configuration is otherwise shared with that of the twenty-ninth embodiment of  FIG. 47 ; therefore, in  FIG. 52  portions that are in common have been given like reference numerals, and a description thereof has been omitted. The thirty-third embodiment also serves as an example of the implementation of the piezoelectric bimorph elements  2525  illustrated in the thirty-second embodiment, and also illustrates the positions of the electrodes  2597   a  and  2598   a  together. 
     In the modification example of the thirty-third embodiment in  FIG. 52B , the same configuration as the vibration unit described with reference to  FIG. 52A  is attached such that the side surface of the mobile telephone  2801  is made to vibrate as in the thirtieth embodiment of  FIG. 48  and/or the thirty-first embodiment of  FIG. 49 . In the modification example of the thirty-third embodiment in  FIG. 52B  as well, the vibration conductor  2824 , which is the upper of the pair of vibration conductors, is guarded by the sufficiently strong corner part  2801   d  of the mobile telephone  2801  and is exposed to the side surface of the mobile telephone  2801 . The vibration conductor  2826 , which is lower, is not originally positioned at a corner part and is therefore guarded naturally. 
       FIG. 53  is an external perspective view in which each of the thirty-third embodiment of  FIG. 52  and the modification example thereof is viewed from the front;  FIG. 53A  belongs to the thirty-third embodiment, and  FIG. 53B  belongs to the modification example thereof. The configuration in  FIG. 53  also has much in common with the twenty-sixth embodiment of  FIG. 41  and the like; therefore, portions that are in common have been given like reference numerals, and a description thereof has been omitted. 
     As is clear from  FIG. 53A , a pair of vibration conductors  2824  and  2826  are respectively exposed on the surface of the large-screen display unit  205  of a mobile telephone  2801  in such a form as to be respectively guarded by the corner parts  2801   d  and  2801   e  of the mobile telephone  2801 . Similarly with respect to the twenty-ninth embodiment of  FIG. 47 , a vibration isolation material  2865  is also used in the thirty-third embodiment of  FIG. 53A  to fill in the space between the pair of vibration conductors  2824  and  2826  and the mobile telephone  2801 . 
     Herein, a description will be provided for the significance of the aforementioned configuration of the thirty-third embodiment illustrated in  FIGS. 52 and 53 . The corner parts  2801   d  and  2801   e  of the mobile telephone  2801  are at sites that are suitable for coming up against the tragus or other ear cartilage, but are simultaneously also at sites that facilitate the direct application of impact when a drop or other event occurs. Accordingly, in a case assuming a configuration such as, for example, that of the twenty-ninth embodiment of  FIG. 47 , the vibration conductors  2524  and  2526 , the piezoelectric bimorph element  2525  to which same are bonded, the holding body  2516  thereof, and other vibration units must have a configuration that is resilient against collision. By contrast, according to the configuration of the thirty-third embodiment illustrated in  FIGS. 52 and 53 , the vibration conductors  2524  and  2526  are guarded by the original corner parts  2801   d  and  2801   e  of the mobile telephone  2801 ; therefore, a countermeasure for impacts is more readily realized than in the case of the twenty-ninth embodiment. 
     In the modification example of  FIG. 53B  as well, as is clear from the diagram, the vibration conductor  2824 , which is the upper of the pair of vibration conductors, is guarded by the corner part  2801   d  of the mobile telephone  2801  and is exposed to the side surface of the mobile telephone  2801 . The vibration conductor  2826 , which is lower, is positioned at a side surface that is less prone to the direct application of impact. Similarly with respect to the case of  FIG. 53A , the vibration isolation material  2865  is used to fill in the spaces between the pair of vibration conductors  2824  and  2826  and the mobile telephone  2801 . 
     In a case in which, as in the modification examples of the thirty-third embodiment illustrated in  FIGS. 52B and 53B , the vibration conductors  2824  and  2826  are provided to two points on the side surface (one point of which is in the vicinity of the upper part corner  2801 ), it becomes possible for both to come up against two points of the ear cartilage in the longitudinal direction. In such a case, when the space between the vibration conductor  2824  and the vibration conductor  2826  is on the order of 2 to 5 cm, the upper vibration conductor  2824  is also able to come up against the ear cartilage when the lower vibration conductor  2826  comes up against the tragus. As shall be apparent, the use such that the upper vibration conductor  2824  is brought up against the tragus for listening is discretionary. Similarly, in the case of the thirty-third embodiment illustrated in  FIGS. 52A and 53A  as well, the vibration conductors  2824  and  2826  can also be brought up against two points of the ear cartilage in the transverse direction. The divided use of the vibration conductor  2824  for abutting the right tragus and of the vibration conductor  2826  for abutting the right tragus, such as in the twenty-ninth embodiment of  FIG. 47 , is also discretionary. 
     In any event, abutting the ear cartilage at two points permits the energies of both the simultaneously vibrating vibration conductors  2824  and  2826  to be introduced to the ear cartilage; the transmission is therefore energy-efficient. On the other hand, in a case in which the mobile telephone  2801  is pushed strongly against the tragus to obtain the earplug bone conduction effect, the pushing on and obstructing of the tragus is more readily achieved by bringing merely a single vibration conductor at the corner part up against the tragus. 
     Thirty-Fourth Embodiment 
       FIG. 54  is a transparent perspective view relating to a thirty-fourth embodiment according to an aspect of the present invention, the embodiment being configured as a mobile telephone  2901 . The thirty-fourth embodiment is configured such that the side surface of the a mobile telephone  2901  is made to vibrate, as in the thirtieth embodiment of  FIG. 48  and/or the thirty-first embodiment of  FIG. 49 , but both side surfaces are made to be capable of vibrating so as to be able to support both the case of right-hand-held and the case of left-hand-held usage. In other words, the thirty-fourth embodiment of  FIG. 54  substitutes the pair of vibration conductors  2824  and  2826  in the thirty-third embodiment of  FIG. 52A  with a pair of vibration conductors  2924  and  2926  for a side surface arrangement; the vibration conductors  2924  and  2926  assume a vertically long shape so as to achieve contact with the ear cartilage over a broad range of the side surface. The holding structure of the piezoelectric bimorph element  2525  is shared with that of the thirty-third embodiment of  FIG. 52A , but a more detailed illustration has been omitted in order to avoid complication. 
     In the thirty-fourth embodiment, the color of the vibration conductors  2924  and  2926  is made to be different from the color of the outer wall of the mobile telephone  2901 , and the configuration may also be such that the user knows that the configuration is such that sound is listened to from the side surface and also knows what portion is thereupon brought up against the ear. On the other hand, in a case in which the user is notified that the configuration is such that sound is listened to from the side surface and what portion is thereupon brought up against the ear, there may be employed a design for implementing surface processing such that it is unknown whether the color of the vibration conductors  2924  and  2926  has been rendered as the same color as the color of the outer wall of the mobile telephone  2901 , and such that the boundary with the outer wall of the mobile telephone  2901  is further unknown. The configuration of the thirty-fourth embodiment is otherwise shared with that of, for example, the twenty-sixth embodiment of  FIG. 41 , and therefore portions that are in common have been given like reference numerals, and a description thereof has been omitted. 
     Thirty-Fifth Embodiment 
       FIG. 55  is a transparent perspective view relating to a thirty-fifth embodiment according to an aspect of the present invention, the embodiment being configured as a mobile telephone  3001 . The thirty-fifth embodiment is also configured such that the two side surfaces of the mobile telephone  3001  are made to vibrate across a broad range, similarly with respect to the thirty-fourth embodiment of  FIG. 54 . However, a point of difference from the thirty-fourth embodiment of  FIG. 54  lies in that a pair of piezoelectric bimorph elements  3024  and  3026  are arranged in a vertically long position such that each of the two side surfaces can be independently controlled. It accordingly becomes possible to cause only the one piezoelectric bimorph element that is being used to vibrate automatically, similarly with respect to the first to third embodiments described in  FIGS. 1 to 6 . The holding of the piezoelectric bimorph elements  3024  and  3026  can utilize the holding structures in each of the embodiments described in  FIGS. 44 to 52  and the like, as appropriate, and therefore a more detailed illustration has been omitted in order to avoid complexity. 
     The thirty-fifth embodiment may also be configured such that, when the piezoelectric bimorph elements  3024  and  3026  are arranged on the side surfaces, the piezoelectric bimorph elements  3024  and  3026  are covered with a material such as that of the vibration conductor  2527  in the thirtieth embodiment in  FIG. 48 , the color of the vibration conductor being made to be different from the color of the outer wall of the mobile telephone  3001 , such that the user learns that the configuration is such that sound is listened to from the side surface and knows what portion is thereupon brought against the ear. On the other hand, similarly with respect to the thirty-fifth embodiment, in a case in which the user is notified that the configuration is such that sound is listened to from the side surface and is notified of what portion is thereupon brought up against the ear, there may be employed a design for implementing surface processing such that it is unknown whether the color of the vibration conductor has been rendered as the same color as the color of the outer wall of the mobile telephone  3001 , and such that the boundary with the other side surface portion in the outer wall of the mobile telephone  3001  is unknown. The configuration of the thirty-fifth embodiment is otherwise shared with that of, for example, the twenty-sixth embodiment of  FIG. 41 , and therefore portions that are in common have been given like reference numerals, and a description thereof has been omitted. 
     Thirty-Sixth Embodiment 
       FIG. 56  is a transparent perspective view relating to a thirty-sixth embodiment according to an aspect of the present invention, and is configured as a mobile telephone  3101  and a mobile telephone  3201 . The configuration of the thirty-sixth embodiment of  FIG. 56  is substantially consistent with that of the thirty-fifth embodiment of  FIG. 55 , but the mobile telephone is configured as a left-handed mobile telephone  3101  illustrated in  FIG. 56A  and as a right-handed mobile telephone  3201  illustrated in  FIG. 56B  so as to provide the market with the ability to select either one. In other words, the left-handed mobile telephone  3101  of  FIG. 56A  is provided with a piezoelectric bimorph element  3024  for coming up against the left tragus, and the right-handed mobile telephone  3201  illustrated in  FIG. 56B  is provided with a piezoelectric bimorph element  3026  for coming up against the left tragus. Since usage is limited to a single side, for microphones and other outgoing-talk units, the left-handed mobile telephone  3101  of  FIG. 56A  is provided with an outgoing-talk unit (microphone)  1223  at the bottom of the left side surface, and the right-handed mobile telephone  3201  of  FIG. 56B  is provided with an outgoing-talk unit (microphone)  1123  at the bottom of the right side surface. The outgoing-talk units (microphones)  1123  or  1223  are similar to those of the twelfth embodiment or the thirteenth embodiment; during a videoconferencing function in which the large-screen display unit  205  is being observed, the outgoing-talk units (microphones)  1123  and  1223 , which serve as outgoing-talk units, are switched, and are able to pick up audio uttered by the user while the large-screen display unit  205  is being observed. 
     In the thirty-sixth embodiment of  FIG. 56 , as described above, the piezoelectric bimorph elements and/or microphones and other audio-related configurations relating to listening and speaking are integrated at the side surface of the mobile telephone; and the visual-related configuration of the large-screen display unit  205  and the like is integrated at the front surface of the mobile telephone. Therefore, as the side surface is used when the mobile telephone  3101  or  3201  is brought up against the face at the ear or the like and the front surface is used when the mobile telephone  3101  or  3201  is being watched with the eyes, the two surfaces of the mobile telephone  3101  or  3201  describing a 90° angle can be used separately, and the front surface of the mobile telephone  3101  or  3201  can be prevented from having the display surface  205  or the like fouled by the face. 
     In the thirty-sixth embodiment of  FIG. 56 , the side surface that is the opposite side at which the piezoelectric bimorph element  3024  or  3026  is not arranged is primarily used to hold the mobile telephone, and therefore, in a natural manner of holding with the hands, the side surface is covered with a material  3101   f  or  3201   f  that is rough to the touch, facilitating holding and also permitting a clear understanding of which side is brought up against the ear. The thirty-sixth embodiment, similarly with respect to the thirty-fifth embodiment, may also be configured such that the color of the vibration conductor for covering the piezoelectric bimorph element  3024  or  3026  is different from the color of the outer wall of the mobile telephone  3101  or  3201 . In a case in which the side surface of the opposite side in the thirty-sixth embodiment is covered with the material  3101   f  or  3201   f  that is rough to the touch, as described above, then the side surface of the side for listening to sound can be recognized, and accordingly there may be employed a design for implementing surface processing such that it is unknown whether the color of the vibration conductor has been rendered as the same color as the color of the outer wall of the mobile telephone  3101  or  3201 , and such that the boundary with the other side surface portion in the outer wall of the mobile telephone  3101  or  3201  is further unknown. The configuration of the thirty-fifth embodiment is otherwise shared with that of, for example, the twenty-sixth embodiment of  FIG. 41 , and therefore portions that are in common have been given like reference numerals, and a description thereof has been omitted. 
     However, the terms “right-handed” and “left-handed” in the thirty-sixth embodiment anticipate, for example, a state in which the side surface to which the piezoelectric bimorph element  3024  is provided comes up against the left ear cartilage when the side surface of the mobile telephone  3101  comes up against the ear, without the wrist being turned, directly out of the state in which the mobile telephone  3101  of  FIG. 56A  is held with the left hand and the display surface  205  is viewed. However, the user&#39;s method of use is discretionary; when the wrist is rotated 180° to turn the mobile telephone  3101  of  FIG. 56A  over when the mobile telephone  3101  is held in the right hand and brought up against the ear, the side surface of the side to which the piezoelectric bimorph element  3024  is provided can be brought up against the right ear cartilage. Accordingly, the terms “right-handed” and “left-handed” are merely provisional; the user is capable of purchasing either one and unrestrictedly selecting how to use same. The mobile telephone  3101  of  FIG. 56A  can accordingly be identified as being “right-handed” for a user who turns the wrist for use in the manner described above. 
     Thirty-Seventh Embodiment 
       FIG. 57  is a transparent perspective view relating to a thirty-seventh embodiment according to an aspect of the present invention, and is configured as a mobile telephone  3301 . The thirty-seventh embodiment of  FIG. 57  has many portions in common with the modification example of the tenth embodiment in  FIG. 40 ; therefore, portions in common have been given like reference numerals, and a description thereof has been omitted. A point of difference in the thirty-seventh embodiment from the modification example of the tenth embodiment lies in that the piezoelectric bimorph element  2525  is covered with a cartilage conduction output unit  3363 , in which not only the front surface but also the upper side and the front, rear, left, and right sides at the top edge of the mobile telephone  3301  are formed of a material having an acoustic impedance approximating that of ear cartilage. This cartilage conduction output unit  3363 , similarly with respect to the cartilage conduction output unit  963  in the tenth embodiment or in the modification example thereof, is formed using, for example, a silicone rubber; a mixture of a silicone rubber and a butadiene rubber; a natural rubber; or a material having a structure formed using these varieties of rubber in which air bubbles are sealed. 
     According to the configuration of the thirty-seventh embodiment, cartilage conduction can be obtained by any site anywhere on the top of the mobile telephone  3301  coming up against ear cartilage; therefore, sound can be listened to at an optimal volume merely by bringing the top part of the mobile telephone  3301  up against the ear, regardless of the location thereon. 
     The various features of each of the embodiments described above are not to be restricted to individual respective embodiments; they can be substituted or combined with other appropriate embodiments. 
     Thirty-Eighth Embodiment 
       FIG. 58  is a cross-sectional block diagram relating to a thirty-eighth embodiment according to an aspect of the present invention, and is configured as a mobile telephone  3401 . The thirty-eighth embodiment of  FIG. 58  shares many portions with the twenty-sixth embodiment or the twenty-seventh embodiment, and therefore portions that are in common have been given the same reference numerals as in  FIG. 42  and a description thereof has been omitted. A point of difference in the thirty-eighth embodiment from the twenty-sixth embodiment or from the twenty-seventh embodiment lies in it being configured such that the cartilage conduction vibration source  2525 , which is constituted of a piezoelectric bimorph element, is anchored to a chassis structure  3426  of the mobile telephone  3401 , and the vibration of the cartilage conduction vibration source  2525  is transmitted to the entire surface of the mobile telephone  3401 . In anchoring the piezoelectric bimorph element constituting the cartilage conduction vibration source  2525 , to actively transmit the vibration thereof, the gap  2504  such as in  FIG. 44B  is not provided, but rather there is a close bond to the chassis structure  3426 , and the vibration in the primary vibration direction (the Y-Y′ direction) is likely to be transmitted to the chassis structure  3426 . The entire surface of the mobile telephone  3401  thereby acts as a vibration conductor, and cartilage conduction can be obtained regardless of what location on the surface of the mobile telephone  3401  is brought up against the ear cartilage. 
     Because the thirty-eighth embodiment has the aforementioned configuration, in a case in which a large portion of the surface area of the front surface or the back surface of the mobile telephone  3401  is brought up against the entire cartilage of the ear, similarly with respect to the fifth to ninth embodiments, the vibration of the cartilage conduction vibration source  2525  is transmitted to the ear cartilage over a broad contacted surface area of the surface of the mobile telephone  3401  via the chassis structure  3426 . Air conduction sound that is generated by the vibration of the surface of the mobile telephone  3401  is also transmitted from the external auditory meatus to the tympanic membrane. Sound source information from the cartilage conduction vibration source  2525  can thereby be heard as a loud sound. The surface of the mobile telephone  3401  that is brought up against the ear assumes a form such that the external auditory meatus is obstructed, and therefore environment noise can be blocked. Increasing the force pushing the mobile telephone  3401  against the ear furthermore gives the result of substantially completely obstructing the external auditory meatus, and sound source information from the cartilage conduction vibration source  2525  can be heard as an even louder sound due to the earplug bone conduction effect. 
     In a case in which the side surface of the thirty-eighth embodiment is brought up against the ear cartilage, then the front surface of the mobile telephone to which the display surface and the like are provided can be prevented from being fouled by contact with the face, similarly with respect to the eleventh to fourteenth embodiments, the thirtieth embodiment, the thirty-first embodiment, the modification example of the thirty-third embodiment, and the thirty-fourth to thirty-sixth embodiments. Furthermore, in a case in which the upper edge corner of the thirty-eighth embodiment is brought up against the ear cartilage, contact with the tragus is readily achieved, and pushing on the tragus to obstruct the external auditory meatus can readily obtain the earplug bone conduction effect, similarly with respect to the first to fourth embodiments, the tenth embodiment and the modification example thereof, the twenty-sixth to twenty-ninth embodiments, and the thirty-third embodiment. The thirty-seventh embodiment of  FIG. 57  is configured such that cartilage conduction can be obtained by any site anywhere on the top of the mobile telephone  3301  being brought up against ear cartilage, but the thirty-eighth embodiment of  FIG. 58  expands on this feature; it is possible to listen to sound at an optimal volume merely by bringing the upper part of the mobile telephone  3401  up against the ear, at anywhere on the surface of the mobile telephone  3401 , regardless of the place. 
     In the thirty-eighth embodiment of  FIG. 58 , the cartilage conduction vibration source  2525  is anchored to the chassis structure  3426  such that the primary vibration direction of the piezoelectric bimorph element (the Y-Y′ direction) assumes an orientation orthogonal to that of a GUI display unit  3405  (conceptualized in the block diagram in  FIG. 58 , but is the large-screen display unit  205  having a touch panel function, when calling on the perspective view of  FIG. 41 , which relates to the twenty-sixth embodiment) (A cross-section of the anchoring is not illustrated in  FIG. 58 , but the manner of the anchoring will be described later). A large portion of the surface area of the front surface or the rear surface of the mobile telephone  3401 , to which the GUI display unit  3405  is provided, thereby vibrates efficiently. There is comparatively less energy in the non-vibration direction of the piezoelectric bimorph element (the X-X′ direction), due to the anchoring of the cartilage conduction vibration source  2525 , but because vibration does occur, sound can be listened to by cartilage conduction whenever a side surface of the mobile telephone  3401  is brought up against the ear cartilage. It shall be noted that the GUI display unit  3405  of  FIG. 58  is illustrated as a consolidation of the large-screen display unit  205  of  FIG. 42 , the display driver  41 , and the touch panel driver  2470 . 
     In the embodiment of  FIG. 58 , similarly with respect to the twenty-seventh embodiment, a function is selected by a motion sensor for the contactless detection of the motion of the finger in the vicinity of the GUI display unit  3405 , and an impact detection function of the piezoelectric bimorph element constituting the cartilage conduction vibration source  2525  is utilized as an impact sensor for detecting the touch of a finger for determining the selected function. The impact sensor  3442  illustrated in  FIG. 58  has a function similar to that of the pressure sensor  242  illustrated in  FIG. 9 , and extracts an impact detection signal of the piezoelectric bimorph element. The aforementioned arrangement of the primary vibration direction of the piezoelectric bimorph element (the Y-Y′ direction) to be oriented orthogonally with respect to that of the GUI display unit  3405  is suited for detecting a touch from the front surface or the back surface of the mobile telephone  3401 . The embodiment of  FIG. 58 , similarly with respect to the twenty-seventh embodiment, has the cartilage conduction vibration source  2525  serve a dual purpose as a low frequency output element for touch sensation feedback, but the aforementioned arrangement of the primary vibration direction of the piezoelectric bimorph element (the Y-Y′ direction) is suited for efficiently transmitting feedback vibration to a finger for a touch from the front surface or back surface of the mobile telephone  3401 . The embodiment of  FIG. 58 , similarly with respect to the description in the twenty-sixth embodiment, has the cartilage conduction vibration source  2525  serve a dual purpose as a vibration source of a vibrator for providing a noiseless notification of an incoming call to the mobile telephone  3401 . 
     The embodiment of  FIG. 58 , further similarly with respect to the fourth embodiment and similarly with respect to the twenty-seventh embodiment, is configured such that a horizontal stationary state is detected by the acceleration sensor  49 , and when this is true, the cartilage conduction vibration source  2525  is prohibited from vibrating. The potential generation of vibration noise with a desk due to the output of the other party&#39;s voice can thereby be prevented in a case in which the mobile telephone  3401  is placed on a desk or the like during a call. It is also appropriate to activate the aforementioned GUI operation or incoming call vibrator function in a case in which the mobile telephone  3401  is placed on a desk or the like, and thereof in such a case, the configuration is such that the cartilage conduction vibration source  2525  is not prohibited from vibrating whenever the horizontal stationary state is detected by the acceleration sensor  49 . A more detailed description of this point will be provided later as a function of the controller  3439 . 
     To configure the embodiment of  FIG. 58  such that the chassis structure  3426  of the mobile telephone  3401  is actively made to vibrate, there is the possibility that such vibration will be transmitted to the microphone  223  and result in the Larsen effect. As a countermeasure thereof, in order to block acoustic conduction between the chassis structure  3426  and microphone  223  of the mobile telephone  3401 , an insulation ring unit  3465  having an acoustic impedance different from that of the chassis structure  3426  is provided in between the two. A countermeasure for preventing the Larsen effect in a circuit-like manner is achieved using a signal conduction pathway from the outgoing-talk-processing unit  222  to the incoming-talk-processing unit  212  in the telephone function unit  45 . 
       FIG. 59  is a back surface transparent view and cross-sectional view illustrating the manner in which the cartilage conduction vibration source  2525  is anchored to the chassis structure  3426  of the mobile telephone  3401  in the thirty-eighth embodiment of  FIG. 58 .  FIG. 59A  is a back surface perspective view illustrating a part of the top end side of the mobile telephone  3401  of the thirty-eighth embodiment, and  FIG. 59B  is a cross-sectional view illustrating the B-B cross-section of  FIG. 59A .  FIG. 59C  is a transparent perspective view in which a part of the top end side in a modification example of the thirty-eighth embodiment is viewed from the side surface of the opposite side. The configuration of the piezoelectric bimorph element is similar to that in  FIG. 44B , and therefore portions that are in common have been given like reference numerals. 
     As is clear from  FIG. 59A , in the thirty-eighth embodiment, the metal sheet  2597  of the piezoelectric bimorph element constituting the cartilage conduction vibration source  2525  is arranged so as to be parallel to the front surface of the mobile telephone  3401 ; as a result thereof, the cartilage conduction vibration source  2525  is anchored to the chassis structure  3426  such that the Y-Y′ direction, which is the primary vibration direction, is oriented to be orthogonal to the GUI display unit  3405 . As is clear from  FIG. 59B , the piezoelectric bimorph element constituting the cartilage conduction vibration source  2525  is tightly secured on the inner side of the chassis structure  3426  without any gap, the configuration being such that the vibration in the primary vibration direction (the Y-Y′ direction) is prone to being transmitted to the surface of the chassis structure  3426 . 
     In a modification example of the thirty-eighth embodiment in  FIG. 59C , the metal sheet  2597  of the piezoelectric bimorph element constituting the cartilage conduction vibration source  2525  is arranged so as to be in parallel with the side surface of the mobile telephone  3401 ; as a result thereof, the cartilage conduction vibration source  2525  is anchored to the chassis structure  3426  such that the Y-Y′ direction, which is the primary vibration direction, is oriented to be orthogonal to the side surface of the mobile telephone  3401 . Cartilage conduction can thereby be efficiently obtained when the side surface of the mobile telephone  3401  is brought up against the ear. There is comparatively less energy in the non-vibration direction of the piezoelectric bimorph element (the X-X′ direction), due to the anchoring of the cartilage conduction vibration source  2525 , but because vibration does occur, sound can be listened to by cartilage conduction whenever the front surface or back surface of the mobile telephone  3401  is brought up against the ear cartilage. In the modification example of the thirty-eighth embodiment in  FIG. 59C  as well, similarly with respect to  FIG. 59B , the piezoelectric bimorph element constituting the cartilage conduction vibration source  2525  is tightly secured to the inner side of the chassis structure  3426 , without any gap, the configuration being such that the vibration in the primary vibration direction (the Y-Y′ direction) is likely to be transmitted to the surface of the chassis structure  3426 . 
       FIG. 60  is a flow chart of the operation of a controller  3439  in the thirty-eighth embodiment of  FIG. 58 . The flow of  FIG. 60  illustrates an abstraction of the operation that focuses on related functions, in order to primarily provide a description of the control of the cartilage conduction vibration source  2525 ; the controller  3439  also contains typical functions of mobile telephones and other operations not represented in the flow of  FIG. 60 . The flow of  FIG. 60  begins when a main power source of the mobile telephone  3401  is turned on; in step S 262  an initial startup and a check of each unit function are performed and a screen display on the GUI display unit  3405  is started. Subsequently, in step S 264 , the function of the cartilage conduction vibration source  2525  is turned off and the flow moves on to step S 266 . 
     In step S 266 , there is performed a check for whether or not the mobile telephone  3401  is in the middle of a call. When the line is newly connected, a call is in progress and therefore the flow proceeds to step S 268 , in which the outgoing-talk-processing unit  222  and the incoming-talk-processing unit  212  are turned on; the flow then moves on to step S 270 . In a case in which the line is connected and a call has already been in progress, the flow proceeds from step S 266  to step S 268 ; in such a case, the outgoing-talk-processing unit  222  and the incoming-talk-processing unit  212  are continuously kept on and the flow moves on to step S 270 . 
     In step S 270 , there is performed a check for whether or not a horizontal stationary state has been detected by the acceleration sensor  49 ; when there is no horizontal stationary state, the flow moves on to step S 272 , which turns on the cartilage conduction vibration source  2525 , whereupon the flow moves on to step S 274 . However, when the cartilage conduction vibration source  2525  is already on, the on state continues. On the other hand, when there is a detection of a horizontal stationary state in step S 270 , the flow proceeds to step S 276 , which checks for whether the outgoing-talk-processing unit  222  and the incoming-talk-processing unit  212  are in an on state. Then, in such a case, since an on state is in effect, the flow proceeds to step S 278 . The cartilage conduction vibration source  2525  is turned off and the flow moves on to step S 274 . When the cartilage conduction vibration source  2525  is already off, the off state continues. In step S 274 , there is performed a check for whether or not a call is in progress; when a call is in progress, the flow returns to step S 270 . Thereafter, as long as a call is in progress, steps S 270  to S 278  are repeated. In this manner, when the mobile telephone  3401  is temporarily placed on a desk or the like during a call, then whenever the voice of the other party is received, the vibration of the cartilage conduction vibration source  2525  is interrupted therebetween, and the generation of uncomfortable noise from vibration with the desk is prevented. As shall be apparent, when a horizontal stationary state is not detected in step S 270 , the cartilage conduction vibration source  2525  is turned on in step S 272  and the call is reactivated. 
     On the other hand, when it is detected in step S 266  that a state in which a call is not in progress is in effect or that a call is not in progress due to the termination of the call, the flow proceeds to step S 280 , the outgoing-talk-processing unit  222  and the incoming-talk-processing unit  212  are turned off, and the flow moves on to step S 282 . However, when the outgoing-talk-processing unit  222  and the incoming-talk-processing unit  212  are off, the off state continues and the flow moves on to step S 282 . In step S 282 , there is performed a check for whether there is an incoming call; when there is no incoming call, the flow moves on to step S 284 , in which there is performed a check for whether or not a GUI mode is in effect. Then, when a GUI mode is in effect, the flow proceeds to step S 286 , in which there is impact sensor detection processing; then, in step S 288 , there is touch sensation feedback processing, and the flow moves on to step S 290 . The flow moves directly on to step S 290  when there is no operation at all, and when there is an operation, Steps S 286  and S 288  perform processing for implementing impact sensor detection and touch sensation feedback, which are based on the operation. 
     In step S 290 , the low frequency source  2466  is turned on and prepared for the input of a touch sensation feedback signal or the like. The flow then proceeds to step S 270 , in which there is a check for the presence or absence of a detection of a horizontal stationary state. Then, when there is no horizontal stationary state, the flow moves on to step S 272 , in which the cartilage conduction vibration source  2525  is turned on and prepared for the input of a touch sensation feedback signal or the like. The flow moves on to step S 276  when a horizontal stationary state is detected in step S 270 , but in such a case, the outgoing-talk-processing unit  222  and the incoming-talk-processing unit  212  are not on, and therefore the flow still moves on to step S 272 , and the cartilage conduction vibration source  2525  is turned on. In this manner, the cartilage conduction vibration source  2525  is turned on when the low frequency source  2466  is turned on, even when a horizontal stationary state is detected. When the cartilage conduction vibration source  2525  is turned on, the impact sensor function thereof is also maintained. 
     On the other hand, when an incoming call is detected in step S 282 , the flow proceeds to step S 292 , a “vibe” signal for providing a notification of the incoming call is outputted; the flow then moves on to step S 290 . In such a case as well, the low frequency source  2466  is turned on in step S 290  and the cartilage conduction vibration source  2525  is turned on in step S 272 , but the flow also moves on to step S 272  even when the horizontal stationary state is detected in step S 270 , and the fact that the cartilage conduction unit  2525  is turned on is a point of similarity with the case in which the GUI mode is in effect. 
     When it is detected in step S 274  that no call is in progress, the flow moves on to step S 296 , in which there is performed a check for whether the primary power supply has been turned off. Once the low frequency source  2466  is turned on in step S 290 , no call is in progress even when step S 274  is reached, and therefore the flow moves on to step S 296 . When there is no detection made in step S 284  that a GUI mode is in effect, the flow proceeds to step S 294 , the low frequency source  2466  is turned off, and the flow then arrives at step  296 . When it is detected in step S 296  that the primary power supply has been turned off, the flow is terminated. On the other hand, in a case in which there is no detection made in step S 296  that the primary power supply is off, the flow returns to step S 266 , following which steps S 266  to S 296  are repeated and various situational changes are supported. 
     The various features of each of the embodiments described above are not to be limited to the above embodiments; rather, wherever it is possible to benefit from the feature of an embodiment, same can also be implemented in other aspects. The various features of each of the embodiments described above are not to be restricted to individual respective embodiments, but rather can be substituted or combined with other appropriate embodiments. For example, regarding the control of the cartilage conduction vibration source  2525  relating to being horizontally stationary, the thirty-eighth embodiment described above can be configured such that, in a case in which there is check for whether or not a videoconferencing function mode is in effect and the mode is in effect, the videoconferencing function speaker is turned on in tandem with the cartilage conduction vibration source  2525  being turned off in step S 278  of  FIG. 60 . 
     The mode in the thirty-eighth embodiment in which the cartilage conduction vibration source  2525  is supported by the chassis structure  3426  of the mobile telephone  3401  is not to be limited to a rigid, direct anchoring such as in the thirty-eighth embodiment. For example, the rigid support may be indirect, via another holding structure, provided that it remains possible to transmit vibration. The support is also not necessarily limited to being rigid; rather, holding may be achieved via an elastic body, provided that the acoustic impedance is approximated and vibration is transmitted to the chassis surface. 
     Thirty-Ninth Embodiment 
       FIG. 61  is a cross-sectional view relating to a thirty-ninth embodiment according to an aspect of the present invention as well as to various modification examples thereof, and is configured as mobile telephones  3501   a  to  3501   d . The thirty-ninth embodiment is consistent with, for example, the thirty-eighth embodiment illustrated in  FIGS. 58 to 60 , except for the arrangement of the cartilage conduction vibration source  2525 , which is constituted of a piezoelectric bimorph element (and which hereinafter is described using the example of the piezoelectric bimorph element  2525 ). Therefore, the diagram does not contain those portions for which no description is needed, and of the illustrated portions, shared portions have been given like reference numerals, a description thereof having been omitted unless there is a particular need. 
       FIG. 61A  relates to the thirty-ninth embodiment, and is a cross-sectional view in which the mobile telephone  3501   a  is viewed from above as being cut in a plane that is perpendicular to the side surface thereof and to the display surface of the GUI display unit  3405 . As is clear from the diagram, the piezoelectric bimorph element  2525  is arranged along one side surface of the mobile telephone  3501   a  as in the modification example of the thirty-eighth embodiment in  FIG. 59C . However, in the thirty-ninth embodiment of  FIG. 61 , the primary vibration direction of the piezoelectric bimorph element  2525  (the Y-Y′ direction) is not perpendicular to the side surface, but rather is supported so as to incline relative to the side surface. More specifically, the side surface of the thirty-ninth embodiment is provided with an inclined side surface  3507   a  to which four beveled side surface ridge portions are provided; the piezoelectric bimorph element  2525  has a primary vibration surface (the “outer surface of the piezoelectric bimorph element  2525  that is in parallel with the metal sheet  2597 ” is defined as the “primary vibration surface”) that is bonded to one inner side of the inclined side surface  3507   a  for support. The primary vibration direction (which is the Y-Y′ direction, and is the direction perpendicular to the primary vibration surface) of the piezoelectric bimorph element  2525  thereby becomes perpendicular to the inclined side surface  3507   a.    
     Due to such a structure, the user of the mobile telephone  3501   a  can prevent the display surface of the GUI display unit  3405  from being fouled by contact with the cheek, and can also readily bring the inclined side surface  3507   a  of the mobile telephone  3501   a  up against the ear cartilage. The configuration, which integrates the audio-related configuration into the side surface of the mobile telephone and integrates the visual-related configuration into the front surface of the mobile telephone, as has already been described in the other embodiments, is significant in that the uses of the two surfaces of the mobile telephone  3501   a  can be divided such that the side surface is utilized when the mobile telephone  3501   a  is brought up against the ear or other part of the face and the front surface is utilized when the mobile telephone is watched with the eyes, and in that the front surface of the mobile telephone  3501   a  can be prevented from having the display surface of the GUI display unit  3405  fouled by the face. However, rather than causing the side surface in its entirety to make perpendicular contact with the ear during the usage of the side surface, it is also possible to conceive of a usage state in which the mobile telephone  3501   a  is caused to make contact with the ear such that the display surface of the GUI display unit  3405  is turned slightly toward the face. The thirty-ninth embodiment of  FIG. 61A  is configured in anticipation of such usage. 
     As mentioned above, the thirty-ninth embodiment of  FIG. 61A  has the direction of arrow  25 A serving as the primary vibration direction in the inclined side surface  3507   a , in which the piezoelectric bimorph element  2525  is bonded to the inner side, but since the primary vibration direction is inclined, there is created a vibration component having a direction that is perpendicular to the display surface of the GUI display unit  3405 , illustrated by arrow  25 B. A side surface vibration component illustrated by arrow  25 C is also created. Sound can thereby be listened to even in a case in which the front surface of the mobile telephone  3501   a  (the display surface of the GUI display unit  3405 ) or the back surface thereof, and, furthermore, either of the two side surfaces of the mobile telephone  3501   a , is brought up against the ear cartilage. Any position of the mobile telephone  3501   a  can accordingly be discretionarily used, taking the direction of arrow  25 A as the best direction. In the thirty-ninth embodiment of  FIG. 61A , the inclined side surface  3507   a  assumes an incline that is close to the display surface of the GUI display unit  3405 ; therefore, the vibration component of the direction illustrated by arrow  25 B is greater than the vibration component of the direction illustrated by arrow  25 C. 
       FIG. 61B  is a first modification example of the thirty-ninth embodiment; the mobile telephone  3501   b  is configured such that the incline of the inclined side surface  3507   b  is substantially 45° relative to the display surface of the GUI display unit  3405 , whereby the vibration component of the direction illustrated by arrow  25 B becomes substantially even with the vibration component of the direction illustrated by arrow  25 C. By contrast,  FIG. 61C  is a second modification example of the thirty-ninth embodiment. The mobile telephone  3501   c  is configured such that the inclined side surface  3507   c  assumes an incline that is close to the side surface, whereby the vibration component of the direction illustrated by arrow  25 C becomes greater than the vibration component of the direction illustrated by arrow  25 B. 
       FIGS. 61A to 61C  are extreme illustrations for describing a broad overview of the inclines, but the extreme directivity in the vibration of the piezoelectric bimorph element  2525  is not maintained after having been transmitted to the mobile telephones  3501   a  to  3501   c ; therefore, subtle changes in the orientation of the primary vibration direction of the piezoelectric bimorph element  2525  provided to the side surface of the mobile telephone will not incur perceptible changes to the vibration components. However, there is great significance in adjusting the arrangement direction of the piezoelectric bimorph element  2525  as in the thirty-ninth embodiment and the modification examples thereof, when the best position of the contact with the ear cartilage is considered. For example, in a case as in  FIGS. 61A to 61C  in which a planar inclined side surface is provided, it is of practical utility for the front surface of the mobile telephones  3501   a  to  3501   c  (the display surface of the GUI display unit  3405 ) and the inclined side surfaces  3507   a  to  3507   c  to be imparted with an incline of between approximately 30 to 60°. 
       FIG. 61D  is a third modification example of the thirty-ninth embodiment; the side surface of a mobile telephone  3501   d  serves as a semicylindrical surface  3507   d . The configuration is such that support is provided by pushing on the inner side of the semicylindrical surface  3507   d  such that the primary vibration direction of arrow  25 A assumes a substantially 45° angle relative to the display surface of the GUI display unit  3405 , and the vibration component of the direction illustrated by arrow  25 B becomes substantially equivalent to the vibration component of the direction illustrated by arrow  25 C. The user is thereby able to bring up against the ear cartilage any desired place across the front surface of the mobile telephone  3501   d  (the display surface of the GUI display unit  3405 ) or across the back surface thereof, from the semicylindrical surface  3507   d  of the side surface. In the third modification example of the thirty-ninth embodiment of  FIG. 61D , the primary vibration direction of arrow  25 A is not limited to a case of having a substantially 45° angle relative to the display surface of the GUI display unit  3405 , and can be established in various inclines such as in  FIGS. 61A to 61C . Another possible configuration is one in which it is possible to adjust the incline of holding and in which a service for altering the incline in accordance with the user&#39;s desire can be provided. 
     Fortieth Embodiment 
       FIG. 62  represents cross-sectional views and a transparent perspective view of the elements relating to a fortieth embodiment according to an aspect of the present invention as well as to various modification examples thereof, and is configured as mobile telephones  3601   a  to  3601   c . The fortieth embodiment is also consistent with the thirty-eighth embodiment illustrated in  FIGS. 58 to 60 , except for the arrangement of the cartilage conduction vibration source  2525 , which is constituted of a piezoelectric bimorph element (and which hereinafter is described using the example of the piezoelectric bimorph element  2525 ). Therefore, the diagram does not contain those portions for which no description is needed, and of the illustrated portions, shared portions have been given like reference numerals, a description thereof having been omitted unless there is a particular need. 
       FIG. 62A  relates to the fortieth embodiment, and is a cross-sectional view in which the mobile telephone  3601   a  is viewed from above as being cut in a plane that is perpendicular to a side surface  3607  thereof and to the display surface of the GUI display unit  3405 . As is clear from the diagram, the piezoelectric bimorph element  2525  is arranged along one side surface  3607  of the mobile telephone  3601   a  as in the modification example of the thirty-eighth embodiment in  FIG. 59C . However, in the fortieth embodiment of  FIG. 62 , similarly with respect to the thirty-ninth embodiment, the piezoelectric bimorph element  2525  has a primary vibration direction (the Y-Y′ direction) that is not perpendicular to the side surface, the piezoelectric bimorph element  2525  being supported so as to be inclined relative to the side surface  3607 . The fortieth embodiment is configured such that the vibrations from the primary vibration surfaces of the two sides of the piezoelectric bimorph element  2525  are respectively transmitted to the mutually orthogonal side surface  3607  and display surface of the GUI display unit  3405 . 
     More specifically, the chassis of the mobile telephone  3601   a  of the fortieth embodiment in  FIG. 62A  is provided with a first support structure  3600   a  that extends to the inner side from the side surface  3607 , and is bonded to one primary vibration surface of the piezoelectric bimorph element  2525 ; and is also provided with a second support structure  3600   b  that extends to the inner side from the chassis on the display surface of the GUI display unit  3405 , and is bonded to the other primary vibration surface of the piezoelectric bimorph element  2525 . The primary vibration in the direction illustrated by arrow  25 A is thereby broken down into the vibration component illustrated by arrow  25 D and the vibration component illustrated by arrow  25 E having a direction orthogonal thereto, each of which being respectively transmitted to the side surface  3607  and the chassis surface on the display surface of the GUI display unit  3405 . In this manner, the vibration of the two primary vibration surfaces in the piezoelectric bimorph element  2525  is transmitted broken down into orthogonal directions of the mobile telephone  3601   a ; and the vibration of the piezoelectric bimorph element  2525  can be heard regardless of which portion of the front surface, the back surface, or the side surface of the mobile telephone  3601   a  is brought up against the ear cartilage. The fortieth embodiment in  FIG. 62A  is provided with the first support structure  3600   a  and the second support structure  3600   b  so as to sandwich the same portion of the piezoelectric bimorph element  2525  from two sides. 
     By contrast,  FIG. 62B  is a transparent perspective view in which the elements of the mobile telephone  3601   b  of a first modification example of the fortieth embodiment are viewed from within. As is clear from  FIG. 62B , in the first modification example of the fortieth embodiment, the first support structure  3600   a  and the second support structure  3600   b  are provided so as to be bonded to the mobile telephone  3601   b  in positions where the primary vibration surfaces facing the piezoelectric bimorph element  2525  mutually cross. The operation to bond to the piezoelectric bimorph element  2525  is thereby facilitated, the degree of freedom with which the piezoelectric bimorph element  2525  vibrates is less inhibited, and the vibration thereof can be efficiently transmitted to the chassis of the mobile telephone  3601   b.    
       FIG. 62C  is a cross-sectional view in which the mobile telephone  3601   c  of a second modification example of the fortieth embodiment is viewed from the side having been cut along a plane that is perpendicular to a side surface  3607   a  and the top surface. In the fortieth embodiment of  FIG. 62A , the primary vibration directions of the piezoelectric bimorph element  2525  are broken down into vibration components having directions perpendicular to the front surface and the side surfaces respectively, but in the second modification example of the fortieth embodiment in  FIG. 62C , the primary vibration directions of the piezoelectric bimorph element  2525  are broken down into vibration components having directions that are perpendicular to the front surface and the top surface respectively. 
     More specifically, as is clear from  FIG. 62C , the chassis of the mobile telephone  3601   c  in the second modification example of the fortieth embodiment is provided with a first support structure  3600   c  that extends to the inner side from the top surface, and is bonded to one primary vibration surface of the piezoelectric bimorph element  2525 . The chassis of the mobile telephone  3601   c  in the second modification example of the fortieth embodiment is also provided with a second support structure  3600   d  that extends to the inner side from the chassis on the display surface of the GUI display unit  3405 , and is bonded to the other primary vibration surface of the piezoelectric bimorph element  2525 . The primary vibration in the direction illustrated by arrow  25 A is thereby broken down into the vibration component illustrated by arrow  25 F and the vibration component illustrated by arrow  25 E having a direction orthogonal thereto, each being respectively transmitted to the top surface and the chassis surface on the display surface of the GUI display unit  3405 . In this manner, the vibration of the two primary vibration surfaces in the piezoelectric bimorph element  2525  is transmitted broken down into orthogonal directions of the mobile telephone  3601   c ; the vibration of the piezoelectric bimorph element  2525  can be heard regardless of which portion of the front surface, the back surface, the top surface, or the bottom surface of the mobile telephone  3601   c  is brought up against the ear cartilage. The second modification example of the fortieth embodiment in  FIG. 62C  has a cross-sectional view of a form in which the first support structure  3600   c  and the second support structure  3600   d  are provided such that the same portion of the piezoelectric bimorph element  2525  is sandwiched from both sides, similarly with respect to  FIG. 62A ; however, the configuration may be such that, as in  FIG. 62B , crossing portions of the two surfaces of the piezoelectric bimorph element  2525  are respectively bonded. 
     The second modification example of the fortieth embodiment in  FIG. 62C  is not only suited for listening to sound by bringing the front surface or the rear surface of the mobile telephone  3601   c  alongside the ear cartilage, but is also appropriate for usage in which the top surface of the mobile telephone  3601   c  is brought up against the ear cartilage in such a form as to lightly push upward. This embodiment is also appropriate in that by such usage, not only is the display surface prevented from being fouled by contact with the face, but increasing the force pushing upward on the top surface obstructs the external auditory meatus with the tragus, and the earplug bone conduction effect is readily created. 
     Forty-First Embodiment 
       FIG. 63  is a cross-sectional view relating to a forty-first embodiment according to an aspect of the present invention, and is configured as a mobile telephone  3701 . The forty-first embodiment is also consistent with the thirty-eighth embodiment illustrated in  FIGS. 58 to 60 , except for the arrangement of the cartilage conduction vibration source  2525 , which is constituted of a piezoelectric bimorph element (and which hereinafter is described using the example of the piezoelectric bimorph element  2525 ); therefore, the diagram does not contain those portions for which no description is needed, and of the illustrated portions, shared portions have been given like reference numerals, a description thereof having been omitted unless there is a particular need. 
       FIG. 63A  is a cross-sectional view in which the mobile telephone  3701  of the forty-first embodiment is viewed from above as being cut in a plane that is perpendicular to a side surface  3707  thereof and to the display surface of the GUI display unit  3405 . As is clear from the diagram, the piezoelectric bimorph element  2525  is arranged along the top surface of the mobile telephone  3701  as in the thirty-eighth embodiment in  FIG. 59A . The primary vibration direction of the piezoelectric bimorph element  2525  (the Y-Y′ direction) is a direction that is perpendicular to the display surface of the GUI display unit  3405 . Specifically, the middle portion of the piezoelectric bimorph element  2525  is bonded to a support structure  3700   a  that extends to the inner side from the back surface of the mobile telephone  3701 , and the two end portions of the piezoelectric bimorph element  2525  are supported together as free ends in a state in which vibration is not hampered. As a result, the counteraction of the free vibration of the two end portions of the piezoelectric bimorph element  2525  as illustrated by arrow  25 G and arrow  25 H is transmitted to the chassis of the mobile telephone  3701  via the support structure  3700   a  from the middle portion of the piezoelectric bimorph element  2525 . 
       FIG. 63B  is a cross-sectional view in which the B-B cross-section of  FIG. 63A  is viewed from the side of the mobile telephone  3701 ; it can be understood that the piezoelectric bimorph element  2525  is supported by the support structure  3700   a  in which the piezoelectric bimorph element  2525  extends to the inner side from the back surface of the mobile telephone  3701 , and also that the piezoelectric bimorph element  2525  is arranged along the top surface of the mobile telephone  3701 . As shown in  FIG. 63 , the structure, in which a part of the primary vibration surface of the piezoelectric bimorph element  2525  is supported on the inner side of the chassis of the mobile telephone  3701  and a part of the primary vibration surface is permitted to unrestrictedly vibrate in an unsupported manner, is appropriate for efficiently transmitting the vibration of the piezoelectric bimorph element  2525  to the chassis of the mobile telephone without adding any substantive change to the acoustic properties thereof. The support at the middle of the piezoelectric bimorph element  2525  such as in the forty-first embodiment is also particularly appropriate in a case of a piezoelectric bimorph element having a terminal positioned at the middle of the element, as in the thirty-second embodiment illustrated in  FIG. 51 . 
       FIG. 64  illustrates various modification examples of the forty-first embodiment of  FIG. 63 , and, similarly with respect to  FIG. 63A , is a cross-sectional view in which the mobile telephone  3701  is viewed from above as being cut in a plane that is perpendicular to the side surface  3707  thereof and to the display surface of the GUI display unit  3405 . 
       FIG. 64A  is a first modification example of the forty-first embodiment, and is particularly suited to a case in which the terminal  2525   b  of the piezoelectric bimorph element  2525  is positioned at an end part of the element, the center of gravity is unbalanced, and the free vibration of the terminal  2525   b  illustrated by arrow  25 G is slightly confined by the electrode connection to the element, compared to the vibration of the entire free end illustrated by arrow  25 H. To compensate for the unbalancing, the first modification example of  FIG. 64A  shifts the position of the support structure  3701   b  to the left in the diagram compared to the support structure  3700   a  of the forty-first embodiment of  FIG. 63 . 
       FIG. 64B  is a second modification example of the forty-first embodiment; each of the two ends of the piezoelectric bimorph element is bonded to a pair of support structures  3700   c  and  3700   d  that extend to the inner side from the back surface of the mobile telephone  3701 . The vibration of the middle portion of the piezoelectric bimorph element illustrated by arrow  25 I is thereby freed, and the counteraction of this vibration is transmitted to the chassis of the mobile telephone  3701  via the support structures  3700   c  and  3700   d.    
       FIG. 64C  is a third modification example of the forty-first embodiment, the terminal  2525   b  being bonded to a support structure  3700   e  extending inward from the back surface of the mobile telephone  3701 , whereby the piezoelectric bimorph element  2525  is supported on a cantilever structure. The counteraction of the vibration of the free ends of the piezoelectric bimorph element  2525  illustrated by arrow  25 H is thereby transmitted to the chassis of the mobile telephone  3701  via the support structure  3700   e.    
       FIG. 64D  is a fourth modification example of the forty-first embodiment; the piezoelectric bimorph element  2525  is bonded to the inner side of the chassis of the back surface of the mobile telephone  3701  interposed by a two-sided bonding sheet  3700   f  comprising an elastic body. The two-sided bonding sheet  3700   f  comprising an elastic body is made using an elastic body that has conductivity from the piezoelectric bimorph element  2525  to the chassis (a silicone rubber; a mixture of a silicone rubber and a butadiene rubber; a natural rubber; a structure formed using these varieties of rubber in which air bubbles are sealed; or the like) or the like. Due to such elastic bonding, each portion of the piezoelectric bimorph element  2525  obtains a degree of free vibration illustrated by arrows  25 G,  25 H, and  25 I, and the vibration thereof is transmitted to the chassis of the mobile telephone  3701  via the two-sided bonding sheet  3700   f.    
     The various features of each of the embodiments described above are not to be restricted to individual respective embodiments, but rather can be substituted or combined with other appropriate embodiments. For example, the support structure of the forty-first embodiment in  FIGS. 63 and 64 , in which consideration is given to the free vibration of the piezoelectric bimorph element  2525 , can also be applied to the case of the inclined holding of the piezoelectric bimorph element  2525  in the thirty-ninth embodiment of  FIG. 61  and the fortieth embodiment of  FIG. 62 . Specifically, the support structure in  FIG. 62B  has a point in common in the sense that the two ends of the piezoelectric bimorph element  2525  are supported and the middle part is freed. There is no limitation to this example; for example, rather than bonding the entire vibration plane to the inner side of the inclined side surface, it is also possible in the thirty-ninth embodiment of  FIG. 61  and the modification examples thereof to provide a projection unit analogous to the support structure  3700   a  of  FIG. 63A  to the inclined side surface, only the middle portion of the piezoelectric bimorph element  2525  being bonded thereto to make the two end parts thereof into free ends. Alternatively, it is also possible in the thirty-ninth embodiment of  FIG. 61  and the modification examples thereof to interpose an elastic body, as in the fourth modification example of the forty-first embodiment in  FIG. 64D , when the piezoelectric bimorph element  2525  is bonded. 
     The implementation of the features of the present invention described above is not to be limited to the aspects in the above embodiments; the invention can be implemented using other aspects as well, wherever it is possible to benefit from the advantages thereof. For example, although the thirty-ninth embodiment of  FIG. 61  has been described with the piezoelectric bimorph element  2525  being bonded to and supported by the inner side of the inclined side surface inside the mobile telephone, the specific structure for support is not to be limited thereto. For example, referring to the thirty-first embodiment of  FIG. 49 , the structure may be one in which a groove may be provided to the outer side of the inclined side surface and the piezoelectric bimorph element  2525  is fitted into this groove from the outer side. 
     Forty-Second Embodiment 
       FIG. 65  is a cross-sectional view relating to a forty-second embodiment according to an aspect of the present invention, and is configured as a mobile telephone  3801 . The forty-second embodiment is consistent with the thirty-eighth embodiment illustrated in  FIGS. 58 to 60 , except for the arrangement of the cartilage conduction vibration source  2525 , which is constituted of a piezoelectric bimorph element (and which hereinafter is described using the example of the piezoelectric bimorph element  2525 ), and except for the holding structure thereof therefore, the diagram does not contain those portions for which no description is needed, and of the illustrated portions, shared portions have been given like reference numerals, a description thereof having been omitted unless there is a particular need. 
       FIG. 65A  is a cross-sectional view in which the mobile telephone  3801  of the forty-second embodiment is viewed from above as being cut in a plane that is perpendicular to a side surface  3807  thereof and to the display surface of the GUI display unit  3405 .  FIG. 65B  is a cross-sectional view in which the B-B cross-section of  FIG. 65A  is viewed from the side of the mobile telephone  3801 . As is clear from  FIG. 65A , the piezoelectric element  2525  is arranged along the top surface of the mobile telephone  3801 , similarly with respect to the thirty-eighth embodiment in  FIG. 59A , the forty-first embodiment in  FIG. 63 , or the like. The primary vibration direction of the piezoelectric bimorph element  2525  is the direction perpendicular to the display surface of the GUI display unit  3405 , as illustrated by arrow  25 G. Thus, the forty-second embodiment of  FIG. 65 , in essence, has one side of the piezoelectric bimorph element  2525  supported by a cantilever structure, similarly with respect to the modification example of the forty-first embodiment illustrated in  FIG. 64C . The counteraction of the vibration of the free end of the piezoelectric bimorph element  2525  illustrated by arrow  25 G is thereby transmitted to the chassis of the mobile telephone  3801 . 
     A point of difference in the forty-second embodiment of  FIG. 65  from the modification example of the forty-first embodiment illustrated in  FIG. 64C  lies in it being configured such that an upper part corner  3824 , which is a site on the chassis of the mobile telephone  3801  that is appropriate for being brought up against the tragus or other ear cartilage, is made to vibrate particularly efficiently, and also such that it is possible for the structure of the upper part corner  3824 , which is also a site that is likely to bear the direct application of impact when a drop or the like occurs, to avoid having a structure that is low in terms of collision resistance. Specifically, as illustrated in  FIGS. 65A and 65B , one end of the piezoelectric bimorph element  2525  is inserted and held in a hole of a support structure  3800   a  extending inward from the side surface  3807  and the top surface  3807   a  of the mobile telephone  3801 , as a holding end  2525   c . The holding end  2525   c  is an end to which the terminal  2525   b  is not provided. Thus, making the one end to which the terminal  2525   b  is not provided into a holding end  2525   c  permits the support position to be brought closer to the vicinity of the upper part corner  3824 . By contrast, the other end to which the terminal  2525   b  is provided is made to vibrate as a free end. The terminal  2525   b  is connected to a circuit  3836  and flexible wiring  3836   a  installed in the chassis; the free vibration of the other end to which the terminal  2525   b  is provided will not be substantively hampered. The circuit  3836  comprises an amp or the like for boosting the drive voltage of the piezoelectric bimorph element  2525 . 
     Due to the configuration described above, the counteraction of the free vibration of the other end of the piezoelectric bimorph element  2525  illustrated by arrow  25 G is transmitted to the chassis of the mobile telephone  3801  via the support structure  3800   a  from the holding end  2525   c  of the piezoelectric bimorph element  2525 . At this time, the support structure  3800   a , as described above, is configured so as to extend to the inner side from the side surface  3807  and the top surface  3807   a  of the mobile telephone  3801  at the upper part corner  3824  of the chassis; therefore, the counteraction of the free vibration of the other end of the piezoelectric bimorph element  2525  is efficiently transmitted to the upper part corner  3824 . As described above, the piezoelectric bimorph element  2525  is held in the inner side of the chassis of the mobile telephone  3801 , and therefore the structure of the upper part corner  3824 , which is also a site that is prone to the direct application of an impact, will not have low resistance to collision. 
       FIG. 65C  is a first modification example of the forty-second embodiment; the piezoelectric bimorph element  2525  is held such that the primary vibration direction becomes the direction perpendicular to the top surface  3807   a , as illustrated by arrow  25 J. The structure is otherwise similar to that of the forty-second embodiment of  FIGS. 65A and 65B , and therefore a description thereof has been omitted. The first modification example in  FIG. 65C  has a large vibration component in the direction perpendicular to the top surface  3807   a , and is therefore suited for usage in which the top surface side of the upper part corner  3824  of the mobile telephone  3801  is brought up against the ear cartilage in such a form as to push lightly upward. This embodiment is also appropriate in that, due to such use, not only can the display surface of the GUI display unit  3405  be prevented from being fouled by contact with the face, but also increasing the force pushing upward on the top surface  3807   a  obstructs the external auditory meatus with the tragus, and the earplug bone conduction effect is readily created. The first modification example in  FIG. 65C , similarly with respect to the forty-second embodiment of  FIGS. 65A and 65B , can be used upon the display surface side of the upper part corner  3824  of the mobile telephone  3801  being brought up against the ear cartilage. In such a case as well, increasing the force with which the display surface is pushed against the ear cartilage makes it possible for the external auditory meatus to be obstructed with the tragus, and the earplug bone conduction effect can readily be created. 
       FIG. 65D  is a second modification example of the forty-second embodiment. The primary vibration direction is inclined 45° relative to the top surface  3807   a , as illustrated by arrow  25 K. The vibration components are thereby broken down into the direction that is perpendicular to the top surface  3807   a  and the direction that is perpendicular to the display surface of the GUI display unit  3405 , which is orthogonal thereto, and comparable cartilage conduction can be obtained regardless of the direction from which the upper part corner  3824  comes into contact with the ear cartilage. 
     Forty-Third Embodiment 
       FIG. 66  is a cross-sectional view relating to a forty-third embodiment according to an aspect of the present invention, and is configured as a mobile telephone  3901 . The forty-third embodiment is consistent with the thirty-eighth embodiment illustrated in  FIGS. 58 to 60 , except for the arrangement of the cartilage conduction vibration source  2525 , which is constituted of a piezoelectric bimorph element (and which hereinafter is described using the example of the piezoelectric bimorph element  2525 ), and except for the holding structure thereof. Therefore, the diagram does not contain those portions for which no description is needed, and of the illustrated portions, shared portions have been given like reference numerals, a description thereof having been omitted unless there is a particular need. 
       FIG. 66A  is a cross-sectional view in which the mobile telephone  3901  of the forty-third embodiment is viewed in profile as being cut in a plane that is perpendicular to the upper surface  3907   a  thereof and to the display surface of the GUI display unit  3405 .  FIG. 66B  is a cross-sectional view in which the B-B cross-section of  FIG. 66A  is viewed from above the mobile telephone  3901 . In the forty-third embodiment of  FIG. 66 , similarly with respect to the forty-second embodiment of  FIG. 65 , the one end in the piezoelectric bimorph element  2525  to which the terminal  2525   b  is not provided serves as a holding end  2525   c  and is supported by a cantilever structure. A point of difference in the forty-third embodiment from the forty-second embodiment lies in that, as is clear from  FIG. 66A , the piezoelectric bimorph element  2525  is arranged in parallel to the side surface of the mobile telephone  3901 , similarly with respect to the thirty-ninth embodiment in  FIG. 61  and the modification examples thereof. Further, the primary vibration direction of the piezoelectric bimorph element  2525  is the direction that is perpendicular to the display surface of the GUI display unit  3405 , as illustrated by arrow  25 M. 
     Accordingly, in the forty-third embodiment of  FIG. 66  as well, an upper part corner  3924 , which is a site on the chassis of the mobile telephone  3901  appropriate for being brought up against the tragus or other ear cartilage, vibrates particularly efficiently, and the structure of the upper part corner  3924  can avoid being low in terms of collision resistance. Specifically, similarly with respect to the forty-second embodiment, as illustrated in  FIGS. 66A and 66B , one end of the piezoelectric bimorph element  2525  is inserted into and held in a hole of the support structure  3900   a  extending inward from the side surface and the top surface of the mobile telephone  3901 , as a holding end  2525   c . Accordingly, the one end of the piezoelectric bimorph element  2525  to which the terminal  2525   b  is not provided is made into a holding terminal  2525   c  in the forty-third embodiment as well, whereby the support position can be brought closer to the vicinity of the upper part corner  3924 . This embodiment is otherwise consistent with the forty-second embodiment, and therefore a description has been omitted. 
       FIG. 66C  is a first modification example of the forty-third embodiment; the piezoelectric bimorph element  2525  is held such that the primary vibration direction becomes the direction perpendicular to the side surface  3907 , as illustrated by arrow  25 N. The configuration is otherwise similar to that of the forty-third embodiment in  FIGS. 66A and 66B , and therefore a description thereof has been omitted. The first modification example in  FIG. 66C  has a large vibration component in the direction perpendicular to the side surface  3907 , and is therefore suited for usage in which the side surface  3907  of the mobile telephone  3901  is brought up against the ear cartilage and contact between the face and the display surface of the GUI display unit  3405  is avoided. In the first modification example in  FIG. 66C , similarly with respect to the forty-third embodiment in  FIGS. 66A and 66B , the display surface side of the mobile telephone  3901  can be brought up against the ear cartilage for use. In such a case as well, in a case in which the upper part corner  3924  is pushed against the ear cartilage, increasing the force thereof makes it possible to obstruct the external auditory meatus with the tragus, and to readily create the earplug bone conduction effect. 
       FIG. 66D  is a second modification example of the forty-third embodiment. The primary vibration direction is inclined 45° relative to the side surface  3907 , as illustrated by arrow  25 P. The vibration components are thereby broken down into the direction that is perpendicular to the side surface  3907  and to the direction that is perpendicular to the display surface of the GUI display unit  3405 , which is orthogonal thereto, and comparable cartilage conduction can be obtained regardless of the direction from which the upper part corner  3924  comes into contact with the ear cartilage. 
     Forty-Fourth Embodiment 
       FIG. 67  is a cross-sectional view relating to a forty-fourth embodiment according to an aspect of the present invention, and is configured as a mobile telephone  4001 . The forty-fourth embodiment is consistent with the thirty-eighth embodiment illustrated in  FIGS. 58 to 60 , except for the structure and arrangement of the cartilage conduction vibration source  2525 , which is constituted of a piezoelectric bimorph element, and except for the holding structure thereof. Therefore, the diagram does not contain those portions for which no description is needed, and of the illustrated portions, shared portions have been given like reference numerals, a description thereof having been omitted unless there is a particular need. 
       FIG. 67A  is a cross-sectional view (which includes a partial conceptual block diagram) in which the mobile telephone  4001  of the forty-fourth embodiment is viewed from above as being cut in a plane that is perpendicular to the side surface thereof and to the display surface of the GUI display unit  3405 , and is a cross-sectional view that can be understood to be similar with respect to the forty-second embodiment of  FIG. 65A . FIGS.  67 B 1  and  67 B 2  are cross-sectional views in which the B 1 -B 1  cross-section and B 2 -B 2  cross-section of the elements in  FIG. 67A  are viewed from the side of the mobile telephone  4001 , respectively.  FIG. 67C  is a detailed cross-sectional view of the important elements of  FIG. 67A  (including a partial conceptual block diagram). Portions in FIGS.  67 B 1 ,  67 B 2 , and  67 C that correspond to  FIG. 67A  have been given like reference numerals, and a description thereof has been omitted unless there is a particular need. 
     The forty-fourth embodiment of  FIG. 67 , similarly with respect to the forty-second embodiment of  FIG. 65 , has the piezoelectric bimorph element  2525  supported in parallel with the top surface, but differs from the forty-second embodiment in that the one end side to which the terminal  2525   b  is provided is supported by the cantilever structure, and in that a circuit  4036  for driving the piezoelectric bimorph element  2525  is integrated with the piezoelectric bimorph element  2525  for a configuration as a vibration unit. This embodiment is consistent with the forty-second embodiment in that the upper part corner, which is an appropriate site on the chassis of the mobile telephone  4001  to be brought up against the tragus or other ear cartilage, vibrates particularly efficiently, and also in that the upper part corner avoids having a structure that is low in terms of collision resistance. 
     Specifically, as illustrated in  FIGS. 67A and 67C , the terminal  2525   b  of the piezoelectric bimorph element  2525  is connected to a circuit  4036  that is mounted onto the terminal  2525   b  using a wire  4036   a . The terminal  2525   b  of the piezoelectric bimorph element  2525  and the circuit  4036  are re-packaged using a resin package  4025  having an acoustic impedance approximating that of the resin in which the piezoelectric bimorph element  2525  has been packaged, and are integrated as a vibration unit. A connection pin  4036   b  penetrates the resin package  4025 , projects outward from the circuit  4036 , and makes contact with a controller and power supply unit  4039  secured to the chassis of the mobile telephone  4001 . 
     As illustrated in  FIG. 67C , the circuit  4036  comprises an amp  4036   c  for boosting the drive voltage of the piezoelectric bimorph element  2525 , and an adjustment unit  4036   d  for electrically compensating for the variances of the piezoelectric bimorph element  2525 . The adjustment unit  4036   d  performs adjustments so as to operate to prevent variances in the piezoelectric bimorph element  2525  relative to the power feed and control from the controller and power supply unit  4039 ; therefore, after adjustments are done, repackaging is done with the resin  4024 . As an alternative configuration, it is possible for repackaging to be performed so that an adjustment operation unit or adjustment circuit pattern of the adjustment unit  4036   d  is exposed on the surface of the resin package  4025 , and so that adjustments can be performed after assembly. 
     In the forty-fourth embodiment of  FIG. 67 , similarly with respect to the forty-second embodiment, a support structure  4000   a  extending inward from the side surface and top surface  4007   a  of the mobile telephone  4001  is provided, a portion of the resin package  4025  of the vibration unit formed by repackaging being inserted into a hole thereof, whereby the piezoelectric bimorph element  2525  is held. As has already been described, in the forty-fourth embodiment, one end side to which the terminal  2525   b  is provided is supported, and one end  2525   c  to which the terminal  2525   b  is not provided serves as a unrestrictedly vibrating end. The counteraction of the free vibration of the one end  2525   c  is then transmitted to the chassis of the mobile telephone  4001  via the support structure  4000   a  from the resin package  4025 . 
     The various features indicated in the embodiments of the present invention can be unrestrictedly substituted or combined whenever the benefits thereof can be utilized. For example, in the forty-fourth embodiment of  FIG. 67 , the piezoelectric bimorph element  2525  is supported in parallel with the top surface, and the primary vibration direction thereof becomes the direction perpendicular to the display surface of the GUI display unit  3405 , as illustrated by arrow  25 H. However, the integrated packaging structure of the piezoelectric bimorph element  2525  and the circuit  4036  illustrated in the forty-fourth embodiment is not to be limited to the arrangement of  FIG. 67 , but rather can be utilized in a support arrangement such as in the modification example of the forty-second embodiment illustrated in  FIGS. 65C and 65D , and in the forty-third embodiment illustrated in  FIGS. 66A to 66D  and the modification example thereof. The utilization thereof may be done in conformity with the relationships between  FIGS. 65A and 67A , and in each case, the one end of the side of the piezoelectric bimorph element  2525  to which the terminal  2525   b  is provided serves as the support side, similarly with respect to  FIG. 65A . 
     The support structures  3800   a ,  3900   a , and  4000   a  in the forty-second embodiment of  FIG. 65  to the forty-fourth embodiment in  FIG. 67  are also not limited as extending inward from the side surface and top surface of the mobile telephone  4001 ; rather, a variety of support structures are possible. For example, a support structure may be configured so as to extend from only one of either the side surface or the top surface. Moreover, a variety of other structures are possible, including one extending from either the front surface or the back surface, one extending from the front surface and the top surface; one extending from the rear surface and the top surface; one extending from the side surface and the front surface; one extending from the side surface and the rear surface; or one extending from the rear side of the corner part as an elongation from all three of the top surface, the side surface, and the front surface. In each case, providing the piezoelectric bimorph element  2525  or the support unit of the resin packaging  4025  integrated therewith to the inner side of the chassis in the vicinity of the corner part can allow the corner part to avoid having a structure that is low in terms of collision resistance while also causing the corner part to vibrate efficiently due to the counteraction of the free vibration of the other end. 
     The various features indicated in each of the embodiments of the present invention are also not necessarily specific to individual embodiments; rather, the features of each respective embodiment can be modified and used or combined and used as appropriate, whenever it is possible to utilize the benefits thereof. For example, in the first embodiment of  FIG. 1 , the second embodiment of  FIG. 5 , the third embodiment of  FIG. 6 , and the thirty-fifth embodiment of  FIG. 55 , the interior of the mobile telephone is provided with two piezoelectric bimorph elements respectively for right ear use and left ear use. However, examples in which each of a plurality of piezoelectric bimorph elements is provided to a plurality of places in the mobile telephone in order to obtain desired cartilage conduction from a plurality of directions are not to be limited to these embodiments. On the other hand, in the thirty-ninth embodiment of  FIG. 61 , the fortieth embodiment of  FIG. 62 , the second modification example of the forty-second embodiment in  FIG. 65D , and the second modification example of the forty-third embodiment in  FIG. 66D , a single primary vibration direction of the piezoelectric bimorph element is given an incline and the vibration component is divided in a case in which cartilage conduction is to be generated in a plurality of directions, such as between the side surface and the front surface or between the top surface and the front surface; however, configurations for generating cartilage conduction in a plurality of directions are not to be limited to these embodiments. 
     Forty-Fifth Embodiment 
       FIG. 68  is a cross-sectional view relating to the forty-fifth embodiment according to an aspect of the present invention, and serves to illustrate another example relating to the configuration described above in which cartilage conduction is generated in a plurality of directions, such as between the side surface and front surface, and between the top surface and the front surface. Specifically, in a mobile telephone  4101   a  of the forty-fifth embodiment illustrated in  FIG. 68A  and a mobile telephone  4101   b  of a modification example thereof illustrated in  FIG. 68B , two piezoelectric bimorph elements are utilized in imitation of the thirty-fifth embodiment of  FIG. 55  and the like, instead of the dividing of the vibration component of a single piezoelectric bimorph elements such as in the fortieth embodiment of  FIG. 62 . Then, the primary vibration directions of these piezoelectric bimorph elements  4124  and  4126  are set off from each other by 90° so as to become parallel to the front surface and side surface or to the front surface and top surface, respectively, the bimorph elements being supported on the inner side of the chassis of the mobile telephone. Similarly with respect to the fortieth embodiment of  FIG. 62 , cartilage conduction is thereby generated in a plurality of directions, such as between the side surface and front surface or between the top surface and front surface. The configuration of the forty-fifth embodiment of  FIG. 68  is shared with that of the fortieth embodiment of  FIG. 62 , other than the fact that two piezoelectric bimorph elements are utilized; therefore, identical portions have been given like reference numerals, and extraneous description has been omitted. It shall be noted that  FIGS. 68A and 68B  correspond to  FIGS. 62A and 62C , respectively. 
     In  FIG. 68 , the longitudinal directions of the two piezoelectric bimorph elements illustrate a parallel arrangement, but the arrangement of the plurality of piezoelectric bimorph elements is not limited thereto. For example, another possible arrangement is one in which the longitudinal directions of the two piezoelectric bimorph elements are mutually orthogonal, where one is along the top surface and the other is along the side surface. Furthermore, the support of the plurality of piezoelectric bimorph elements in which the primary vibration directions are set off from each other is not limited to the inner side of the chassis of the mobile telephone as in  FIG. 68 ; rather, for example, the support may be on the outer side of the chassis, as in the thirtieth and thirty-first embodiments and the modification examples thereof illustrated in  FIGS. 48 to 50 . 
     Forty-Sixth Embodiment 
       FIG. 69  is a perspective view and a cross-sectional view relating to a forty-sixth embodiment according to an aspect of the present invention, and is configured as a mobile telephone  4201 . The forty-sixth embodiment is consistent with the thirty-eighth embodiment illustrated in  FIGS. 58 to 60 , except for the arrangement of the cartilage conduction vibration source  2525 , which is constituted of a piezoelectric bimorph element, and except for the holding structure thereof; therefore, the diagram does not contain those portions for which no description is needed, and of the illustrated portions, shared portions have been given like reference numerals, a description thereof having been omitted unless there is a particular need. 
       FIG. 69A  is a perspective view in which the mobile telephone  4201  of the forty-fourth embodiment is viewed from the front surface; the four corner parts, which are susceptible to collision when the mobile telephone  4201  is dropped by mistake or in other circumstances, are provided with elastic body units  4263   a ,  4263   b ,  4263   c ,  4263   d , which serve as protectors. The inner sides of the elastic body units  4263   a  and  4263   b  found at the two upper corner parts have a dual purpose as units for holding the piezoelectric bimorph element, and the outer sides of the elastic body units  4263   a  and  4263   b  have a dual purpose as cartilage conduction units for making contact with the ear cartilage. For this reason, at least the elastic body units  4263   a  and  4263   b  utilize an elastic material having an acoustic impedance approximating that of ear cartilage (a silicone rubber; a mixture of a silicone rubber and a butadiene rubber; a natural rubber; a structure formed using these varieties of rubber in which air bubbles are sealed; a structure, such as can be seen in transparent packaging sheet materials and the like, in which a layer of groups of air bubbles is sealed separated by a thin film of synthetic resin; or the like). 
       FIG. 69B  is a cross-sectional view in the B 1 -B 1  sectional plane of  FIG. 69A , with a cross-section of the mobile telephone  4201  in the plane perpendicular to the front surface and the side surface. As is clear from  FIG. 69B , the two ends of the piezoelectric bimorph element  2525  are supported by the inner sides of the elastic body units  4263   a  and  4263   b . The elastic body unit  4263   a  supports the terminal  2525   b  side of the piezoelectric bimorph element  2525 , and a flexible wiring  3836   a  for establishing a connection between the terminal  2525   b  and the circuit  3836  passes through the elastic body unit. 
     The elastic body units  4263   a  and  4263   b  are anchoringly supported on the chassis of the mobile telephone  4201 , but the two ends of the piezoelectric bimorph element  2525  are ensured a certain degree of freedom to move by vibration, due to the elasticity of the elastic body units  4263   a  and  4263   b , and the vibration of the piezoelectric bimorph element  2525  is less hampered. The middle part of the piezoelectric bimorph element  2525  is not in contact with anything and is free to vibrate. The outer sides of the elastic body units  4263   a  and  4263   b , serve as an outer wall of the corner parts of the mobile telephone  4201 , and have a dual purpose in acting as protectors for collisions with an external unit, and as cartilage conduction units for making contact with the ear cartilage. The mobile telephone  4201  can thereby be brought into contact with either of the right ear or the left ear for the purpose of cartilage conduction, as has been described in, for example, the first embodiment in  FIGS. 2A and 2B . Furthermore, because the elastic body units  4263   a  and  4263   b  have a different acoustic impedance from that of the chassis of the mobile telephone  4201 , the conduction component from the elastic body units  4263   a  and  4263   b  to the chassis of the mobile telephone  4201  can be reduced, and efficient cartilage conduction from the elastic body unit  4263   a  or  4263   b  to the ear cartilage can be achieved. 
       FIG. 69C  is a cross-sectional view in the B 2 -B 2  sectional plane illustrated in  FIG. 69A  or  FIG. 69B , with a cross-section of the mobile telephone  4201  in the plane perpendicular to the front surface and the top surface. It can be understood from  FIG. 69C  as well that the elastic body units  4263   a  and  4263   b  hold the piezoelectric bimorph element  2525  and are anchoringly supported on the chassis of the mobile telephone  4201 , and also that the outer sides thereof, without the outer wall of the corner parts of the mobile telephone  4201 , serve as protectors for collisions with an external unit, and have a dual purpose as cartilage conduction units for making contact with the ear cartilage. As is clear from  FIG. 69C , the forty-sixth embodiment assumes a structure in which the elastic body units  4263   c  and  4263   d , which are at the lower two corners, function exclusively as protectors, and are covered by the chassis of the mobile telephone  4201 . 
     Forty-Seventh Embodiment 
       FIG. 70  relates to the forty-seventh embodiment according to an aspect of the present invention;  FIG. 70A  is a perspective view illustrating a part of the upper end side thereof, and  FIG. 70B  is a cross-sectional view illustrating the B-B cross-section of  FIG. 70A . The seventieth embodiment is configured as a mobile telephone  4301 , and assumes a structure in which the piezoelectric bimorph element  2525  is fitted into the side surface of the mobile telephone. Such a structure has much in common with the thirtieth embodiment illustrated in  FIG. 48 , and therefore common portions have been given like reference numerals, and a description thereof has been omitted. Further, similarly with respect to  FIG. 48 ,  FIG. 70  omits an illustration and description of the configuration for inputting an audio signal into the cartilage conduction vibration source  2525 , and the like. 
     A point of difference in the forty-seventh embodiment of  FIG. 70  from the thirtieth embodiment of  FIG. 49  lies in the structure of the portions for transmitting the vibration of the piezoelectric bimorph element  2525  to the ear cartilage. Namely, in the forty-seventh embodiment of  FIG. 70 , the side surface of the mobile telephone  4301  is provided with a concavity  4301   a  that has a very slight step (for example, 0.5 mm), and is arranged such that the vibration plane of the piezoelectric element  2525  comes to a bottom part of this concavity  4301   a . The vibration plane of the piezoelectric bimorph element  2525  may be exposed at the bottom part of the concavity  4301   a , but in the forty-seventh embodiment, the piezoelectric bimorph element  2525  is covered with a thin protective layer  4227 . This protective layer  4227  is applied or coated on with an elastic material, in order to prevent stretching of the vibration plane due to vibration of the piezoelectric bimorph element  2525  from being hampered. 
     Due to the structure described above, it is possible to bring the vibration plane of the piezoelectric bimorph element  2525  into direct contact with the ear cartilage wherever possible, and also it is possible to provide protection against damage to the piezoelectric bimorph element  2525  from any collision with an external unit. Specifically, the piezoelectric bimorph element  2525  is arranged at the bottom of the concavity  4301   a  and is at a position that is lower only by the step from the outer surface of the chassis of the mobile telephone  4301 ; because of the step, the piezoelectric bimorph element  2525  will not directly collide with an external unit even were the side surface of the chassis of the mobile telephone to collide with an external unit. As illustrated in  FIG. 70A , in the forty-seventh embodiment, the concavity  4301   a  is provided to a place slightly lowered from the corner part in the side surface of the mobile telephone  4301 , to prevent any damage to the piezoelectric bimorph element  2525  due to collision at the corner part. Ear cartilage is soft; therefore, it is readily deformed at the place of the very slight step and can be brought into contact with the vibration plane of the piezoelectric bimorph element  2525  or the covered surface thereof, even with an arrangement such that the vibration plane of the piezoelectric bimorph element  2525  comes to the bottom part of the concavity  4301   a.    
     The various features indicated in the various embodiments of the present invention can be unrestrictedly modified, substituted or combined whenever the benefits thereof can be utilized. For example, the elastic body units  4263   a  and  4263   b  are arranged in the forty-sixth embodiment of  FIG. 69  so as to be symmetrical relative to the center of the piezoelectric bimorph element  2525 , but the support of the piezoelectric bimorph element  2525  is not to be limited to such an arrangement; another possible arrangement is an eccentric one in which the center of the piezoelectric bimorph element  2525  is closer to either of the opposing corner parts. For example, the piezoelectric bimorph element  2525 , rather than being completely symmetrical relative to the center thereof, has a slightly different weight and degree of freedom to vibrate at the side that is not the side that has the terminal  2525   b . The wiring  3836   a  also passes through the elastic body unit  4263   a  for supporting the terminal  2525   b , and passes through to the circuit  3836 . The configuration for eccentrically supporting the piezoelectric bimorph element  2525  between the two corner parts is effective in compensation for asymmetry such as described above. The respective lengths of the elastic body units  4263   a  and  4263   b  must be determined depending on the length of the piezoelectric bimorph element  2525  and on the width of the chassis of the mobile telephone  4201 . In other words, the elastic body units  4263   a  and  4263   b  require enough length to reach up to the two ends of the piezoelectric bimorph element  2525  from the outer surface of the two corner parts of the chassis of the mobile telephone  4201 . The configuration for eccentrically supporting the piezoelectric bimorph element  2525  between the two corner parts is effective in that the length can be adjusted as above while keeping the layout of the implemented parts inside the mobile telephone in consideration. In a case in which the elastic body unit  4263   a  or  4263   b  becomes longer, the configuration is such that the elastic body unit  4263   a  or  4263   b  is elongated inward so as not to make contact with the inner surface of the chassis, and reaches the end part of the piezoelectric bimorph element  2525 , whereby it is also possible to increase the degree of freedom with which the end part of the piezoelectric bimorph element  2525  vibrates. 
       FIG. 71  is a perspective view and a cross-sectional view relating to a modification example of the forty-sixth embodiment according to an aspect of the present invention, and serves to illustrate the implementation of a configuration in a case in which the elastic body unit is longer, as described above. Specifically, a case in which, as illustrated in  FIG. 71 , the elastic body units  4263   a  and  4263   b  become longer utilizes a configuration in which there are provided elongation units  4263   e  and  4263   f , by which the elastic body units  4263   a  and  4263   b  are elongated inward so as not to make contact with the inner surface of the chassis of the mobile telephone  4201 , the two end parts of the piezoelectric bimorph element  2525  being held by these elongation units  4263   e  and  4263   f  According to such a configuration, the elongation units  4263   e  and  4263   f  do not make contact with the inner surface of the chassis of the mobile telephone  4201 , and therefore elastic deformation is readily possible, and the two end parts of the piezoelectric bimorph element  2525  can be held by such elongation units  4263   e  and  4263   f , whereby the degree of freedom with which the piezoelectric bimorph element  2525  vibrates can be increased. The configuration of  FIG. 71  is otherwise consistent with that of  FIG. 69 , and therefore shared portions have been given like reference numerals, and a description thereof has been omitted. 
     The various features indicated in the various embodiments of the present invention can be unrestrictedly modified, substituted, or combined whenever the benefits thereof can be utilized. For example, each of the embodiments above has been described with the cartilage conduction vibration source comprising a piezoelectric bimorph element or the like. However, barring particular cases described as pertaining to a configuration specific to the piezoelectric bimorph element, the various features of the present invention are not to be limited to cases in which a piezoelectric bimorph element is utilized as the cartilage conduction vibration source; the advantages thereof can also be realized in a case in which an electromagnetic vibrating element, a super magnetostrictive element, or other diverse elements are used for the cartilage conduction vibration source. 
     Forty-Eighth Embodiment 
       FIG. 72  is a perspective view and a cross-sectional view relating to a forty-eighth embodiment according to an aspect of the present invention, and is configured as a mobile telephone  4301 . The forty-eighth embodiment serves as an example of a case in which an electromagnetic vibrating element is used as the cartilage conduction vibration source in the configuration of the forty-sixth embodiment in  FIG. 69 .  FIG. 72A  is a perspective view in which the mobile telephone  4301  of the forty-eighth embodiment is viewed from the front surface thereof; the outer appearance is similar to that of the perspective view of the forty-sixth embodiment in  FIG. 69A . In other words, in the forty-eighth embodiment as well the four corner parts, which are susceptible to collision when the mobile telephone  4301  is dropped by mistake or in other circumstances, are provided with elastic body units  4363   a ,  4363   b ,  4363   c , and  4363   d , which serve as protectors. The elastic body units  4363   a  and  4363   b , which are at the upper two corners, have a dual purpose as units for holding the cartilage conduction vibration source, and the outer sides of the elastic body units  4363   a  and  4363   b  have a dual purpose as cartilage conduction units for making contact with the ear cartilage. Then, the elastic body units  4363   a  and  4363   b , similarly with respect to the forty-sixth embodiment, utilize an elastic material having an acoustic impedance approximating that of ear cartilage (a silicone rubber; a mixture of a silicone rubber and a butadiene rubber; a natural rubber; a structure formed using these varieties of rubber in which air bubbles are sealed; a structure, such as can be seen in transparent packaging sheet materials and the like, in which a layer of groups of air bubbles is sealed separated by a thin film of synthetic resin; or the like). 
       FIG. 72B  is a cross-sectional view in the B-B sectional plane of  FIG. 72A , wherein the mobile telephone  4301  (represented as  4301   a  in  FIG. 72B ) is sectioned along the plane perpendicular to the front surface and the side surface. As is clear from  FIG. 72B , each of electromagnetic vibrating elements  4326   a  and  4324   a  is embedded in the elastic body units  4363   a  and  4363   b , respectively. The primary vibration direction thereof is the direction perpendicular to the front surface of the mobile telephone  4301  to which a GUI display unit is provided, as illustrated by arrow  25 M. In the configuration in which the electromagnetic vibrating elements  4326   a  and  4324   a  or other cartilage conduction vibration sources are embedded in the elastic body units  4363   a  and  4363   b , the elastic body units  4363   a  and  4363   b  have a dual purpose as a protector function and a cartilage conduction unit function, as described above, and also, as described in the embodiment of  FIG. 17 , additionally have yet another purpose as a cushioning function for guarding the cartilage conduction vibration source against impact. 
     In the configuration in which, as in the forty-eighth embodiment in  FIG. 72B , the separate electromagnetic vibrating elements  4326   a  and  4324   a  are provided to the elastic body unit  4363   a  and  4363  respectively, the electromagnetic vibrating elements  4326   a  and  4324   a  can be controlled independently. Accordingly, similarly with respect to the first embodiment illustrated in  FIGS. 1 to 4 , the configuration can be made to be such that the inclined direction of the mobile telephone  4301  is detected according to the gravity acceleration detected by the acceleration sensor, and, in accordance with which of the elastic body units  4363   a  and  4363   b  is brought up against the ear (in other words, in accordance with against which among the right ear and left ear the corner part of the mobile telephone has been brought, as illustrated in  FIG. 2 ), the electromagnetic vibrating element on the side at the lower angle of inclination is made to vibrate, and the other is turned off. This is also similar to a modification example that will be described later. 
       FIG. 72C  is a cross-sectional view of the first modification example of the forty-eighth embodiment, and, similarly with respect to  FIG. 72B , is a cross-sectional view in the B-B sectional plane of  FIG. 72A , wherein the mobile telephone  4301  (represented as  4301   b  in  FIG. 72C ) is sectioned along the plane perpendicular to the front surface and the side surface. Similarly with respect to the forty-eighth embodiment, the first modification example also has the electromagnetic vibrating elements  4326   b  and  4324   b  embedded in the elastic body units  4363   a  and  4363   b , respectively. However, the primary vibration direction thereof becomes the direction perpendicular to the side surface of the mobile telephone  4301 , as illustrated by arrow  25 N. This modification example is otherwise similar to the forty-eighth embodiment of  FIG. 72B . 
       FIG. 72D  is a cross-sectional view of the second modification example of the forty-eighth embodiment, and, similarly with respect to  FIG. 72B , is a cross-sectional view in the B-B sectional plane of  FIG. 72A , wherein the mobile telephone  4301  (represented as  4301   c  in  FIG. 72D ) is sectioned along the plane perpendicular to the rear surface and the side surface. In the second modification example, similarly with respect to the forty-eighth embodiment, each of the electromagnetic vibrating elements  4326   c  and  4324   c  is embedded in the elastic body units  4363   a  and  4363   b , respectively. However, the primary vibration direction thereof becomes a direction inclined 45° from the side surface of the mobile telephone  4301 , as illustrated by arrow  25 P. For this reason, similarly with respect to the second modification example of the forty-third embodiment in  FIG. 66D , the vibration components are broken down into the direction that is perpendicular to the side surface and to the direction that is perpendicular to the front surface, which is orthogonal thereto, and comparable cartilage conduction can be obtained regardless of the direction from which the either the elastic body unit  4363   a  or  4363   b  comes into contact with the ear cartilage. This modification example is otherwise similar to the forty-eighth embodiment of  FIG. 72B . 
       FIG. 72E  is a cross-sectional view of the third modification example of the forty-eighth embodiment, and, similarly with respect to  FIG. 72B , is a cross-sectional view in the B-B sectional plane of  FIG. 72A , wherein the mobile telephone  4301  (represented as  4301   d  in  FIG. 72E ) is sectioned along the plane perpendicular to the front surface and the side surface. In the third modification example, electromagnetic vibrating elements  4326   d ,  4326   e , and  4324   d ,  4324   e  are embedded in the elastic body units  4363   a ,  4363   b , respectively. The vibration direction of the electromagnetic vibrating elements  4326   d  and  4324   d  is the direction perpendicular to the side surface, illustrated by arrow  25 D, and that of the electromagnetic vibrating elements  4326   e  and  4324   e  becomes the direction perpendicular to the front surface, illustrated by arrow  25 E. Similarly with respect to the forty-fifth embodiment illustrated in  FIG. 68 , earplug bone conduction is thereby generated to the side surface and the front surface from a plurality of different cartilage conduction vibration sources. 
     In the configuration in which, as in the third modification example of the forty-eighth embodiment in  FIG. 72E , vibration that is directed perpendicularly with respect to the side surface is generated from the electromagnetic vibrating element  4324   d  and the like and vibration that is directed perpendicularly with respect to the front surface is generated from the electromagnetic vibrating element  4324   e  and the like, it is possible to independently control the electromagnetic vibrating elements  4324   d  and  4324   e  having different vibration directions. Specifically, a possible configuration is one in which the incline direction of the mobile telephone  4301  is detected by gravity acceleration, which is detected by an acceleration sensor such as the acceleration sensor  49  of the first embodiment illustrated in  FIG. 3 , where, in accordance with whether the elastic body unit  4363   b  is brought up against the ear from the side surface or the front surface, the electromagnetic vibrating element on the side brought up against the ear is made to vibrate and the vibration of the other one is turned off. Such independent control of the plurality of cartilage conduction vibration sources having different vibration directions is not limited to the case of the electromagnetic vibrating elements in  FIG. 72D ; rather, there are other possible cases of configurations in which, for example, the piezoelectric bimorph elements  4124  and  4126  of the forty-fifth embodiment illustrated in  FIG. 68  are utilized. 
       FIG. 73  is an enlarged cross-sectional view of the elements of the forty-eighth embodiment and the modification examples thereof.  FIG. 73A  enlarges the portions of the elastic body unit  4363   b  and the electromagnetic vibrating element  4324   a  of  FIG. 72B , and in particular provides a detailed illustration of the electromagnetic vibrating element  4324   a . The electromagnetic vibrating element  4324   a  has a yoke  4324   h  for holding a magnet  4324   f  and a central magnetic pole  4324   g  in a housing thereof, the yoke being suspended midair in a corrugation damper  4324   i . A top plate  4324   j , which has a gap, is anchored to the magnet  4324   f  and the central magnetic pole  4324   g . The magnet  4324   f , the central magnetic pole  4324   g , the yoke  4324   h , and the top plate  4324   j  become integrally movable in the vertical direction when viewed in  FIG. 73  relative to the housing of the electromagnetic vibrating element  4324   a . On the other hand, a voice coil bobbin  4324   k  is anchored to the inside of the housing of the electromagnetic vibrating element  4324   a , and a voice coil  4323   m  wrapped therearound penetrates into the gap of the top plate  4324   j . In such a configuration, when an audio signal is inputted into the voice coil  4323   m , relative displacement occurs between the yoke  4324   h  and the like, and the housing of the electromagnetic vibrating element  4324   a ; the vibration thereof is transmitted to the ear cartilage in contact therewith via the elastic body unit  4363   b.    
       FIG. 73B  illustrates a fourth modification example of the forty-eighth embodiment, and provides an enlarged illustration of the portions corresponding to  FIG. 73A . The internal configuration of the electromagnetic vibrating element  4324   a  is similar to that of  FIG. 73A ; therefore, to avoid complication, an illustration of the reference numerals of each unit has been omitted, and the description thereof has also been left out. The fourth modification example in  FIG. 73B  assumes a configuration in which the corner part of the mobile telephone  4401  is provided with a stepped unit  4401   g , the outer side thereof being covered by the elastic body unit  4463   b . The front surface side of the stepped unit  4401   g  is provided with a window unit  4401   f , the electromagnetic vibrating element  4324   a  being bonded to the rear side of the elastic body unit  4463   b  that faces the portion of the window unit  4401   f  A cushioning unit  4363   f  comprising an elastic body is also bonded to the opposite side of the electromagnetic vibrating element  4324   a . The cushioning unit  4363   f  is provided with a gap so as to not be in contact with the rear side of the stepped unit  4401   g  in the ordinary vibrating state, and acts as a cushioning material for preventing the elastic body unit  4463   b  thereabove from making contact with and being unrestrictedly pushed into the rear side of the stepped unit  4401   g  when there is an excessive push against the elastic body unit  4463   b  from collision with an external unit or the like. Adverse events such as when the electromagnetic vibrating element  4324   a  detaches due to deformation of the elastic body unit  4463   b  are thereby prevented. The cushioning unit  4363   f  functions as a balancer in the ordinary vibrating state, and therefore the shape and weight thereof or the like can be adjusted to design the electromagnetic vibrating element  4324   a  to have optimal acoustic properties. The cushioning unit  4363   f  may be a rigid body rather than an elastic body in a case of functioning only as a balancer. Although not depicted in  FIG. 73B , the corner part of the opposite side in the fourth modification example of the forty-eighth embodiment (corresponding to the position of the elastic body unit  4363   a  in  FIG. 72B ) also assumes a configuration having left-right symmetry with  FIG. 73B . 
     The fourth modification example in  FIG. 73B  is based on the arrangement of the electromagnetic vibrating elements in the orientation in  FIG. 72B . However, a configuration such as that of the fourth modification is not limited thereto, and can also be applied to the arrangement of the electromagnetic vibrating elements in the various orientations in  FIGS. 72C to 72E . 
     In the forty-eighth embodiment illustrated in  FIGS. 72 and 73A , the elastic body unit  4363   b  and the electromagnetic vibrating element  4324   a  are configured as replaceable unit parts. When the outer appearance of the elastic body unit  4363   b  is sullied by collision with an external unit, in terms of aesthetics, the elastic body unit  4363   b  and the electromagnetic vibrating element  4324   a  can be replaced as a unit. This is a point of similarity with the fourth modification example of the forty-eighth embodiment illustrated in  FIG. 73B  as well; the elastic body unit  4463   b , the electromagnetic vibrating element  4324   a , and the cushioning unit  4363   f  are configured as a replaceable unit part. When the outer appearance of the elastic body unit  4463   b  is damaged in terms of aesthetics, the whole can be replaced as a unit. Such a configuration as a unit part is a useful feature that is consistent with the fact that the elastic body unit  4463   b  or the like is configured as a protector and is a part positioned at a corner part predicted to collide with an external unit. The configuration is also a useful feature that is consistent with the fact that the corner susceptible to collision is a suitable location for making contact for cartilage conduction. Furthermore, the feature in which the cartilage conduction vibration units are configured as replaceable unit parts is fundamentally consistent with the configuration of the other portions of the mobile telephone, and is useful in providing a commercial product to which cartilage conduction vibration units having acoustic properties that are optimized in accordance with the user&#39;s age or other parameters (for example, where the shape and/or weight of the cushioning unit  4363   f  illustrated in  FIG. 73B  are adjusted) are attached. The feature is also fundamentally consistent with the configuration of the other portions of the mobile telephone and is useful in providing a commercial product that can be modified not only for acoustic properties but also in accordance with user preferences; for example, in accordance with a request regarding which of the cartilage conduction vibration units from  FIGS. 72B to 72E  is used. 
     The specific configuration in which the cartilage conduction vibration source is provided to the elastic body unit of the corner part is not limited to what is illustrated in  FIG. 73 ; the design can be modified where appropriate. For example, the cushioning unit  4363   f  illustrated in  FIG. 73B  may be bonded to the rear side of the stepped unit  4401   g , instead of being bonded to the opposite side of the electromagnetic vibrating element  4324   a . In such a case, the cushioning unit  4363   f  is provided with a gap so as to prevent contact with the opposite side of the electromagnetic vibrating element  4324   a  in the ordinary vibrating state. The cushioning unit  4363   f  may also be omitted in a case in which the elastic body unit  4463   b  is able to withstand pushing due to collision with an external unit or another cause. 
     The various features of each of the embodiments described above are not to be limited to the above embodiments; rather, wherever it is possible to benefit from the feature of an embodiment, same can also be implemented in other embodiments. The various features of each of the embodiments described above are not to be restricted to individual respective embodiments, but rather can be substituted or combined with other appropriate embodiments. The forty-eighth embodiment and the modification examples thereof serve as illustrations of examples in which the electromagnetic vibrating element is utilized as a cartilage conduction vibration unit and in which independently controllable and separate electromagnetic vibrating elements are provided to the elastic body units at different corners. However, the implementation of the present invention is not to be limited thereto. For example, in a case in which, as has already been described, a piezoelectric bimorph element is utilized as the cartilage conduction vibration unit, the cartilage conduction vibration units separately provided to different corners as in the first embodiment of  FIG. 1  can be controlled independent of each other. In such a case, referring to the forty-eighth embodiment, the piezoelectric bimorph element can also be provided to the elastic body units at different corners. Conversely, even a case in which an electromagnetic vibrating element is utilized as the cartilage conduction vibration unit can be configured such that the vibration of a single electromagnetic vibrating element is transmitted to the left and right corners, as in the fourth embodiment of  FIG. 7 , the fifth embodiment of  FIG. 11 , the tenth embodiment of  FIG. 19 , the eleventh embodiment of  FIG. 20 , and the like. In such a case, referring to the forty-eighth embodiment, the vibration conductors to the left and right corner parts can be constituted of elastic bodies regardless of whether the cartilage conduction vibration unit is a piezoelectric bimorph element or an electromagnetic vibrating element. Also, referring to the forty-sixth embodiment and the modification examples thereof, the configuration may be such that the two sides of the electromagnetic vibrating element are supported by elastic bodies provided to the left and right corner parts, depending on the shape of the electromagnetic vibrating element. 
     Forty-Ninth Embodiment 
       FIG. 74  is a perspective view and a cross-sectional view relating to a forty-ninth embodiment according to an aspect of the present invention as well as to a modification example thereof, and is configured as a mobile telephone  4501 . The forty-ninth embodiment is consistent with the forty-sixth embodiment of  FIG. 69  except for the configuration for switching air conduction (to be described later); therefore, like reference numerals have been assigned and the description thereof is called upon. More specifically, the forty-ninth embodiment is illustrated in  FIGS. 74A to 74D , of which  FIGS. 74A to 74C  correspond to  FIGS. 69A to 69C , which relate to the forty-sixth embodiment.  FIG. 74D  is an enlarged view of the elements of  FIG. 74C .  FIG. 74E  is an enlarged view of the elements relating to a modification of the forty-ninth embodiment. 
     As is clear from the B 2 -B 2  cross-sectional view of  FIG. 74C , the forty-ninth embodiment is provided with a transparent resonance chamber  4563  such that the display unit  3405  is covered. The transparent resonance chamber  4563  has air removal holes partially provided to the interior side of the mobile telephone  4501  in the hollow. The transparent resonance chamber  4563  is extremely thin, and therefore the user can observe the display unit  3405  through the transparent resonance chamber  4563 . As is clear from  FIGS. 74B and 74C , the middle portion of the piezoelectric bimorph element  2525  is provided with a vibration conductor  4527  that can slide in the vertical direction. When the vibration conductor  4527  is at the position indicated by the solid line illustrated in  FIG. 74C , the transmission of vibration from the middle portion of the piezoelectric bimorph element  2525  to the transparent resonance chamber  4563  is cut off, and when the vibration conductor  4527  is at the position indicated by the dotted line in  FIG. 74C  and comes into contact with the upper part of the transparent resonance chamber  4563 , the vibration of the middle portion of the piezoelectric bimorph element  2525  is transmitted to the transparent resonance chamber  4563  via the vibration conductor  4527 , whereby air conduction sound is generated from the entire transparent resonance chamber  4563  and the entire transparent resonance chamber  4563  becomes a surface speaker. This aspect is clearly illustrated by the enlarged view of the elements of  FIG. 74D . The up and down of the vibration conductor  4527  is performed by causing an external manual operation knob  4527   a  of the mobile telephone  4501  to slide up and down. The manual operation knob  4527   a  has a click function for determining the two up-down positions. The vibration conductor  4527  also is resilient so as to effectively make contact with the transparent resonance chamber  4563  when made to slide to the position of the dotted line. 
     As described above, air conduction sound is generated from the entire transparent resonance chamber  4563  and cartilage conduction is generated from the elastic body units  4263   a  and  4263   b  in the state in which the vibration conductor  4527  is at the position indicated by the dotted line in  FIGS. 74C to 74D . The user can accordingly bring the elastic body unit  4263   a  or  4263   b  up against to ear to listen to sound by cartilage conduction, and can also bring any desired portion of the display unit  3405  to which the transparent resonance chamber  4563  is provided close to or up against the ear to listen to sound by air conduction. In this manner, a variety of uses become possible in accordance with the user&#39;s preferences and status. On the other hand, the transmission of vibration to the transparent resonance chamber  4563  is cut off and the generation of air conduction sound from the transparent resonance chamber  4563  can be stopped in the state in which the vibration conductor  4527  is at the position indicated by the solid line illustrated in  FIGS. 74C to 74D ; therefore, because sound leakage by air conduction is prevented, particularly in the state in which the environment is quiet, it is possible to listen to sound by cartilage conduction while preventing any disturbance to the surroundings or leakage of sensitive information. 
     The modification example of the forty-ninth embodiment in  FIG. 74E  is configured such that a vibration conductor  4527   b  is made to rotate, whereby vibration from the middle portion of the piezoelectric bimorph element  2525  is intermittently transmitted to the transparent resonance chamber  4563 . Specifically, when the vibration conductor  4527   b  is at the position indicated by the solid line illustrated in  FIG. 74E , the vibration conductor  4527   b  separates from both the middle portion of the piezoelectric bimorph element  2525  and the transparent resonance chamber  4563 , and the transmission of vibration is cut off. On the other hand, when the vibration conductor  4527   b  is rotated clockwise and is at the position indicated by the dotted line in  FIG. 74E , the vibration conductor  4527   b  is in contact with both the middle portion of the piezoelectric bimorph element  2525  and the upper part of the transparent resonance chamber  4563 , and the vibration of the middle portion of the piezoelectric bimorph element  2525  is transmitted to the transparent resonance chamber  4563  via the vibration conductor  4527   b . This modification example is otherwise similar to the forty-ninth embodiment of  FIGS. 74A to 74D . The rotation of the vibration conductor  4527   b  is performed by the rotation of an external manual operation dial  4527   c  of the mobile telephone  4501 . The manual operation dial  4527   c  has a click function for determining the two positions of the rotation. The vibration conductor  4527   b  is resilient as well, and, when rotated to the position of the dotted line, presses effectively against the middle portion of the piezoelectric bimorph element  2525  and the upper part of the transparent resonance chamber  4563 . 
     Switching between cartilage conduction and air conduction in the manner described above is not to be limited to the forty-ninth embodiment illustrated in  FIG. 74  and to the modification examples thereof various configurations are possible. For example, in  FIG. 74 , the piezoelectric bimorph element  2525  and the transparent resonance chamber  4563  are secured, and the vibration conductor  4527  or  4527   b  is moved therebetween, whereby intermittent vibration is performed. However, intermittent vibration between the two can also be performed instead by rendering at least one of the piezoelectric bimorph element  2525  and the transparent resonance chamber  4563  movable. The movement at this time may be performed by at least a part of either the piezoelectric bimorph element  2525  or the transparent resonance chamber  4563 . Furthermore,  FIG. 74  serves to illustrate an example of switching between the case of cartilage conduction together with air conduction and the case of only cartilage conduction (to be precise, there is also a slight air conduction component, but for the sake of simplicity, this case is hereinafter referred to as “only cartilage conduction”), but another possible configuration is one in which, in exchange, the switching is between a case of only cartilage conduction and a case of only air conduction or the switching is between a case of cartilage conduction together with air conduction and a case of only air conduction. Also,  FIG. 74  serves to illustrate an example of manual switching, but another possible configuration is one in which a noise sensor for differentiating between whether the environment is quiet or not is provided and the vibration conductor  4527  or  4527   b  is automatically driven on the basis of the output of the noise sensor, whereby a case of cartilage conduction together with air conduction is automatically switched to a case of cartilage conduction only when the noise detected by the noise sensor is at or above a predetermined level. 
     Fiftieth Embodiment 
       FIG. 75  is a block diagram relating to a fiftieth embodiment according to an aspect of the present invention, and is configured as a mobile telephone  4601 . The fiftieth embodiment is based on the configuration of the third modification example of the forty-eighth embodiment, the cross-section of which is illustrated in  FIG. 72E ; the electromagnetic vibrating elements  4326   d ,  4326   e ,  4324   d , and  4324   e  thereof are controlled by a configuration that is substantially consistent with the block diagram of the first embodiment in  FIG. 3 . In terms of the need to describe the arrangement, the portions of the electromagnetic vibrating elements are illustrated by a composite of the cross-sectional views. Because the fiftieth embodiment is configured as described above, portions in  FIG. 75  that are shared with  FIGS. 3 and 72E  are assigned shared reference numerals, and a description thereof has been left out, except where necessary. The fiftieth embodiment is not provided with any incoming-talk unit other than the electromagnetic vibrating elements  4326   d ,  4326   e ,  4324   d , and  4324   e , and therefore the phase adjustment mixer unit  36 , a right ear drive unit  4624 , a left ear drive unit  4626 , a reduced air conduction automatic switching unit  4636 , and the electromagnetic vibrating elements  4326   d ,  4326   e ,  4324   d , and  4324   e  (which are illustrated in  FIG. 75 ) constitute the incoming-talk unit in the telephone function unit  45  (which in  FIG. 3  is the incoming-talk unit  13 ). The fiftieth embodiment configured in the manner described above assumes separate embodiments relating to the switch between cartilage conduction and air conduction illustrated in the forty-ninth embodiment, the switch being performed both electrically and automatically. The following description focuses on this point. 
     As described in  FIG. 72E  as well, the fiftieth embodiment of  FIG. 75  assumes a configuration in which cartilage conduction is respectively generated from a plurality of different electromagnetic vibrating elements  4326   e ,  4326   d ,  4324   e , and  4324   d , to the side surface and the front surface. The pair of electromagnetic vibrating elements  4326   d  and  4326   e , which are embedded in the elastic body unit  4363   a , are controlled by the left ear drive unit  4262 , and the pair of electromagnetic vibrating elements  4324   d  and  4324   e , which are embedded in the elastic body unit  4363   b , are controlled by the right ear drive unit  4264 . In such a configuration, similarly with respect to the first embodiment, the acceleration sensor  49  is used to detect which of the elastic body unit  4363   a  and the elastic body unit  4363   b  is in a state of being brought up against an ear, where either the right ear drive unit  4624  or the left ear drive unit  4626  is turned on and the other is turned off. In addition, either the pair of electromagnetic vibrating elements  4326   d  and  4326   e  or the pair of electromagnetic vibrating elements  4324   d  and  4324   e  is rendered able to vibrate and the other is rendered unable to vibrate. 
     The fiftieth embodiment of  FIG. 75  is further provided with an environment-noise microphone  4638  for differentiating between whether or not the environment is quiet. When the noise detected by the environment-noise microphone  4638  is at or above a predetermined level, the reduced air conduction automatic switching unit  4636  functions according to a command from the controller  39  and causes the pair of electromagnetic vibrating elements  4326   d  and  4326   e  or the pair of electromagnetic vibrating elements  4324   d  and  4324   e  to vibrate. On the other hand, in a quiet situation, which is determined by the controller  39  when the noise detected by the environment-noise microphone  4638  is at or below a predetermined level, only the electromagnetic vibrating element  4326   d  or the only the electromagnetic vibrating element  4324   d  is made to vibrate, according to the function of the reduced air conduction switching unit  4636 , and the vibration of the electromagnetic vibrating elements  4326   e  and  4324   e  is stopped. However, for the purpose of detecting the magnitude of environment noise, instead of there being separately provided a dedicated environment-noise microphone  4638  such as in  FIG. 75 , the microphone output in the outgoing-talk unit  23  of the telephone function unit  45  may be used to extract the noise component. The extracting can be performed by analyzing the frequency spectrum of the microphone output, utilizing the microphone output from when audio is interrupted, or the like. 
     The following is a description of the significance of the configuration described above. As illustrated in  FIG. 72E  as well, the vibration direction of the electromagnetic vibrating elements  4326   d  and  4324   d  in the fiftieth embodiment of  FIG. 75  is the direction perpendicular to the side surface, and the vibration direction of the electromagnetic vibrating elements  4326   e  and  4324   e  is the direction perpendicular to the front surface. Because the electromagnetic vibrating elements  4326   e  and  4324   e  vibrate in the direction perpendicular to the front surface on which the display unit  5  or the like is arranged, the entire front surface, which in the mobile telephone  4601  has a large surface area, resonates and has a larger vibration component than the vibration of the side surface from the electromagnetic vibrating elements  4326   d  and  4324   d . For this reason, and with respect to the forty-ninth embodiment, the case in which the pair of electromagnetic vibrating elements  4326   e  and  4326   d  vibrate or the case in which the pair of electromagnetic vibrating elements  4324   e  and  4324   d  vibrate corresponds to the “case of cartilage conduction plus air conduction.” On the other hand, the case in which only the electromagnetic vibrating element  4326   d  vibrates or the case in which only the electromagnetic vibrating element  4324   d  vibrates corresponds to the “case of cartilage conduction only.” However, a certain amount of an air conduction component remains in the “case of cartilage conduction only,” as has been described in the forty-ninth embodiment, and therefore the distinction between these cases is based on a strictly relative comparison of the size of the air conduction component. 
     As has been described above, in a case in which the electromagnetic vibrating elements  4326   e  and  4326   d  vibrate or in a case in which the electromagnetic resonators  4324   e  and  4324   d  vibrate, the user can bring the elastic body unit  4263   a  or  4263   b  against the ear to listen to sound by cartilage conduction, and can also bring any desired portion of the front surface of the mobile telephone  4601  close to or up against the ear to listen to sound by air conduction. In this manner, a variety of uses become possible in accordance with the user&#39;s preferences and status. On the other hand, in a case in which only the electromagnetic vibrating element  4326   d  vibrates or in a case in which only the electromagnetic vibrating element  4324   d  vibrates, because relatively less air conduction is generated and sound leakage by air conduction is prevented, particularly in the state in which the environment is quiet, it is possible to listen to sound by cartilage conduction while preventing any disturbance to the surroundings or leakage of sensitive information. In the fiftieth embodiment, air conduction is automatically reduced in a state in which the environment is quiet, due to the functions of the environment-noise microphone  4638  and the reduced air conduction automatic switching unit  4636 . 
     Although the fiftieth embodiment of  FIG. 75  is configured using electromagnetic vibrating elements, the configuration for electrically and automatically switching between cartilage conduction and air conduction is not limited to the case in which the electromagnetic vibrating elements are used as cartilage conduction vibration sources. For example, as in the forty-fifth embodiment of  FIG. 68 , in a case in which a plurality of independently controllable piezoelectric bimorph elements are provided to mutually different directions, the same can be automatically controlled in conformity with the fiftieth embodiment. Another possible configuration in the fiftieth embodiment of  FIG. 75  is one in which a transparent resonance chamber  4563  for generating air conduction is provided, such as in the forty-ninth embodiment of  FIG. 74 , and one or both of the electromagnetic vibrating element  4326   e  and the electromagnetic vibrating element  4324   e  is brought into constant contact with such a transparent resonance chamber  4563 , whereby air conduction is actively generated from the front surface of the mobile telephone  4601 . 
     The various features of the embodiments described above are not limited to implementation in the aforedescribed embodiments, and may be implemented in other aspects as well, provided that the advantages thereof can be enjoyed by doing so. Moreover, the various features of the embodiments are not limited to implementation in their individual embodiments, and combinations which incorporate features of other embodiments, as appropriate, are acceptable. The various features of each of the embodiments described above are not to be limited to the above embodiments; rather, wherever it is possible to benefit from the feature of an embodiment, the same can also be implemented in other embodiments. The various features of each of the embodiments are not to be restricted to individual respective embodiments, but rather can be substituted or combined with other appropriate embodiments. For example, in the present invention, ear-contacting units for cartilage conduction are provided to the corner parts of the mobile telephone. This feature will now be considered, for example, for the mobile telephone  301  configured as a smartphone as in the fourth embodiment of  FIG. 7  (which hereinafter is referred to as the smartphone  301 , for the sake of simplicity). The smartphone  301  as in  FIG. 7  has a large-screen display unit  205  provided with GUI functions on the front surface thereof, and assumes an arrangement in which an ordinary incoming-talk unit  13  is relegated to the upper angled region of the smartphone  301 . Moreover, since the ordinary incoming-talk unit  13  is provided to the middle portion of the part of the smartphone  301 , there is assumed an arrangement in which it is difficult to bring the large-screen display unit  205  up against the cheek bone and to bring the incoming-talk unit  13  close to the ear in a case in which the smartphone  301  is brought up against the ear; and pressing the ordinary incoming-talk unit  13  strongly against the ear so that the voice of the other party can be better heard incurs a result where the large-screen display unit  205  is in contact with the ear or cheek and is fouled by sebum or the like. By contrast, when the right ear vibration unit  224  and the left ear vibration unit  226  are arranged at the corner parts of the smartphone  301  in  FIG. 7 , as is illustrated in  FIG. 2  which relates to the first embodiment, the corner parts of the smartphone  301  are accommodated in the recess around the entrance to the external auditory meatus in the vicinity of the tragus  32 . It thereby becomes possible to readily push the audio output unit of the smartphone  301  against the area around the entrance to the external auditory meatus, and contact made by the large-screen display unit  205  with the ear or cheek can be naturally avoided even in a case of strong pushing. Such an arrangement of the audio output unit at the corner part of the mobile telephone is not limited to the case of using cartilage conduction, and is useful also in a case of an incoming-talk unit that uses an ordinary air conduction speaker. In such a case, air conduction speakers for right ear use and left ear use are preferably provided to the two corners of the upper part of the smartphone. 
     As has already been described, cartilage conduction conducts differently depending on the amount of force pushing on the cartilage, and a state of effective conduction can be obtained by increasing the amount of force that is pushing. This means that when it is difficult to hear the incoming sound, a natural behavior such as increasing the force pushing the mobile telephone against the ear can be utilized to adjust the volume. Furthermore, when the amount of pushing force is increased until a state in which the hole of the ear is obstructed, the volume is further increased due to the earplug bone conduction effect. Even when such a function is not explained to the user in, for example, the instruction manual, the user can still intuitively understand the function through natural behavior. Such an advantage in terms of usage can also be achieved in an artificial sense in a case of an incoming-talk unit in which an ordinary air conduction speaker is used, without the cartilage conduction vibration unit being used as the audio output unit, and can serve as a useful feature of the mobile telephone. 
     Fifty-First Embodiment 
       FIG. 76  is a block diagram relating to a fifty-first embodiment according to an aspect of the present invention, and is configured as a mobile telephone  4701 . The fifty-first embodiment does not utilize a cartilage conduction vibration unit as the audio output unit as described above but rather uses an ordinary air conduction speaker, and is configured such that automatic volume adjustment can be artificially achieved by a natural behavior. In terms of the need to describe the arrangement of the outer appearance, a composite schematic view of the mobile telephone is illustrated in the block diagram. The majority of the block diagram of  FIG. 76  is consistent with the first embodiment of  FIG. 3 , and the majority of the general overview is consistent with the fourth embodiment of  FIG. 7 ; therefore, portions in common have been given like reference numerals, and a description thereof has been left out except where necessary. A volume/acoustics automatic adjustment unit  4736 , a right ear drive unit  4724 , a left ear drive unit  4726 , a right ear air conduction speaker  4724   a , and a left ear air conduction speaker  4726   a  illustrated in  FIG. 76  constitute the incoming-talk unit in the telephone function unit  45  (which in  FIG. 3  is the outgoing-talk unit  13 ). 
     The right ear air conduction speaker  4724   a  of the fifty-first embodiment in  FIG. 76  is controlled by the right ear drive unit  4524 , and the left ear air conduction speaker  4726   a  is controlled by the right ear drive unit  4526 . Also, similarly with respect to the fiftieth embodiment, the acceleration sensor  49  is used to detect which of the right ear air conduction speaker  4724   a  and the left ear air conduction speaker  4726   a  is in a state of being brought up against an ear, where either the right ear drive unit  4524  or the left ear drive unit  4526  is turned on and the other is turned off. In addition, either the right ear air conduction speaker  4724   a  or the left ear air conduction speaker  4726   a  is turned on and the other is turned off. 
     A right ear pressure sensor  4742   a  and a left ear pressure sensor  4742   b  are respectively provided to the vicinity of the right ear air conduction speaker  4724   a  and the left ear air conduction speaker  4726   a  and detect pressure on whichever of the right ear air conduction speaker  4724   a  or left ear air conduction speaker  4726   a  is turned on. A left/right pressure sensor processing unit  4742  analyzes the magnitude of the detected pressure and sends volume/acoustics control data to the controller  39 . The controller  39  commands a volume/acoustics automatic adjustment unit  4736  on the basis of the volume/acoustics control data and automatically adjusts the volume of whichever of the right ear drive unit  4524  or left ear drive unit  4526  is on. The volume is basically adjusted such that the volume increases with an increase in pressure and, when it is difficult to listen to the incoming-talk unit sound, is set so as to be a suitable response to a natural behavior such as increasing the force pushing the mobile telephone  4701  against the ear. 
     A supplementary detailed description of the function of the volume/acoustics automatic adjustment unit  4736  will now be provided. To avoid unstable volume changes due to changes in pressure, first, volume changes are configured such that the volume only undergoes stepwise changes in the increasing direction and in accordance only with an increase in pressure. Furthermore, to avoid unintentional volume changes, the volume/acoustics automatic adjustment unit  4736  is configured such that volume increases in a stepwise manner in reaction only to when a predetermined pressure increase lasts on average for a predetermined period of time (for example, 0.5 seconds) or longer. The volume/acoustics automatic adjustment unit  4736  is also configured such that volume is instantaneously lowered to a baseline state in a case in which it is detected that the state in which the pressure has fallen to a predetermined value (corresponding to the state in which whichever of the right ear air conduction speaker  4724   a  or left ear air conduction speaker  4726   a  is turned on is brought away from the ear) or lower has lasted for a predetermined period of time (for example, 1 second) or longer. The user is thereby able to intentionally bring the mobile telephone  4701  slightly away from the ear in a case in which the volume has been excessively increased or the like (which is also consistent with a natural operation such as bringing a sound source away from the ear when the sound is too loud), and once the volume has been reset to the baseline state, the force of the pressure is again increased to achieve a desired volume. 
     The volume/acoustics automatic adjustment unit  4736  is further able to automatically adjust the acoustics. This function is related to the environment-noise microphone  38  described in relation to the first embodiment in  FIG. 3 . Namely, in the first embodiment, the environment noise picked up by the environment-noise microphone  38 , is mixed into the right-ear cartilage-conduction vibration unit  24  and the left-ear cartilage-conduction vibration unit  26  upon undergoing wavelength inversion; the environment noise, which is contained in the audio information through the incoming-talk unit  13 , is canceled and the audio information of the party on the line becomes easier to comprehend through listening. The volume/acoustics automatic adjustment unit  4736  in the fifty-first embodiment utilizes this function to turn the noise-canceling function off when the pressure is equal to or less than a predetermined value and to turn the noise-canceling function on when the pressure is equal to or above a predetermined value. The degree to which the environment noise inversion signal is mixed can also be adjusted in a stepwise manner, whereby the noise-canceling function, rather than merely being turned on and off, can also undergo continuous or stepwise increases and decreases. In this manner, the volume/acoustics automatic adjustment unit  4736  is capable of automatically adjusting not only the volume but also the acoustics, on the basis of the output of the left/right pressure sensor processing unit  4742 . The fifty-first embodiment of  FIG. 76  is an embodiment that serves to illustrate that the aforementioned advantage, in which the right ear audio output unit and the left ear audio output unit are arranged at the corner parts of the smartphone, is not limited to a case in which cartilage conduction is used; benefits may also accrue therefrom in a case in which an outgoing-talk unit using ordinary air conduction speakers is utilized. 
     The various features of the embodiments described above are not limited to implementation in the aforedescribed embodiments, and may be implemented in other aspects as well, provided that the advantages thereof can be enjoyed by doing so. Moreover, the various features of the embodiments are not limited to implementation in their individual embodiments, and combinations which incorporate features of other embodiments, as appropriate, are acceptable. The various features of each of the embodiments described above are not to be limited to the above embodiments; rather, wherever it is possible to benefit from the feature of an embodiment, the same can also be implemented in other embodiments. The various features of each of the embodiments are not to be restricted to individual respective embodiments, but rather can be substituted or combined with other appropriate embodiments. For example, in the fifty-first embodiment of  FIG. 76 , a determination is made as to which of the right ear air conduction speaker  4724   a  or left ear air conduction speaker  4726   a  is to be turned on according to the output of the acceleration sensor  49 , but the configuration may be such that the outputs of the right ear pressure sensor  4742   a  and left ear pressure sensor  4742   b  are used to turn on whichever of the right ear air conduction speaker  4724   a  or left ear air conduction speaker  4726   a  has more pressure, and to turn the other off. 
     Also, the fifty-first embodiment of  FIG. 76  is provided with the right ear air conduction speaker  4724   a  and the left ear air conduction speaker  4726   a  as well as the right ear pressure sensor  4742   a  and left ear pressure sensor  4742   b  corresponding thereto, but when there is only the purpose of automatic volume/acoustics adjustment by pressure, then a single conventional air conduction speaker may be provided to the middle of the upper part of the mobile telephone, and a single pressure sensor may be provided correspondingly with respect thereto. Furthermore, the fifty-first embodiment of  FIG. 76  has illustrated how environment noise is canceled out by waveform inversion as a fundamental configuration of the automatic adjustment of acoustics by the volume/acoustics automatic adjustment unit  4736 , but such a configuration is not provided by way of limitation. For example, the configuration may be such that the volume/acoustics automatic adjustment unit  4736  is provided with a filter for cutting out environment noise (for example, a low-frequency-band-cutting filter), the filter being turned off when the pressure is at or below a predetermined value and the filter function being turned on when the pressure is at or above a predetermined value. The configuration may also be such that, instead of a low-frequency band or the like being cut out by the filter, the gain of the low-frequency band is dropped (or the gain of a high frequency area is raised). The filter function or the frequency-band-selective gain function can also be adjusted in a stepwise manner, whereby the filter function or the frequency-selective gain function, rather than merely being turned on and off, can also alter the environment noise reduction capability in a stepwise or continuous manner in accordance with the pressure. 
     MODES FOR CARRYING OUT THE INVENTION 
     Fifty-Second Embodiment 
       FIG. 77  is a cross-sectional view relating to a fifty-second embodiment according to an aspect of the present invention, and is configured as a mobile telephone  4801 .  FIG. 77  provides a cross-sectional view of the mobile telephone  4801 , depicted in order to describe the support structure and arrangement of piezoelectric bimorph elements  2525   a  and  2525   b  serving as cartilage conduction vibration sources, while the interior of the cross-sectional view, which relates to the control of the mobile telephone, depicts not an actual arrangement but rather a block diagram. The block diagram portion, being founded on the block diagram of the first embodiment illustrated in  FIG. 3 , essentially omits a depiction of shared portions, with the exception of those needed to understand the interrelationships, and like portions, when depicted, have been assigned like reference numerals, a description thereof being omitted unless needed. 
     The fifty-second embodiment of  FIG. 77 , similarly with respect to the forty-ninth embodiment of  FIG. 74  and the fiftieth embodiment of  FIG. 75 , is configured as an embodiment permitting the interchange of “the case of cartilage conduction plus air conduction” and “the case of cartilage conduction only.” Further, the fifty-second embodiment of  FIG. 77 , similarly with respect to the forty-sixth embodiment of  FIG. 69 , has elastic body units  4863   a ,  4863   b ,  4863   c , and  4863   d  serving as protectors provided to the four corners susceptible to impact when the mobile telephone  4801  is accidentally dropped. However, rather than a two-sided support structure for the elastic body units  4863   a ,  4863   b  to support the piezoelectric bimorph elements  2525   a  and  2525   b , a single side thereof is supported on a cantilever structure, similarly with respect to the forty-second embodiment of  FIG. 65  and the forty-third embodiment of  FIG. 66 . As above, the fifty-second embodiment of  FIG. 77  is related to features of various embodiments having already been described, wherefore a repetitive description of the individual features has been avoided unless needed, since the same are readily understood from the descriptions of the corresponding embodiments. 
     First, the structure and arrangement of the fifty-second embodiment of  FIG. 77  will now be described. As has already been mentioned, the four corners of the mobile telephone  4801  are provided with the elastic body units  4863   a ,  4863   b ,  4863   c , and  4863   d , serving as protectors. The outer sides of the corners of such elastic members are beveled in a smooth convex shape to prevent the occurrence of slight pain when held against the ear cartilage. Although a more detailed description will also be provided later, the shape of the corner parts allows for a suitable fit with the cartilage around the external auditory meatus and for comfortable listening by cartilage conduction. 
     In the fifty-second embodiment of  FIG. 77 , the piezoelectric bimorph element  2525   b  for the right ear and the piezoelectric bimorph element  2525   a  for the left ear are employed as described above, and can be controlled separately, similarly with respect to the first embodiment illustrated in  FIGS. 1 to 4 . The piezoelectric bimorph elements  2525   b  and  2525   a  are appropriately long enough to obtain suitable frequency output properties, but in order for both to be compactly arranged within the mobile telephone  4801 , the piezoelectric bimorph element  2525   b  for the right ear, as illustrated in  FIG. 77 , is laid horizontally, the end to which no terminal is provided being supported by the elastic body unit  4863   b . On the other hand, the piezoelectric bimorph element  2525   a  for the left ear is stood upright, the end to which no terminal is provided being supported by the elastic body unit  4863   a  (however, the vertical and horizontal arrangement of the piezoelectric bimorph elements for the right ear and for the left ear may be inverted from the description above). A terminal is provided to the other ends of each of the piezoelectric bimorph elements  2525   b  and  2525   a , but serves as a free end in terms of the support structure due to the connection thereof with the controller  39  by a flexible lead. In this manner, the vibration of the free ends of the piezoelectric bimorph elements  2525   b  and  2525   a  exhibits opposite actions on the elastic body unit  4863   b  and the elastic body  4863   a , and cartilage conduction can be obtained by bringing the same into contact with the ear cartilage. The primary vibration direction of the piezoelectric bimorph elements  2525   b  and  2525   a  is the direction perpendicular to the plan in  FIG. 77 . 
     Next, the manner in which the piezoelectric bimorph elements  2525   b  and  2525   a  are controlled will be described. The piezoelectric bimorph element  2525   b  for the right ear, which is supported by the elastic body unit  4863   b , is driven by a right ear amplifier  4824  via a switch  4824   a . On the other hand, the piezoelectric bimorph element  2525   a  for the left ear, which is supported by the elastic body unit  4863   a , is driven by a left ear amplifier  4826  via a switch  4826   a . An audio signal from the phase adjustment mixer unit  36  is inputted into the right ear amplifier  4824  and the left ear amplifier  4826 ; the audio signal to the left ear amplifier  4826  is phase-inverted by a waveform inverter  4836   b  and then inputted via a switch  4836   a . As a result, in the state depicted in  FIG. 77 , vibrations having mutually inverted phases are conducted to and mutually canceled out in the chassis of the mobile telephone  4801  from the elastic body unit  4863   a  and the elastic body unit  4863   b , and the generation of air conduction sound from the entire surface of the chassis of the mobile telephone  4801  is substantially eliminated. 
     In a case where, for example, the cartilage of the right ear is brought into contact with the elastic body unit  4863   b , there will be direct cartilage conduction to the ear cartilage from the elastic body  4863   b , whereas, by contrast, the vibration of the elastic body unit  4863   a  reaches the elastic body unit  4863   b  and is conducted to the ear cartilage as cartilage conduction only after having been first conducted to the chassis of the mobile telephone  4801 . Accordingly, since a difference emerges in the intensities of the phase-inverted vibrations, the difference will be conducted to the ear cartilage as cartilage conduction from the elastic body unit  4863   b  without having been canceled out. The same is also true of a case where the cartilage of the left ear is brought into contact with the elastic body unit  4863   a . Accordingly, the state depicted in  FIG. 77  in the fifty-second embodiment becomes a state corresponding to the “case of cartilage conduction only” in the forty-ninth embodiment of  FIG. 74  and the fiftieth embodiment of  FIG. 75 . An air conduction eliminating gain adjustment unit  4836   c  serves to adjust the gain of the left ear amplifier  4826  so as to cancel out vibration to the chassis of the mobile telephone  4801  from the elastic body unit  4863   a  and the elastic body unit  4863   b  as described above, whereby the generation of air conduction sound will be minimized. Also, rather than being provided to the left ear amplifier  4826  side, the aforesaid switch  4836   a , waveform inverter  4836   b , and air conduction eliminating gain adjustment unit  4836   c  may also be instead provided to the right ear amplifier  4824  side. Alternatively, the air conduction eliminating gain adjustment unit  4836   c  only may be provided to the right ear amplifier  4824  side. 
     The fifty-second embodiment of  FIG. 77  is provided with the environment-noise microphone  4638  for determining whether or not the environment is silent. When the noise detected by the environment-noise microphone  4638  is at or above a predetermined amount, the switch  4836   a  is switched to a signal pathway (the lower one in  FIG. 77 ) by a command from the controller  39 . An audio signal from the phase adjustment mixer unit  36  is thereby conducted to the left ear amplifier  4826  without waveform inversion. At such a time, the vibration conducted to the chassis of the mobile telephone  4801  from the elastic body unit  4863   a  and the elastic body unit  4863   b  is not canceled out, but rather air conduction sound from the entire surface of the chassis of the mobile telephone  4801  is conversely generated at a two-fold increase. Such a state serves as a state corresponding to the “case of cartilage conduction plus air conduction” in the forty-ninth embodiment of  FIG. 74  and the fiftieth embodiment of  FIG. 75 . Because of the two-fold increase in air conduction sound from the entire surface of the chassis, such a state is suitable for a case where the mobile telephone  4801  is taken away from the ear and audio is listened to, as is done during a videoconferencing function or similar circumstances; in the case of the videoconferencing function mode, the switch  4836   a  is switched to the signal pathway (the lower one in  FIG. 77 ) by a command from the controller  39  irrespective of the detection of the environment-noise microphone  4638 . 
     In circumstances determined to be silent by the controller  39  when the noise detected by the environment-noise microphone  4638  is at or below a predetermined amount, the switch  4836   a  is switched to the state depicted in  FIG. 77  by a command from the controller  39 . As described above, the vibrations conducted to the chassis of the mobile telephone  4801  from the elastic body unit  4863   a  and the elastic body unit  4863   b  are thereby mutually canceled out, substantially eliminating the generation of air conduction sound, which serves as a state corresponding to the “case of cartilage conduction only.” 
     Further, similarly with respect to the first embodiment, it is possible in the fifty-second embodiment of  FIG. 77  for the state of whether the elastic body unit  4863   a  or the elastic body unit  4863   b  has been brought up against the ear to be detected by an acceleration sensor  49 , and for the switch  4824   a  and a switch  4826   a  to be controlled by the control of the controller  39 . Then, the operation unit  9  can be used to switch between a two-sided always-on mode in which both the switch  4824   a  and the switch  4826   a  are on irrespective of the state detected by the acceleration sensor  49 , and a one-sided on mode in which one of either the switch  4824   a  or the switch  4826   a  is turned on and the other is turned off on the basis of the state detected by the acceleration sensor  49 . In the one-sided on mode, for example, the switch  4824   a  is turned on and the switch  4826   a  is turned off when the right ear is brought up against the elastic body unit  4863   b . The inverse occurs when the left ear is brought up against the elastic body unit  4863   a.    
     The one-sided on mode further incorporates the function of the environment-noise microphone  4638 ; when the environmental noise detected by the environment-noise microphone  4638  is at or above a predetermined amount, one of either the switch  4824   a  or the switch  4826   a  is turned on and the other is turned off on the basis of the state detected by the acceleration sensor  49 . In circumstances determined to be silent by the controller  39  when the noise detected by the environment-noise microphone  4638  is at or below a predetermined amount, both the switch  4824   a  and the switch  4826   a  are turned on by a command from the controller  39  irrespective of the state detected by the acceleration sensor  49 , the switch  4836   a  being switched to the state depicted in  FIG. 77 , and the vibrations conducted to the chassis of the mobile telephone  4801  from the elastic body unit  4863   a  and the elastic body unit  4863   b  are thus mutually canceled out. 
       FIG. 78  is a perspective view and cross-sectional views relating to the fifty-second embodiment of  FIG. 77 .  FIG. 78A  is a perspective view in which the mobile telephone  4801  of the fifty-second embodiment is seen from the front surface, and illustrates the manner in which the outer surfaces of the corners of the elastic body units  4863   a ,  4863   b ,  4863   c , and  4863   d  provided as protectors to the four corners of the mobile telephone  4801  are beveled so as to have a smooth, convex shape. As described above, such an outer surface shape of the corner parts of the mobile telephone  4801  prevents the occurrence of slight pain when the elastic member  4863   a  or  4863   b  is brought up against the ear cartilage, and also allows for the corner parts of the mobile telephone  4801  to be suitably fitted to the cartilage around the entrance part of the external auditory meatus inside the auricle, permitting comfortable listening by cartilage conduction. The occlusion of the entrance part of the external auditory meatus by the beveled corner parts produces the earplug bone conduction effect, which intensifies the audio signal from the mobile telephone  4801  in the external auditory meatus and also makes it easier to listen to the audio signal in the presence of noise, due to the noise of the external environment being blocked by the occlusion of the entrance part of the external auditory meatus. 
       FIG. 78B  is a cross-sectional view cutting through the mobile telephone  4801  on the B 1 -B 1  cross-sectional plane of  FIG. 78A , on the plane perpendicular to the front view and side view;  FIG. 78C  is a cross-sectional view cutting through the mobile telephone  4801  on the B 2 -B 2  cross-sectional plane illustrated in  FIG. 78A or 78B , on the plane perpendicular to the plan view and the top view. The manner in which the outer surfaces of the corners of the elastic body units  4863   a ,  4863   b ,  4863   c , and  4863   d  are beveled so as to have a smooth, convex shape will be readily understood from either of  FIG. 78B or 78C . As illustrated by the arrow  25   g  in  FIGS. 78B and 78C , the primary vibration direction of the piezoelectric bimorph element  2525   b  is the direction perpendicular to the display surface of the GUI display unit  3405 . Further, as illustrated by the arrow  25   m  in  FIG. 78B , the primary vibration direction of the piezoelectric bimorph element  2525   a  is the direction perpendicular to the display surface of the GUI display unit  3405 . 
     Although each of the switches  4824   a ,  4826   a , and  4836   a  in the fifty-second embodiment are symbolically depicted in  FIG. 77  as mechanical switches, in practice the same are preferably constituted of electrical switches. Also, except in the case of switching between the two-sided always-on mode and the one-sided on mode, the switches in the fifty-second embodiment have been depicted by way of the example of automatically switching on the basis of the results detected by the acceleration sensor  49  and/or the environment-noise microphone  4638 , but the configuration may also permit manual switching as desired, by the operation unit  9 . It is also possible to omit the switches, as appropriate. For example, when the fifty-second embodiment is simplified so as to always be in the connection state depicted in  FIG. 77 , a mobile telephone is obtained in which the generation of air conduction sound from the entire surface of the chassis is substantially eliminated and cartilage conduction occurs when the elastic body unit  4863   a  or the elastic body unit  4863   b  is brought into contact with the ear cartilage. 
     The various features of each embodiment described above are not to be restricted to individual respective embodiments, but rather can be substituted or combined with other appropriate embodiments. For example, although the fifty-second embodiment of  FIGS. 77 and 78  employs the piezoelectric bimorph elements as cartilage conduction vibration sources, the cartilage conduction vibration sources may be substituted for other vibrators, such as with the magnetic vibrators in the forty-eighth embodiment of  FIGS. 72 and 73 , the fiftieth embodiment of  FIG. 75 , or the fifty-first embodiment of  FIG. 76 . 
       FIG. 79  is a graph illustrating an example of measurement data of the mobile telephone configured on the basis of the forty-sixth embodiment of  FIG. 69 . In the graph of  FIG. 79 , the mobile telephone  4201  of the forty-sixth embodiment (in which configuration the vibration from the vibration source inside the outer wall is transmitted to the surface of the outer wall) is used to illustrate, in relation to the frequency, the sound pressure within the external auditory meatus 1 cm from the entrance part of the external auditory meatus when, without contact with the auricular helix, the surface of the outer wall of the corner parts of the mobile telephone  4201  is brought into contact with at least a part of the ear cartilage around the entrance part of the external auditory meatus, according to  FIGS. 2A and 2B , which have been used to describe the first embodiment. In the graph, the vertical axis is the sound pressure (in dBSPLs), and the horizontal axis is the frequency on a logarithmic scale (in Hz). In terms of the contact pressure relationship between the surface of the outer wall of the corner parts of the mobile telephone  4201  and the cartilage around the entrance part of the external auditory meatus, the graph uses a solid line to illustrate the sound pressure during a non-contact state, a short-dashed line to illustrate the sound pressure in a state of slight contact (10 grams of contact pressure), a single-dotted line to illustrate the sound pressure in a state in which the mobile  4201  is being used normally (250 grams of contact pressure), and a double-dotted line to illustrate the sound pressure in a state in which the external auditory meatus is occluded by increased contact pressure (500 grams of contact pressure). As illustrated, the sound pressure increases from the non-contact state due to contact of 10 grams of contact pressure and increases further due to the contact pressure increasing to 250 grams; the sound pressure increases even more when the contact pressure is increased further from such a state to 500 grams. 
     It will be readily understood from the graph of  FIG. 79  that when the surface of the outer wall of the mobile telephone  4201 , which has the vibration source arranged inward from the surface of the outer wall and is configured such that the vibration of the vibration source is transmitted to the surface of the outer wall, is brought into contact with at least a part of the ear cartilage around the entrance part of the external auditory meatus without making contact with the auricular helix, the sound pressure in the external auditory meatus about 1 cm from the entrance part of the external auditory meatus has an increase of at least 10 dB in the main frequency range of speech (500 Hz to 2,300 Hz), compared to the non-contact state (to be contrasted with the non-contact state illustrated by the solid line and the state in which the mobile telephone  4201  is being used normally, illustrated by the single-dotted line). 
     It will also be readily understood from the graph of  FIG. 79  that when the surface of the outer wall of the mobile telephone  4201  is brought into contact with at least a part of the ear cartilage around the entrance part of the external auditory meatus without making contact with the auricular helix, the sound pressure in the external auditory meatus about 1 cm from the entrance part of the external auditory meatus has an at least 5 dB change in the main frequency range of speech (500 Hz to 2,500 Hz) according to the change in contact pressure (to be contrasted with the slight contact state illustrated by the short-dashed line and the contact state in the state in which the mobile telephone  4201  is being used normally, illustrated by the single-dotted line). 
     It will further be readily understood from the graph of  FIG. 79  that when the entrance part of the external auditory meatus is occluded by the surface of the outer wall of the mobile telephone  4201  being brought into contact with at least a part of the ear cartilage around the entrance part of the external auditory meatus without making contact with the auricular helix (for example, when the surface of the outer wall of the mobile telephone  4201  is strongly pressed against the outside of the tragus, thus folding the tragus over and occluding the external auditory meatus), the sound pressure in the external auditory meatus about 1 cm from the entrance part of the external auditory meatus has an increase of at least 20 dB in the main frequency range of speech (300 Hz to 1,800 Hz) compared to the non-contact state (to be contrasted with the non-contact state illustrated by the solid line and the state in which the external auditory meatus is occluded, illustrated by the double-dotted line). 
     The measurements in  FIG. 79  are all in a state in which the output of the vibration source does not change. The measurements in  FIG. 79  for the state where the surface of the outer wall is brought into contact with at least a part of the ear cartilage around the external auditory meatus without making contact with the auricular helix are performed in a state where the surface of the outer wall was in contact from the outside of the tragus. The measurements in  FIG. 79  made in a state of the external auditory meatus being occluded were performed by creating a state where the external auditory meatus was occluded by the tragus being folded due to being more strongly pressed against from the outside, as described above. 
     As described above, the measurements in  FIG. 79  were performed in a state where the surface at the corner parts of the outer wall in the mobile telephone  4201  of the forty-sixth embodiment illustrated in  FIG. 69  was brought into contact with the outside of the tragus, but the corner parts of the forty-sixth embodiment serve as the elastic body units  4263   a ,  4263   b  acting as protectors, and are constituted of a material different from the other portions of the outer wall. The vibration source is supported on the inner surface of the corner parts of the outer wall constituted of the elastic body units  4263   a ,  4263   b . The corner parts of the outer wall of the mobile telephone  4201  are susceptible to impact from the outside, and are firmly bonded to prevent the occurrence of relative deviation between the outer wall and the other portions even in a case of being constituted of the elastic body units  4263   a ,  4263   b.    
     The measurement graph of  FIG. 79  is merely an example; upon further scrutiny, there are individual differences. Also, the measurement graph of  FIG. 79  was measured in a state where the surface of the outer wall was brought into contact only with a small surface area of the outside of the tragus, for the sake of simplifying and standardizing the phenomenon. However, an increase in sound pressure due to contact also relies on the area of contact with the cartilage, and in a case where the surface of the outer wall is brought into contact with the ear cartilage around the entrance part of the external auditory meatus without making contact with the auricular helix, the increase in sound pressure is elevated further when there is contact with a portion of the cartilage wider than around the entrance part of the external auditory meatus. In consideration of the facts above, the values illustrated in the measurement graph of  FIG. 79  have a certain universality in illustrating the configuration of the mobile telephone  4201 , and can be reproduced by a non-specific number of test subjects. Further, the measurement graph of  FIG. 79  was achieved by the tragus being pressed from the outside when the entrance part of the external auditory meatus is occluded, thus increasing the contact pressure and folding the tragus over, but similar results are also obtained in a case where the corner parts of the mobile telephone  4201  are pressed on the entrance part of the external auditory meatus, which is then occluded. The measurements in  FIG. 79  were measured by the vibration source being held on the inside of the corner parts of the outer wall, as in the mobile telephone  4201  of the forty-sixth embodiment of  FIG. 69 , but there is no limitation thereto, and the measurements are also reproducible in other embodiments as well. For example, [the measurements] are also reproducible with a configuration in which the vibration source is held on the interior of the elastic body units  4363   a ,  4363   b  serving as protectors, as illustrated in  FIG. 72  (for example, an embedded configuration). 
     In other words, the measurement graph of  FIG. 79  suffices to explain the characteristic of the mobile telephone of the present invention, in that when the surface of the outer wall of the mobile telephone, which has the vibration source arranged inward from the surface of the outer wall and is configured such that the vibration of the vibration source is transmitted to the surface of the outer wall, is brought into contact with at least a part of the ear cartilage around the entrance part of the external auditory meatus without making contact with the auricular helix, the sound pressure inside the external auditory meatus about 1 cm from the entrance part of the external auditory meatus has an at least 10 dB increase in at least a part (for example, 1,000 Hz) of the main frequency range of speech (500 Hz to 2,300 Hz), compared to the non-contact state. 
     The graph in  FIG. 79  also suffices to explain the characteristic of the mobile telephone of the present invention, in that when the surface of the outer wall of the mobile telephone is brought into contact with at least a part of the ear cartilage around the entrance part of the external auditory meatus without making contact with the auricular helix, the sound pressure inside the external auditory meatus about 1 cm from the entrance part of the external auditory meatus has an at least 5 dB increase in at least a part (for example, 1,000 Hz) of the main frequency range of speech (500 Hz to 2,500 Hz) due to the increase in contact pressure. 
     The graph in  FIG. 79  further suffices to explain the characteristic of the mobile telephone of the present invention, in that when the entrance part of the external auditory meatus is occluded by the surface of the outer wall of the mobile telephone  4201  being brought into contact with at least a part of the ear cartilage around the entrance part of the external auditory meatus without making contact with the auricular helix, the sound pressure in the external auditory meatus about 1 cm from the entrance part of the external auditory meatus has an increase of at least 20 dB in at least a part (for example, 1,000 Hz) of the main frequency range of speech (300 Hz to 1,800 Hz) compared to the non-contact state. 
     The mobile telephone of the present invention as confirmed by the measurements in the graph of  FIG. 79  is significant in the following manner. Namely, the present invention provides a mobile telephone having a vibration source arranged inward from the surface of an outer wall, and volume adjustment means, the vibration of the vibration source being transmitted to the surface of the outer wall, and sound being listened to by bringing the surface of the outer wall into contact with at least a part of the ear cartilage around the entrance part of the external auditory meatus without making contact with the auricular helix; the features thereof are defined as follows. Namely, in a room where the noise level (the A-weighted sound pressure level) is 45 dB or less, [the mobile telephone] being brought into proximity with the entrance part of the external auditory meatus and the surface of the outer wall being arranged so as to not be in contact, the volume is minimized and pure sound at 1,000 Hz is generated from the vibration source. In addition, narrow-band noise at 1,000 Hz (⅓ octave-band noise) at a marginal level where the pure sound at 1,000 Hz is masked and cannot be heard is generated from a loudspeaker at a position separated from the entrance part of the external auditory meatus by 1 m. This can be confirmed by sequentially increasing narrow-band noise at 1,000 Hz and determining the magnitude at which pure sound at 1,000 Hz is masked and can no longer be heard. The narrow-band noise at 1,000 Hz is subsequently increased by 10 dB from the marginal level, but according to the mobile telephone of the present invention, bringing the surface of the outer wall into contact with at least a part of the ear cartilage around the entrance part of the external auditory meatus without making contact with the auricular helix makes it possible to listen to pure sound at 1,000 Hz without the need to adjust or change the volume adjusting means. 
     When the narrow-band noise at 1,000 Hz is further increased by 20 dB from the marginal level as determined above, according to the mobile telephone of the present invention, bringing the surface of the outer wall into contact with at least a part of the ear cartilage around the entrance part of the external auditory meatus without making contact with the auricular helix makes it possible to listen to pure sound at 1,000 Hz without the need to adjust or change the volume adjusting means. 
       FIG. 80  is a side view and a cross-sectional view of an ear, intended to illustrate the relationship between the detailed structure of the ear and the mobile telephone of the present invention.  FIG. 80A  is a side view of the left ear  30 , where a position  4201   a  shown with a single-dotted line depicts the state where the corner part of the mobile telephone  4201  is brought into contact with the outside of the tragus. The position  4201   a  corresponds to the state in which the measurements of  FIG. 79  were performed. Meanwhile, a position  4201   b  shown by the double-dotted line is a depiction of the state where the corner part of the mobile telephone  4201  is brought into contact with a portion of cartilage wider than that around the entrance part of the external auditory meatus. At the position  4201   b , an increase in sound pressure greater than what is illustrated in  FIG. 79  can be achieved through the contact with the ear cartilage. 
       FIG. 80B  is a cross-sectional view of the right ear  28 , and depicts the manner in which the vibration of the vibration source generated from the corner part of the mobile telephone  4201  is conducted to the tympanic membrane  28   a . The mobile telephone  4201  in the state in  FIG. 80B  has been brought into contact with a portion of cartilage wider than that around the entrance part of the external auditory meatus, according to the position  4201   b  in  FIG. 80A  (though it may not be evident from the portion of the cross-sectional view alone, the entrance part of the external auditory meatus is not occluded in such a state). A vibration  28   b  generated from the corner part of the mobile telephone  4201  is conducted to the cartilage around the entrance part of the external auditory meatus from the portion of contact, and air conduction sound is subsequently generated in the external auditory meatus  28   c  from the cartilage part external auditory meatus surface. The air conduction sound then proceeds through the inside of the external auditory meatus  28   c  and reaches the tympanic membrane  28   a . Direct air conduction  28   d  is also generated from the corner part of the mobile telephone  4201 , and naturally also proceeds through the inside of the external auditory meatus  28   c  and reaches the tympanic membrane  28   a . In the state where the mobile telephone  4201  is not in contact with the cartilage, solely the direct air conduction  28  reaches the tympanic membrane  28   a.    
     An additional description shall now be provided for the frequency characteristics of the piezoelectric bimorph element  2525  used in the forty-sixth embodiment of  FIG. 69  and elsewhere. The frequency characteristics of the piezoelectric bimorph element  2525  used in embodiments of the present invention in regard to the generation of direct air conduction are not flat; rather, the generation of air conduction at frequencies below substantially approximately 1 kHz is correspondingly less than at frequencies above the boundary. Such a frequency characteristic in the piezoelectric bimorph element  2525  in regard to the generation of direct air conduction is ideally matched to the frequency characteristic in a case where there is air conduction sound from the piezoelectric bimorph element  2525  in the external auditory meatus directly via the cartilage. Namely, the sound pressure in the external auditory meatus according to the frequency characteristics in air conduction sound through cartilage conduction is greater in frequencies below about 1 kHz than frequencies that are higher than this boundary. Therefore, in a case involving the use of the piezoelectric bimorph element  2525  of the frequency characteristic described above for the generation of direct air conduction, the fact that the two are complementary results in the frequency characteristic of sound reaching the tympanic membrane being approximately flat. Thus, the cartilage conduction vibration source used in the present invention exhibits a frequency characteristic for the generation of air conduction sound that trends inversely with respect to the frequency characteristic in cartilage conduction. 
       FIG. 79 , which is the measurement data from the forty-sixth embodiment of  FIG. 69 , provides a specific description of such facts. In the graph of  FIG. 79 , sound pressure is viewed by applying a sine wave with a varying frequency at the same voltage to the piezoelectric bimorph element  2525  having the structure illustrated in  FIG. 69 , wherefore the sound pressure in non-contact illustrated by the solid line in the graph of  FIG. 79  substantially exhibits the frequency characteristic for generating air conduction sound generated from the piezoelectric bimorph element  2525 . In other words, as is clear from the solid line in the graph of  FIG. 79 , the frequency characteristic for generating air conduction sound by the piezoelectric bimorph element  2525  is not flat, but rather, when there is a focus on a band between, for example, 100 Hz and 4 kHz, then the comparative sound pressure is low primarily in the low-frequency band (for example, 200 Hz to 1.5 kHz), and the sound pressure is high primarily in the high-frequency band (for example, 1.5 kHz to 4 kHz) (the sound pressure measured in  FIG. 79  is that in the external auditory meatus at about 1 cm from the entrance part of the external auditory meatus, and therefore the influence of the effect of unoccluded ear gain in increasing sound pressure is observed between 2.5 kHz and 3.5 kHz, but it is clear that the high-frequency band has a relatively higher sound pressure than the low-frequency band even when interpreted with this portion subtracted). In this manner, viewed from  FIG. 79  as well, the frequency characteristic of the piezoelectric bimorph element  2525  used in the forty-sixth embodiment of  FIG. 69  and elsewhere is not flat, but rather the generated air conduction sound at low frequencies will be readily understood to be relatively less than that at high frequencies, the boundary being substantially at about 1 kHz. 
     Next, in the graph of the normal state of contact 250 g shown in  FIG. 79  with a single-dotted line, a marked increase in sound pressure compared to the state of non-contact is observed beginning at a few hundred Hz, closer to the lower-frequency region than to 1 kHz; the increase persists until at least about 2.5 kHz. Accordingly, the frequency characteristic of sound measured in the external auditory meatus for the piezoelectric bimorph element  2525 , which is the same vibration source, exhibits a clear difference between direct air conduction and air conduction through cartilage conduction (that is, air conduction through cartilage conduction has a large increase in sound pressure, particularly at a few hundred Hz to 2.5 kHz, compared to direct air conduction). As a result, as illustrated by the graph of the normal state of contact 250 g shown in  FIG. 79  by the single-dotted line, as regards the sound pressure in the external auditory meatus in the case of air conduction through cartilage conduction, the frequency characteristic of the sound that reaches the tympanic membrane as a result is closer to being flat than in the case of direct air conduction illustrated by the solid line. 
     Additionally, a state of external auditory meatus occlusion 500 g illustrated by  FIG. 79  with a double-dotted line has a further pronounced increase in sound pressure between a few hundred Hz to 1 kHz, due to the earplug bone conduction effect, and the piezoelectric bimorph element  2525 , which is the same vibration source, exhibits disparate frequency characteristic clearly different from both the state of normal contact 250 g and the state of non-contact. However, because unoccluded ear gain ceases to be present in the state of external auditory meatus occlusion 500 g illustrated with the double-dotted line, presumably there appears a result such that the effect from the peak sound pressure at 2.5 kHz to 3.5 kHz observed in the state of open external auditory meatus has disappeared. 
     Fifty-Third Embodiment 
       FIG. 81  is a block diagram of a fifty-third embodiment according to an aspect of the present invention. The fifty-third embodiment, similarly with respect to the twenty-fifth embodiment of  FIG. 38 , is configured as 3D television viewing eyeglasses  2381  by which stereo audio information can be experienced, and forms a 3D television viewing system together with a 3D television  2301 . Also similarly with respect to the twenty-fifth embodiment, the vibration of a right-ear cartilage-conduction vibration unit  2324  arranged at a right temple unit  2382  is transmitted to the outer side of the cartilage of the base of the right ear via a contact unit  2363 , and the vibration of a left-ear cartilage-conduction vibration unit  2326  arranged at a left temple unit  2384  is transmitted to the outer side of the cartilage of the base of the left ear via a contact unit  2364 . The fifty-third embodiment has much in common with the twenty-fifth embodiment, and shared portions have therefore been given like reference numerals, a description thereof having been omitted unless there is a particular need. Further, although a depiction in  FIG. 81  has been omitted, the internal configuration of the 3D television  2301  is the same as is illustrated in  FIG. 38 . 
     The fifty-third embodiment of  FIG. 81 , similarly with respect to the twenty-fifth embodiment of  FIG. 38 , uses the piezoelectric bimorph element  2525  having a similar structure to that of the forty-sixth embodiment of  FIG. 69 , as the right-ear cartilage-conduction vibration unit  2324  and the left-ear cartilage-conduction vibration unit  2326 . In other words, the right-ear cartilage-conduction vibration unit  2324  and the left-ear cartilage-conduction vibration unit  2326  exhibit a frequency characteristic for the generation of direct air conduction that trends inversely with regard to the frequency characteristic in cartilage conduction, the generation of air conduction at frequencies below substantially approximately 1 kHz being correspondingly less than at frequencies above the boundary. Specifically, the right-ear cartilage-conduction vibration unit  2324  and the left-ear cartilage-conduction vibration unit  2326  employed in the fifty-third embodiment of  FIG. 81  have a difference of 5 dB or greater between the mean air conduction output from 500 Hz to 1 kHz and the mean air conduction output from 1 kHz to 2.5 kHz, compared to an average, typical speaker designed in consideration of air conduction, and exhibit a frequency characteristic that would be undesirable for a typical speaker. 
     A point of difference in the fifty-third embodiment of  FIG. 81  from the twenty-fifth embodiment of  FIG. 38  lies in that the driving of the above-described right-ear cartilage-conduction vibration unit  2324  and left-ear cartilage-conduction vibration unit  2326  is performed via a frequency characteristic correction unit  4936 . The frequency characteristic correction unit  4936  is provided with a cartilage conduction equalizer  4938  for correcting the frequency characteristic of the sound pressure serving as air conduction sound in the external auditory meatus so as to approach flatness, in consideration of the frequency characteristic specific to cartilage conduction. The cartilage conduction equalizer  4938  fundamentally corrects the frequency characteristic of the drive signals to the right-ear cartilage-conduction vibration unit  2324  and to the left-ear cartilage-conduction vibration unit  2326  equally, but it is also possible to utilize separately corrections for the variations between the right-ear cartilage-conduction vibration unit  2324  and the left-ear cartilage-conduction vibration unit  2326 . The frequency characteristic correction unit  4936  is further provided with a cartilage conduction low-pass filter  4940  for trimming higher frequencies (e.g., trimming 10 kHz and higher). The cartilage conduction low-pass filter  4940  is intended to prevent the unpleasant outward divergence of air conduction, because the right-ear cartilage-conduction vibration unit  2324  and the left-ear cartilage-conduction vibration unit  2326  in the fifty-third embodiment are shaped such that the ear is not covered. The characteristics of the low-pass filter have been determined in consideration that the frequency region advantageous for cartilage conduction (for example, 10 kHz and lower) not be trimmed. In terms of acoustics, it is disadvantageous for an audio device to trim out the audible range (for example, 10 kHz to 20 kHz) and the frequency band thereabove, and the configuration is therefore such that the functions of the cartilage conduction low-pass filter  4940  can be turned off manually in an environment where consideration need not be given to the unpleasant outward divergence of air conduction. 
     Fifty-Fourth Embodiment 
       FIG. 82  is a block diagram of a fifty-fourth embodiment according to an aspect of the present invention. The fifty-fourth embodiment, similarly with respect to the fourth embodiment of  FIG. 8 , is configured as a mobile telephone  5001 . The fifty-fourth embodiment has much in common with the fourth embodiment, and shared portions have therefore been given like reference numerals, a description thereof having been omitted unless there is a need. The fifty-fourth embodiment of  FIG. 82 , similarly with respect to the fifty-third embodiment of  FIG. 81 , uses the piezoelectric bimorph element  2525  having a similar structure to that of the forty-sixth embodiment of  FIG. 69 , serving as the vibration source of the cartilage conduction vibration unit  228 . In other words, the vibration source of the cartilage conduction vibration unit  228  exhibits a frequency characteristic for the generation of direct air conduction that trends inversely with regard to the frequency characteristic in cartilage conduction, the generation of air conduction at frequencies below substantially approximately 1 kHz being correspondingly less than at frequencies above the boundary. Specifically, as with the fifty-second embodiment, the piezoelectric bimorph element employed in the fifty-fourth embodiment of  FIG. 82  has a difference of 5 dB or greater between the mean air conduction output from 500 Hz to 1 kHz and the mean air conduction output from 1 kHz to 2.5 kHz, compared to an average, typical speaker designed with the expectation of air conduction, and exhibits a frequency characteristic that would be undesirable for a typical speaker. 
     A point of difference in the fifty-fourth embodiment of  FIG. 82  from the fourth embodiment of  FIG. 8  lies in the manner in which the above-described piezoelectric bimorph element of the vibration source of the cartilage conduction vibration unit  228  is driven, being performed via a cartilage conduction low-pass filter  5040  for trimming higher frequencies (e.g., trimming 2.5 kHz and higher) and via a cartilage conduction equalizer  5038 . The cartilage conduction equalizer  5038 , similarly with respect to the fifty-third embodiment, corrects the frequency characteristic of the sound pressure serving as air conduction sound in the external auditory meatus so as to approach flatness, in consideration of the frequency characteristic specific to cartilage conduction. An audio signal passed via the cartilage conduction equalizer  5038  will have undergone a frequency characteristic correction in consideration of the frequency characteristic specific to cartilage conduction, and therefore has a different frequency characteristic from an audio signal to the speaker  51  for a videoconferencing function, in which the generation of direct air conduction is presumed. 
     The cartilage conduction equalizer  5038  of the fifty-fourth embodiment, upon detection by the pressure sensor  242  of the state where the ear hole is blocked and the earplug bone conduction effect occurs, automatically switches the frequency characteristic to be corrected from the frequency characteristic used in the normal state of contact to the frequency characteristic used in the state where the earplug bone conduction effect is generated. The difference in correction for the frequency correction to which a switch is thereupon made corresponds to, for example, the difference between the single-dotted line (normal contact 250 g) and double-dotted line (external auditory meatus occlusion 500 g) in  FIG. 79 . Specifically, the frequency characteristic is corrected so as to prevent an over-emphasis of the lower sound region when the earplug bone conduction effect occurs and so as to compensate for the loss of unoccluded ear gain due to the occlusion of the external auditory meatus, thus attenuating the change in acoustics between the presence and absence of the earplug bone conduction effect. 
     The cartilage conduction low-pass filter  5040  in the fifty-fourth embodiment has the objectives of preventing sound in the band that can be heard by ear from leaking out and of protecting privacy, and is particularly useful at times of silence. The characteristics of the cartilage conduction low-pass filter  5040  have been determined in consideration that the frequency band at which contact with the ear cartilage has a pronounced effect in increasing sound pressure (for example, 2.5 kHz and lower) not be trimmed. The audio of the mobile telephone, from the start, is trimmed at 3 kHz or higher, but the band from a few hundred Hz to about 2.5 kHz, where the effect of cartilage conduction in increasing sound pressure is high even without unoccluded ear gain, is actively used; frequencies at 2.5 kHz and higher, other than the band at which the effect specific to cartilage conduction emerges, are trimmed, whereby the aforementioned privacy protection can reasonably be fulfilled. As noted above, the effects of the cartilage conduction low-pass filter  5040  are particularly important at times of silence, and therefore, in a preferred configuration, can be turned on and off manually, or can be automatically turned on only in times of silence by the environment-noise microphone  4638  provided in the fiftieth embodiment of  FIG. 75  or a similar element. In the configuration in which the cartilage conduction low-pass filter  5040  can be turned on and off manually, there is the expectation that noise is louder when the cartilage conduction equalizer  5038  uses the frequency characteristic of the state where the earplug bond conduction effect occurs; therefore, the cartilage conduction low-pass filter  5040  is configured so as to be forcibly turned off when turned on manually. 
     The implementation of the features of the present invention illustrated by the embodiments above is not to be limited to the respective embodiments above. For example, the fifty-third embodiment and fifty-fourth embodiment above combine the cartilage conduction vibration source and cartilage conduction equalizer for imparting the generation of air conduction sound having a frequency characteristic that differs from the normal frequency characteristic for generating air conduction in that the final frequency characteristic of air conduction sound having passed through cartilage conduction approaches flatness; however, it is also possible to omit either one thereof. For example, the cartilage conduction equalizer can be omitted when the cartilage conduction vibration source used is well suited for the frequency characteristic of cartilage conduction. Conversely, another possible configuration is one where the cartilage conduction vibration source employed has a frequency characteristic for imparting the generation of air conduction sound according to a normal air conduction speaker, and the function adapted to bring the final frequency characteristic of air conduction having passed through cartilage conduction closer to flatness is concentrated in the cartilage conduction equalizer. 
     Fifty-Fifth Embodiment 
       FIG. 83  is a perspective view and a cross-sectional view relating to a fifty-fifth embodiment according to an aspect of the present invention, which is configured as a mobile telephone  5101 . The fifty-fifth embodiment is consistent with the forty-sixth embodiment illustrated in  FIG. 69 , except for the holding structure of the cartilage conduction vibration source  2525 , which is constituted of a piezoelectric bimorph element, and except for the addition of a T-coil (described later), and therefore shared portions have been assigned like reference numerals and a description thereof has been omitted unless there is a need. 
     First, the holding structure for the cartilage conduction vibration source  2525  in the fifty-fifth embodiment shall now be described. As is clear from the perspective view in  FIG. 83A , the left and right corner parts of the mobile telephone  5101  are provided with cartilage conduction units  5124  and  5126  composed of a hard material. Examples of suitable materials for the cartilage conduction units  5124  and  5126  include an ABS resin, fiber-reinforced plastic, or high-toughness fine ceramic. Elastic bodies  5165   b  and  5165   a  made of a vinyl-based, urethane-based, or other type of material are interposed between the cartilage conduction units  5124  and  5126  and the chassis of the mobile telephone  5101 , and function as a vibration isolation material and as a cushioning material. 
     As is also clear from  FIGS. 83B and 83C , the cartilage conduction units  5124  and  5126  are structured to hold the piezoelectric bimorph element  2525  at the inside thereof. The piezoelectric bimorph element  2525  is also structured to be held at the chassis of the mobile telephone  5101 , without making direct contact, by the interposed elastic bodies  5165   b  and  5165   a . The vibration energy of the piezoelectric bimorph element  2525  is thereby concentrated on the cartilage conduction units  5124  and  5126 , and also thereby prevented from being dispersed to the chassis of the mobile telephone  5101 . 
     Further, as illustrated in  FIG. 83A  by the short-dashed line, a T-coil  5121  is arranged inside the center of the upper part of the mobile telephone  5101  in the fifty-fifth embodiment. The T-coil  5121  is intended to transmit audio information by electromagnetic induction to a hearing aid provided with a corresponding T-coil. A description of the relationship between the manner in which the T-coil transmits audio information and the manner in which cartilage conduction transmits audio information will be provided later. 
       FIG. 84  is a block diagram of the fifty-fifth embodiment of  FIG. 83 , in which like portions have been assigned like reference numerals to those in  FIG. 83  and a description thereof has been omitted. The configuration of the block diagram of  FIG. 84  has much in common with the block diagram of the fifty-fourth embodiment in  FIG. 82 . Since these elements can be referenced, shared parts of the configuration have been given like reference numerals and a description thereof has been omitted. 
     The fifty-fifth embodiment includes the T-coil  5121 , as has already been described, and in a case where the user of the mobile telephone  5101  is wearing a hearing aid provided with a T-coil, audio information can be transmitted to the hearing aid by electromagnetic induction through the T-coil  5121 . The T-coil function of the hearing aid provided with a T-coil can be turned on and off, the configuration being such that a selection can be made to turn the microphone of the hearing aid on or off in a case where the T-coil has been turned on. Correspondingly, a switch  5121   a  of the mobile telephone  5101  of the fifty-fifth embodiment can be turned on or off in response to an operation of the operation unit  9  and a selection can be made as to whether or not to cause the T-coil  5121  to function. In a case where a selection is made to turn the T-coil  5121  on, there is provided a switch  5121   b  for forcibly turning off, in conjunction therewith, the cartilage conduction vibration unit  228 , which includes the piezoelectric bimorph element  2525 . 
     As has already been described, in the state where the ear is plugged as well, cartilage conduction generates air conduction sound within the external auditory meatus along with the earplug bone conduction effect. As a result, in a case where the entrance to the external auditory meatus is blocked by the hearing aid, sound can still be heard without the T-coil  5121  being turned on, due to cartilage conduction, the vibration source of which is the piezoelectric bimorph element  2525 . The cartilage conduction occurs fundamentally due to the cartilage conduction unit  5124  or  5126  being brought into contact with the ear cartilage, but bringing the cartilage conduction unit  5124  or  5126  into contact with the hearing aid also makes cartilage conduction possible due to the generation of air conduction sound inside the external auditory meatus due to the vibration thereof being conducted to the ear cartilage around the hearing aid. Also, depending on the manner in which the cartilage conduction unit  5124  or  5126  is held thereagainst, contact can be made with both the ear cartilage and the hearing aid, air conduction sound being generated inside the external auditory meatus in such a state of concurrence. In this manner, the mobile telephone  5101  of the present invention can be utilized by the user of the hearing aid even in the state where the T-coil  5121  has been turned off. 
     The switch  5121   b  is intended to prevent the simultaneous occurrence of the above-described cartilage conduction when the switch  5121   a  has been turned on to cause the T-coil  5121  to function, and the occurrence of any awkwardness compared to sound normally listened to with the T-coil, and is also intended to prevent the unnecessary consumption of power due to cartilage conduction during the operation of the T-coil  5121 . To prevent accidental confusion where cartilage conduction is turned off when the T-coil  5121  is turned on by a mistaken operation, the configuration is such that typically a menu to turn the T-coil  5121  on will not appear in the operation menu of the operation unit  9  displayed on the large-screen display unit  205 ; in a preferred configuration, the T-coil  5121  will not turn on unless a predetermined procedure is followed to intentionally operate the operation unit  9 . 
       FIG. 85  is a side view for describing the manner in which the vibration energy is distributed in the mobile telephone  5101  in the fifty-fifth embodiment described above, and has much in common with  FIG. 2 ; shared portions have therefore been given like reference numerals and a description thereof has been omitted. As illustrated in  FIG. 83 , the cartilage conduction units  5124  and  5126 , which directly hold the piezoelectric bimorph element  2525 , are held at the chassis of the mobile telephone  5101  by the interposed elastic bodies  5165   b  and  5165   a . The vibration of the piezoelectric bimorph element  2525  is thereby effectively conducted to the ear cartilage from the cartilage conduction units  5124  and  5126 , and moreover the vibration is less prone to be conveyed to the chassis of the mobile telephone  5101 , because the piezoelectric bimorph element  2525  is not in direct contact therewith. In other words, the structure is such that the vibration energy of the piezoelectric bimorph element  2525  is concentrated on the cartilage conduction units  5124  and  5126 , and is not dispersed to the chassis of the mobile telephone  5101 . 
     A specific description by way of  FIG. 85  shall now be provided. Because the vibration energy is concentrated on the cartilage conduction units  5124  and  5126 , the amplitude and acceleration of vibration are greatest at positions (1) and (2) on the surface of the chassis of the mobile telephone  5101  (see the encircled numbers 1, 2 in  FIG. 85 ), and a position (3) between the cartilage conduction units  5124  and  5126  on the chassis of the mobile telephone  5101  (see the encircled number 3 in  FIG. 85 ) has somewhat less amplitude and acceleration of vibration. Also, a position (4) and a position (5) (see the encircled numbers 4, 5 in  FIG. 85 ) are separated from the positions (1) and (2) in that order, and have correspondingly decreasing amplitude and acceleration of vibration on the surface of the chassis of the mobile telephone  5101 . For example, the amplitude and acceleration of vibration on the surface of the chassis of the mobile telephone  5101  at the position (5), which is separated from each of the positions (1) and (2) by 5 cm or more, become ¼ or less (25% or less) of the amplitude and acceleration of vibration on the surface at the cartilage conduction units  5124  and  5126 .  FIG. 85A  illustrates the state where the mobile telephone  5101  in which vibration is thus distributed is held up to the right ear  28  and suitable cartilage conduction is obtained, and  FIG. 85B  illustrates the state where the mobile telephone  5101  is held up to the left ear  30  and similarly suitable cartilage conduction is obtained. 
     The feature by which the vibration energy for the cartilage conduction described above is concentrated at the parts of expected contact with the ear cartilage at the entrance part of the external auditory meatus is not limited to the fifty-fifth embodiment illustrated in  FIGS. 83 to 85 , and also appears in several other embodiments that have already been described. For example, the first to third, eleventh to fourteenth, twenty-ninth to thirty-third, thirty-fifth, thirty-sixth, forty-second to forty-fourth, forty-sixth to fiftieth, fifty-second, and fifty-fifth embodiments are examples where the vibration acceleration or amplitude of vibration at the parts of expected contact is greater than the vibration acceleration or amplitude of vibration at portions separated from the parts of expected contact, this effect being particularly pronounced in configurations as in the twenty-ninth, thirtieth to thirty-third, forty-second to forty-third, forty-sixth to fiftieth, fifty-second, and fifty-fifth embodiments, as will be described later. For reasons that will be described later, the vibration acceleration or amplitude of vibration decreases monotonically, relative to the parts of expected contact, as the distance from the parts of expected contact increases. 
     The parts of expected contact, at which the vibration energy for cartilage conduction is concentrated in the present invention, do not protrude from the chassis, and are not shaped so as to hinder the use of the mobile telephone. Further, the parts of expected contact are found at positions removed from both the central up-down axis and central left-right axis of the chassis, and are suitably disposed in contact with the ear cartilage at the entrance part of the external auditory meatus. Specifically, the parts of expected contact are found at corner parts or an upper side part or side surface part in the vicinity of the corner parts of the mobile telephone. In other words, the arrangement configuration described above obtains a suitable configuration by which the surface of the outer wall is brought into contact with at least a part of the ear cartilage around the entrance part of the external auditory meatus without making contact with the auricular helix. 
     As described above, in the present invention, the vibration energy can be concentrated at the parts of expected contact with the ear cartilage at the entrance part of the external auditory meatus not only in the fifty-fifth embodiment of  FIGS. 83 to 85  but also in other embodiments. To classify this feature, firstly, the twenty-ninth embodiment, the thirtieth embodiment, the second modification example of the thirty-first embodiment, the thirty-second embodiment, the thirty-third embodiment, and the fifty-fifth embodiment are first examples where elastic bodies create an isolation between the parts of expected contact and the chassis of the mobile telephone, whereby the feature is realized. The twenty-ninth embodiment, the thirtieth embodiment, the thirty-second embodiment, and the thirty-third embodiment are second examples where the primary vibration direction of the piezoelectric bimorph element is avoided and the same is supported on the chassis of the mobile telephone, whereby the vibration energy is concentrated at the parts of expected contact. The thirtieth embodiment, the thirty-first embodiment, and the forty-seventh embodiment are third examples where there is a reduced surface area of contact between the parts of expected contact and the chassis of the mobile telephone supporting the same, whereby the vibration energy is concentrated at the parts of expected contact. The forty-second to forty-fourth embodiment, the forty-sixth embodiment and the modification example thereof, the forty-eighth to fiftieth embodiments, the fifty-second embodiment, and the fifty-fifth embodiment are fourth examples where the holding position of the vibrator is limited to the vicinity of the parts of contact, whereby the vibration energy is concentrated at the parts of expected contact. The forty-sixth embodiment and the modification example thereof, the forty-eighth to fiftieth embodiments, the fifty-second embodiment, and the fifty-fifth embodiment are fifth examples where the parts of expected contact have a different material from that of the chassis of the mobile telephone, whereby the vibration energy is concentrated at the parts of expected contact. However, as is clear from the fact that some embodiments are duplicated in the classifications described above, the features classified as above can in practice be employed in a plurality of combinations. 
     The various features of the present invention described above are not limited to the embodiments described above. For example, as a modification example of the fifty-fifth embodiment, another possible configuration is one where a hole having a greater cross-sectional area than that of the piezoelectric bimorph element  2525  is opened at each of the elastic bodies  5165   b  and  5165   a , the cross-section of which is illustrated by  FIG. 83B , the piezoelectric bimorph element  2525  being held through the holes by the cartilage conduction units  5124  and  5126 . Such a case is structured such that the piezoelectric bimorph element  2525  does not make direct contact with the elastic bodies  5165   b  and  5165   a , and it becomes possible to prevent the vibration energy of the piezoelectric bimorph element  2525  from being dispersed to the chassis of the mobile telephone  5101  via the elastic bodies  5165   b  and  5165   a.    
     The fifty-fifth embodiment described above, similarly with respect to the forty-sixth embodiment illustrated in  FIG. 69 , is structured such that the vibration of both ends of a single piezoelectric bimorph element  2525  is conducted to the left and right cartilage conduction units  5124  and  5126 ; however, the implementation of a feature such as that of the fifty-fifth embodiment is not to be limited thereto. For example, the holding structure of the fifty-fifth embodiment of  FIG. 83  may be applied to the structure in which one side of the piezoelectric bimorph element  2525  is supported by the cantilever structure, as in the forty-second embodiment of  FIG. 65 . Furthermore, in a configuration as in the fifty-second embodiment of  FIG. 77 , where the right ear piezoelectric bimorph element  2525   b  and the left ear piezoelectric bimorph element  2525   a  are employed, the holding structure of the fifty-fifth embodiment of  FIG. 83  may be applied to the manner in which the same are each supported by the cantilever structure. 
     As has already been described, the ability to independently control the right ear and left-ear cartilage-conduction vibration unit s, as in the first to third embodiments in  FIGS. 1 to 7  and the fifty-second embodiment in  FIG. 77 , makes it possible to stop the vibration of the vibration unit, which is not brought into contact with the ear cartilage. In such a case, in the distribution of vibration energy in the case where the vibration of the cartilage conduction unit  5126  is stopped in  FIG. 85A  illustrating the state where the cartilage conduction unit  5124  is held against the right ear  28 , the amplitude and acceleration of vibration are greatest at the position (1); the amplitude and acceleration of vibration subsequently decrease at the position (3), the position (2), the position (4), and the position (5), in this order. By contrast, in the distribution of vibration energy in the case where the vibration of the cartilage conduction unit  5124  is stopped in  FIG. 85B  illustrating the state where the cartilage conduction unit  5126  is held against the left ear  30 , the amplitude and acceleration of vibration are greatest at the position (2); the amplitude and acceleration of vibration subsequently decrease at the position (3), the position (1), the position (4), and the position (5), in this order. 
     Fifty-Sixth Embodiment 
       FIG. 86  is a perspective view and a cross-sectional view relating to a fifty-sixth embodiment according to an aspect of the present invention, which is configured as a mobile telephone  5201 . The fifty-sixth embodiment is consistent with the fifty-fifth embodiment illustrated in  FIG. 83 , except for the holding direction of the cartilage conduction vibration source  2525  constituted of the piezoelectric bimorph element; shared portions have been given like reference numerals, and a description thereof has been omitted unless there is a need. 
     In the fifty-fifth embodiment of  FIG. 83 , the metal sheet  2597  of the cartilage conduction vibration source  2525  is arranged so as to be parallel to the front surface of the mobile telephone  5101 , and the primary vibration direction is oriented orthogonal to the GUI display unit  3405 . By contrast, in the fifty-sixth embodiment of  FIG. 86 , a metal sheet  2599  of a cartilage conduction vibration unit  5225  is arranged so as to be perpendicular to the front surface of the mobile telephone  5201 , as a result of which the primary vibration direction of the cartilage conduction vibration unit  5225  becomes parallel to the GUI display unit  3405 , similarly with respect to the first modification example of the forty-second embodiment illustrated in  FIG. 65C . The configuration of the fifty-sixth embodiment is suitable for usage where, the front surface side of a corner part (the cartilage conduction unit  5124  or  5126 ) of the mobile telephone  5201  being held against the ear cartilage identically with respect to the case illustrated in  FIG. 85 , the top surface side of the corner part is held against the ear cartilage in such a form as to lightly push upward, similarly with respect to the first modification example of the forty-second embodiment. Because the vibration is concentrated on the cartilage conduction unit  5124  or  5126 , sufficient cartilage conduction can be obtained merely by bringing only the front surface side of a corner part (the cartilage conduction unit  5124  or  5126 ) up against the ear cartilage. 
     In the fifty-sixth embodiment of  FIG. 86 , because the primary vibration direction of the cartilage conduction vibration unit  5225  is parallel to the front surface of the mobile telephone  5201  (which includes the GUI display unit  3405 ), there is a smaller vibration component transmitted to the front surface and rear surface, which account for a large surface area of the outer surfaces of the mobile telephone  5201 . As a result, there can be a further reduction in sound leakage due to air conduction sound generated at such portions of the large surface area. 
     The cartilage conduction vibration unit  5225  oriented in the manner described above as in the fifty-sixth embodiment of  FIG. 86  is not limited to the fifty-sixth embodiment, but rather can also be employed in the forty-sixth embodiment of  FIG. 69 , the forty-sixth embodiment of  FIG. 71 , the forty-ninth embodiment of  FIG. 74 , and other embodiments. 
     Fifty-Seventh Embodiment 
       FIG. 87  is a block diagram relating to a fifty-seventh embodiment according to an aspect of the present invention, which is configured as a mobile telephone  5301 . A piezoelectric bimorph element  5325  constituting the cartilage conduction vibration unit in the fifty-seventh embodiment has a drive circuit configured as a power management circuit for supplying, together with a single-chip integrated power management IC  5303 , power to each of the parts of the mobile telephone  5301 . 
     The integrated power management IC  5303  has a power management unit  5353  and supplies different, respectively predetermined power voltages to an RF circuit unit  5322  connected to an analog baseband unit  5313  and an antenna  5345  and coupled to a digital baseband unit  5312 , and to other elements constituting the telephone communication unit, on the basis of the power supply from a battery  5348 . The power management unit  5353  further supplies different, respectively predetermined power voltages to: an application processor  5339  corresponding to the controller  39  or the like illustrated in other embodiments, a camera unit  5317  (depicted as a consolidation of the backside main camera and videoconferencing function in-camera illustrated in other embodiments), a liquid crystal display device  5343  and touch panel  5368  in a display unit  5305 , and other elements. The application processor  5339 , which is linked with a memory  5337  (depicted as a consolidation of a program holding function and a data writing and holding function), controls the entirety of the mobile telephone  5301  and is capable transferring signals with external apparatuses via a memory card  5319  (depicted as a consolidation of a slot and a card) and a USB™ connection terminal  5320 . 
     The power management unit  5353  also supplies different, respectively predetermined power voltages to a controller  5321 , an analog front-end unit  5336 , an amplifier  5341  for a videoconferencing function speaker  5351 , a cartilage conduction acoustic signal processing unit  5338 , a charge pump circuit  5354 , and other elements within the integrated power management IC  5303 . The charge pump circuit  5354  is intended to boost the voltage for the piezoelectric bimorph element  5325 , which requires high voltage. 
     The analog front-end unit  5336  receives an analog audio signal from the application processor  5339 , which is outside the integrated power management IC  5303  and supplies the same to the videoconferencing function speaker  5351  via the amplifier  5341 , also supplying the analog audio signal to an earphone jack  5314  and the cartilage conduction acoustic signal processing unit  5338 . The analog front-end unit  5336  also transmits an analog audio signal picked up from the user by the microphone  5323  to the outside application processor  5339 . 
     The charge pump circuit  5354  operates to boost voltage in cooperation with an exterior attached condenser  5355 , which is connected via exterior attached terminals  5355   a  and  5355   b , and supplies to the amplifier  5340  the voltage needed to drive the piezoelectric bimorph element  5325 . The audio signal from the analog front-end unit  5336  thereby drives the piezoelectric bimorph element  5325  via the cartilage conduction acoustic signal processing unit  5338  and the amplifier  5340 . Examples corresponding to the functions of the cartilage conduction acoustic signal processing unit  5338  include the acoustics adjustment unit  238  and waveform inverter  240  illustrated in the fourth embodiment of  FIG. 8 , the cartilage conduction low-pass filter  5040  and cartilage conduction equalizer  5038  illustrated in the fifty-fourth embodiment of  FIG. 82 , but there is no limitation thereto. 
     The controller  5321  transfers digital control signals with the application processor  5339 , which is outside the integrated power management IC  5303 , and controls the power management unit  5353 . The controller  5321  controls the analog front-end unit  5336  on the basis of a command from the application processor  5339 , and performs such operations as switching between sending the analog audio signal received from the application processor  5339  to the amplifier  5341  or sending the same to the cartilage conduction acoustic signal processing unit  5338 , in order to drive the videoconferencing function speaker  5351 . The analog front-end unit  5336  also performs such processing as preventing the “popping sound” that accompanies the switching from being outputted to the earphone jack  5314  and other elements. 
     The controller  5321  also transfers digital control signals with the application processor  5339 , which is outside the integrated power management IC  5303 , and controls the cartilage conduction acoustic signal processing unit in a manner relating to the acoustics adjustment, waveform inversion, the cartilage conduction low-pass filter, and the cartilage conduction equalizer, among others as exemplified above. 
     Because the fifty-seventh embodiment of  FIG. 87 , as described above, has the drive circuit of the cartilage conduction vibration unit configured as a single-chip integrated IC together with a power management circuit, the cartilage conduction vibration unit can be driven directly, and power voltage can be supplied to the cartilage conduction vibration unit integratedly with the supply of power voltage to the various constituent elements inside the mobile telephone, it being possible to also integrate the control thereof. Also, having the cartilage conduction acoustic signal processing unit for the cartilage conduction vibration unit configured as a single-chip integrated IC together with a power management part further allows for the control of the audio signals of the piezoelectric bimorph element to be integrated. In a case where the piezoelectric bimorph element is employed as the cartilage conduction vibration unit, although high voltage is needed to drive the same, having the drive circuit of the cartilage conduction vibration unit configured as a single-chip integrated IC together with a power management unit, as in the fifty-seventh embodiment of  FIG. 87 , makes it possible to drive the piezoelectric bimorph element without the need to add a separate chip for a boosted-voltage circuit. Having the cartilage conduction acoustic signal processing unit dedicated to driving the cartilage conduction vibration unit configured as a single-chip integrated IC together with a power management part further allows for the control of the audio signals of the piezoelectric bimorph element to be integrated. It is accordingly possible to endow the mobile telephone with a suitable cartilage conduction function merely by inputting an ordinary audio signal to the integrated IC and connecting the cartilage conduction vibration unit to the integrated IC. 
     Further, having the analog-front end unit configured as a single-chip integrated IC together with the power management unit allows for the output of audio signals to be collectively switched and adjusted. Specifically, the transfer of digital control signals between the integrated IC and the application processor, relating to the functions of the overall mobile telephone inclusive of the functions of the cartilage conduction vibration unit, can be integrated with the transfer of analog audio signals between the integrated IC and the application processor. 
     The circuit configuration in which the drive circuit of the cartilage conduction vibration unit is configured as the power management unit and the single-chip integrated IC, as in the fifty-seventh embodiment of  FIG. 87 , can also be applied to the various other embodiments that have already been described. 
     Fifty-Eighth Embodiment 
       FIG. 88  is a perspective view and a cross-sectional view relating to a fifty-eighth embodiment according to an aspect of the present invention, which is configured as a mobile telephone  5401 . The fifty-eighth embodiment is consistent with the fifty-fifth embodiment illustrated in  FIG. 83 , except for a configuration intended as a countermeasure against sound leakage due to air conduction sound (described later), and therefore shared portions have been given like reference numerals and a description thereof has been omitted unless there is a need. 
     In the fifty-eighth embodiment of  FIG. 88 , similarly with respect to the fifty-fifth embodiment illustrated in  FIG. 83 , there is slight vibration conducted to the chassis of the mobile telephone  5401  via the elastic bodies  5165   b  and  5165   a  from the cartilage conduction units  5124  and  5126  composed of a hard material, which hold the cartilage conduction vibration source  2525 . The front surface and rear surface of the mobile telephone  5401 , which account for a large surface area of the outer surfaces thereof, are thereby made to vibrate, and slight sound leakage due to air conduction sound is generated. In the fifty-eighth embodiment of  FIG. 88 , the outer surface of the chassis of the mobile telephone  5401 , except for the portions of the GUI display unit  3405  and the microphone  23 , is covered by an elastic body  5463 , as a countermeasure against such sound leakage. Herein, the elastic body  5463  is bonded so as to be integrated with the chassis of the mobile telephone  5401 . The portion of the GUI display unit  3405  then becomes an opening part so as not to hinder GUI operation. The portion of the microphone  23  is configured as the microphone cover unit  467  having a sponge-like or similar structure that will not hinder the air conduction of audio, similarly with respect to the fifth embodiment of  FIG. 11   
     The elastic body  5463  for covering the outer surface of the chassis of the mobile telephone  5401  is preferably made of the same vinyl-based, urethane-based, or other type of vibration insulation material and cushioning material as the elastic bodies  5165   b  and  5165   a , or such a material similar thereto. The cartilage conduction units  5124  and  5126  composed of a hard material, which hold the cartilage conduction vibration source  2525 , are, in the fifty-eighth embodiment of  FIG. 88 , thereby in contact with the chassis of the mobile telephone  5401  through being included via the elastic bodies  5165   b ,  5165   a  and the elastic body  5463 . The cartilage conduction vibration source  2525  accordingly does not make direct contact with the chassis of the mobile telephone  5401 . 
     Also, because the elastic body  5463  is not an insertable/releasable cover as in the fifth embodiment of  FIG. 11 , but is bonded so as to be integrated with a large portion of the surface area of the surface of the chassis of the mobile telephone  5401 , the vibration of the large portion of the surface area of the surface of the chassis of the mobile telephone  5401  is suppressed by the weight and elasticity thereof in both the interior and exterior directions over the amplitude of vibration, and vibration energy is also absorbed. The surface of the mobile telephone  5401 , which is contact with the air, is also given elasticity. The air conduction sound generated from the surface of the chassis of the mobile telephone  5401 , caused by the vibration of the cartilage conduction vibration source  2525  across the chassis of the mobile telephone  5401 , is thereby attenuated. On the other hand, because the elastic body  5463  has an acoustic impedance approximating that of the ear cartilage, there is favorable cartilage conduction to the ear cartilage from the cartilage conduction units  5124  and  5126 . The manner in which the elastic body  5463  covers the surface of the chassis of the mobile telephone  5401  also functions as a protection for when the mobile telephone  5401  collides with an external unit. 
     Fifty-Ninth Embodiment 
       FIG. 89  is a perspective view and a cross-sectional view relating to a fifty-ninth embodiment according to an aspect of the present invention, which is configured as a mobile telephone  5501 . The fifty-ninth embodiment is consistent with the forty-second embodiment illustrated in  FIG. 65 , except for a configuration intended as a countermeasure against sound leakage due to air conduction sound, and therefore portions shared by cross-sectional views in  FIGS. 89B and 89C  with the cross-sectional views in  FIGS. 65A and 65B  have been assigned like reference numerals, and a description thereof has been omitted unless there is a need. The perspective view of  FIG. 89A  is consistent with the fifty-eighth embodiment of  FIG. 88A , and therefore shared portions have been assigned like reference numerals and a description thereof has been omitted unless there is a need. 
     In the fifty-ninth embodiment of  FIG. 89 , one end of the piezoelectric bimorph element  2525  is held in a hole in a support structure  3800   a  for holding the cartilage conduction vibration source  2525 , the support structure  3800   a  extending inward from a side surface  3807  and top surface  3807   a  of the mobile telephone  5501 . The vibration of the cartilage conduction vibration source  2525  is therefore conducted to the chassis of the mobile telephone  5501  via the side surface  3807  and top surface  3807   a  of the mobile telephone  5501  from the support structure  3800   a , and the front surface and rear surface of the mobile telephone  5501 , which account for a large surface area of the outer surfaces thereof, are therefore made to vibrate. There is also greater sound leakage due to the air conduction sound generated thereby than there is in the case of the fifty-sixth embodiment of  FIG. 86 . However, in the fifty-ninth embodiment of  FIG. 89 , similarly with respect to the fifty-eighth embodiment of  FIG. 88 , the outer surface of the chassis of the mobile telephone  5501 , except for the portions of the GUI display unit  3405  and the microphone  23 , is covered by an elastic body  5563 , as a countermeasure against such sound leakage. Herein, the elastic body  5563  is bonded so as to be integrated with the chassis of the mobile telephone  5501 . The portion of the GUI display unit  3405  then becomes an opening part so as not to hinder GUI operation. The portion of the microphone  23  is configured as the microphone cover unit  467  having a sponge-like or similar structure that will not hinder the air conduction of audio, similarly with respect to the fifth embodiment of  FIG. 11 . This is a point of similarity with the fifty-eighth embodiment of  FIG. 88 . 
     The elastic body  5563  for covering the outer surface of the chassis of the mobile telephone  5501  is preferably made of a vinyl-based, urethane-based, or other type of vibration insulation material and cushioning material, similarly with respect to the fifty-eighth embodiment of  FIG. 88 . Due to the above configuration, in the fifty-ninth embodiment of  FIG. 89  as well, the vibration of a large portion of the surface area of the surface of the chassis of the mobile telephone  5501  is suppressed by the weight and elasticity of the covering elastic body  5563  in both the interior and exterior directions over the amplitude of vibration, and vibration energy is also absorbed. The surface of the mobile telephone  5501 , which is contact with the air, is also given elasticity. The air conduction sound generated from the surface of the chassis of the mobile telephone  5501 , caused by the vibration of the cartilage conduction vibration source  2525 , is thereby attenuated. On the other hand, because the elastic body  5563  has an acoustic impedance approximating that of the ear cartilage, there is favorable cartilage conduction to the ear cartilage from the upper part corner  3824 , which is a suitable site to be brought up against the tragus or other part of the ear cartilage. A further point of similarity with the fifty-eighth embodiment of  FIG. 88  is that the manner in which the elastic body  5563  covers the surface of the chassis of the mobile telephone  5501  also functions as a protection for when the mobile telephone  5501  collides with an external unit. 
     Sixtieth Embodiment 
       FIG. 90  is a perspective view and a cross-sectional view relating to a sixtieth embodiment according to an aspect of the present invention, which is configured as a mobile telephone  5601 . The sixtieth embodiment is consistent with the forty-sixth embodiment illustrated in  FIG. 69 , except for a configuration intended as a countermeasure against sound leakage due to air conduction sound, and therefore shared portions are given like reference numerals, and a description thereof has been omitted unless there is a need. 
     In the sixtieth embodiment of  FIG. 90 , similarly with respect to the forty-sixth embodiment of  FIG. 69 , elastic body units  5663   a  and  5663   b , serving as protectors, are provided to the two corners of the upper part of the mobile telephone  5601 . The inner sides thereof have a dual purpose as units for holding both ends of the cartilage conduction vibration source  2525 , and the outer sides have a dual purpose as cartilage conduction units for making contact with the ear cartilage. The elastic body units  5663   a  and  5663   b  utilize an elastic material having an acoustic impedance approximating that of ear cartilage (a silicone rubber; a mixture of a silicone rubber and a butadiene rubber; a natural rubber; a structure formed using these varieties of rubber in which air bubbles are sealed; a structure, such as can be seen in transparent packaging sheet materials and the like, in which a layer of groups of air bubbles is sealed separated by a thin film of synthetic resin; or the like). 
     In the sixtieth embodiment of  FIG. 90  as well, a substantial component of the vibration of the elastic body units  5663   a  and  5663   b  for holding the cartilage conduction vibration source  2525  is conducted to the chassis of the mobile telephone  5601 , and the front surface and rear surface of the mobile telephone  5601 , which account for a large surface area of the outer surfaces thereof, are made to vibrate, thus generating air conduction sound. However, in the sixtieth embodiment of  FIG. 90  as well, there extends in a sheet-shaped manner from the elastic body units  5663   a  and  5663   b  an elastic body  5663  composed of the same material, as a countermeasure against sound leakage caused by the aforesaid air conduction sound; the elastic body  5663  covers the outer surfaces of the mobile telephone  5601  except for the portions of the GUI display unit (the same part as an GUI display unit  3405  in  FIGS. 88 and 99 ) and the microphone  23 . In the sixtieth embodiment of  FIG. 90  as well, similarly with respect to the fifty-eighth embodiment of  FIG. 88  and the fifty-ninth embodiment of  FIG. 89 , the elastic body  5663  is bonded so as to be integrated with the chassis of the mobile telephone  5601 . The portion of the GUI display unit  3405  then becomes an opening part so as not to hinder GUI operation. The portion of the microphone  23  is configured as the microphone cover unit  467  having a sponge-like or similar structure that will not hinder the air conduction of audio, similarly with respect to the fifth embodiment of  FIG. 11 . This is a point of similarity with the fifty-eighth embodiment of  FIG. 88  and the fifty-ninth embodiment of  FIG. 89 . 
     Due to the above configuration, in the sixtieth embodiment of  FIG. 90  as well, the vibration of a large portion of the surface area of the surface of the chassis of the mobile telephone  5601  is suppressed by the weight and elasticity of the covering elastic body  5663  in both the interior and exterior directions over the amplitude of vibration, and vibration energy is also absorbed. The surface of the mobile telephone  5601 , which is in contact with the air, is also given elasticity. The air conduction sound generated from the surface of the chassis of the mobile telephone  5601 , caused by the vibration of the cartilage conduction vibration source  2525 , is thereby attenuated. The manner in which the elastic body  5663  covers the surface of the chassis of the mobile telephone  5601  also functions as a protection for those portions other than the elastic body units  5663   a  and  5663   b.    
     Sixty-First Embodiment 
       FIG. 91  is a perspective view and a cross-sectional view relating to a sixty-first embodiment according to an aspect of the present invention, which is configured as a mobile telephone  5701 . The sixty-first embodiment is consistent with the fifty-fifth embodiment illustrated in  FIG. 83 , except for a configuration intended as a countermeasure against sound leakage due to air conduction sound, and therefore shared portions are given like reference numerals, and a description thereof has been omitted unless there is a need. 
     In the sixty-first embodiment of  FIG. 91 , similarly with respect to the fifty-fifth embodiment illustrated in  FIG. 83 , both ends of the cartilage conduction vibration source  2525  are held by the cartilage conduction units  5124  and  5126  composed of a hard material, and are supported by the chassis of the mobile telephone  5701  via the elastic bodies  5165   b  and  5165   a . In such a structure, as has already been described in the fifty-eighth embodiment of  FIG. 88 , there is slight vibration conveyed to the chassis of the mobile telephone  5701 , thus generating sound leakage due to air conduction sound generated from the front surface and rear surface thereof. As a countermeasure to this sound leakage, the sixty-first embodiment of  FIG. 91  has a pressure-fixation structure  5701   h  made of a screwed-in metal sheet or the like for pressing and affixing internal configuration components  5748  of the mobile telephone  5701 , including a battery and the like, to the inner surface of the chassis of the mobile telephone  5701 . The weight of the internal configuration  5748 , including the battery and the like, is thereby integrated with the chassis of the mobile telephone  5701 , and the vibration of a large portion of the surface area of the chassis is thereby suppressed across both the interior and exterior directions in the amplitude thereof, wherefore the generation of air conduction sound is attenuated. 
     In the sixty-first embodiment of  FIG. 91 , there is further a surplus space within the chassis of the mobile telephone  5701 , which is filled in with a sound-absorbent packing material  5701   i  composed of nonwoven cloth or the like. The surplus space within the chassis of the mobile telephone  5701  is thereby finely sub-divided and the air within the chassis is prevented from resonating, thus attenuating the generation of air conduction sound. To facilitate understanding,  FIG. 91C  provides a simplified depiction of the manner in which the internal configuration  5748 , the pressure fixation structure  5701   h , and the sound-absorbent packing material  5701   i  are packed, but the structure therefor is in practice very complex; also, the pressure fixation structure  5701   h  is not limited to pressing and fixing the internal configuration  5748  only to the rear surface side of the mobile telephone  5701 , as is depicted. For the fine sub-division of the surplus space within the chassis of the mobile telephone  5701 , a barrier wall also may be provided to the inner side of the chassis, instead of packing in the sound-absorbing packing material  5701   i.    
     The implementation of the various features of the present invention illustrated by the embodiments above is not to be limited to the respective embodiments above. For example, in  FIGS. 88 to 90  above, on the rear surface and other portions accounting for a large surface area of the outer surfaces of the mobile telephone, the width of the cross-sections of the elastic bodies for covering has been depicted as being approximately equivalent to the width of the cross-section of the chassis. However, as long as the strength of the chassis is maintained, the thickness of the cross-section of the chassis can be reduced as much as possible, and the thickness of the cross-section of the elastic body for covering the same can be increased as much as possible, so that the chassis theoretically comprises the elastic body, and the effect of preventing sound leakage is improved. At such a time, a configuration in which the barrier wall for finely sub-dividing the surplus space is provided to the interior of the chassis is further advantageous in retaining strength, and contributes to rendering the chassis thinner. 
     In the sixtieth embodiment illustrated in  FIG. 90 , the elastic body units  5663   a  and  5663   b  having multiple purposes as protectors, as parts for holding both ends of the cartilage conduction vibration source  2525 , and as cartilage conduction units are contiguous with the elastic body  5663 , being of the same material, but there is no limitation to such a configuration. For example, the elastic body units  5663   a  and  5663   b  may be components that are separated from the elastic body  5663 , or may necessarily not be in contact. The elastic body units  5663   a  and  5663   b  may also be constituted of a different material from that of the elastic body  5663 . 
     Further, for the sake of simplicity, the fifty-eighth to sixtieth embodiments illustrated in  FIGS. 88 to 90  depict configurations in which the vibration of the chassis of the mobile telephone is covered and suppressed by an exterior elastic body, and the sixty-first embodiment of  FIG. 91  depicts a configuration in which the vibration of the chassis of the mobile telephone is suppressed by the pressure fixation of the weight of the internal configuration of the mobile telephone. However, there is no limitation to the case where these elements are employed separately, as in the embodiments, but rather the configuration may be such that the two are used concurrently and the vibration of the interior and exterior of the chassis of the mobile telephone is suppressed therefrom. 
     Sixty-Second Embodiment 
       FIG. 92  is a perspective view and a side view of a sixty-second embodiment according to an aspect of the present invention, configured as a land-line telephone  5800 . As shown in perspective view in  FIG. 92(A) , the land-line telephone  5800  includes a telephone base station  5801  and a cordless handset  5881 . The telephone base station  5801  is furnished with a display unit  5805 , a videoconferencing camera  5817 , a videoconferencing microphone  5823 , a videoconferencing speaker  5851 , and the like. 
       FIG. 92(B)  shows the handset  5881  of the land-line telephone  5800  in a state positioned upright in a charger  5848 . This handset  5881  is identical to the cordless handset  5881  in  FIG. 92(A) , and is therefore illustrated with the same symbol. As shown in  FIG. 92  (B), the cordless handset or the handset  5881  (hereinafter, both shall be denoted as “cordless handset  5881 ”) has a cartilage conduction unit  5824  that defines a gentle convex face; when the cordless handset  5881  is placed against the ear, this cartilage conduction unit  5824  fits naturally into a depression of the ear having the external auditory meatus as the bottom, coming into contact with the ear cartilage over a wide area. The cordless handset (or handset)  5881  also has an outgoing-talk unit  1423  comparable to that shown in the mobile telephone embodiment. 
       FIG. 92(C)  illustrates a side surface of the cordless handset (or handset)  5881 , and shows the cordless handset (or handset)  5881  placed against an ear  30 , at which time the gentle convex face of the cartilage conduction unit  5824  fits into the depression of the ear having the external auditory meatus as its bottom, and comes into contact with the ear cartilage over a wide area. As will be clear from the side view in  FIG. 92(C) , in the sixty-second embodiment, the cartilage conduction unit  5824  has a shape defined by a portion of a spherical face. In an ordinary handset, the ear-contacting part has a concave face for forming a closed space to the front of the ear; however, the handset for cartilage conduction according to the present invention conversely has a convex face, and can be given a natural shape readily fitting into the depression of the ear having the external auditory meatus as its bottom. 
       FIG. 93  is a block diagram of the sixty-second embodiment, in which identical components have been assigned the same reference numerals as in  FIG. 92 . Additionally, as the configuration shown in the block diagram has much in common with the seventeenth embodiment of  FIG. 29 , the same reference numerals as those assigned to these parts have been assigned to corresponding portions. Descriptions of these identical or corresponding portions are omitted, unless there is a particular need. Even for portions not assigned identical numerals, for example, the videoconferencing camera  5817 , the portion corresponds to the videoconferencing inside camera  17  in the mobile telephone  1601  of  FIG. 29 , and the functions thereof are basically identical. Moreover, while the sixty-second embodiment pertains to a land-line telephone and therefore represents a different system from a mobile telephone, the telephone functionality is basically identical, and therefore the illustration of a telephone function unit  5845  in  FIG. 93  is similar. This is true of the power supply unit as well: while the power source differs, the functions are basically identical, and therefore the same reference numeral as in  FIG. 29  is assigned.  FIG. 93  also illustrates charging contacts  1448   a  and  1548   a , for charging the cordless handset (or handset)  5881  while placed in the telephone base station  5801  or the charger  5848 . 
       FIG. 94  shows side cross sectional views of cordless handsets in the sixty-second embodiment of  FIG. 92  and modification examples thereof, showing the relationship of a piezoelectric bimorph element constituting the cartilage conduction vibration source, and the cartilage conduction unit having a convex face.  FIG. 94(A)  shows a side cross sectional view of the cordless handset  5881  of the sixty-second embodiment, in which a vibration conductor  5827  is affixed to the inside of a cartilage conduction unit  5824 , with the center part of a piezoelectric bimorph element  2525   d  being supported by this vibration conductor  5827 . Both ends of the piezoelectric bimorph element  2525   d  can vibrate freely, the counteraction thereof being transmitted to the cartilage conduction unit  5824  via the vibration conductor  5827 . 
       FIG. 94(B)  is a side cross sectional view of a cordless handset  5881   a  in a first modification example of the sixty-second embodiment. Whereas the cartilage conduction unit  5824  in the cordless handset  5881   a  of the sixty-second embodiment was a partial spherical face, the cartilage conduction unit  5824   a  in the first modification example has an acute-angled conical (cone) shape. The configuration whereby the vibration conductor  5827   a  is affixed to the inside of the cartilage conduction unit  5824   a , and supports the center part of a piezoelectric bimorph element  2525   e , is shared with the sixty-second embodiment. 
       FIG. 94(C)  is a side cross sectional view of a cordless handset  5881   b  in a second modification example of the sixty-second embodiment. As in the first modification example, the cartilage conduction unit  5824   b  in the cordless handset  5881   b  of the second modification example has an acute-angled conical (cone) shape. In the second modification example of  FIG. 94(C) , a vibration conductor  5827   b  is affixed to the inside of the cartilage conduction unit  5824   b , and supports one end of a piezoelectric bimorph element  2525   f . The other end of the piezoelectric bimorph element  2525   f  can vibrate freely, the counteraction thereof being transmitted to the cartilage conduction unit  5824   b  via the vibration conductor  5827   b.    
       FIG. 94(D)  is a side cross sectional view of a cordless handset  5881   c  in a third modification example of the sixty-second embodiment. As in the first modification example and the second modification example, the cartilage conduction unit  5824   c  in the cordless handset  5881   c  of the third modification example has an acute-angled conical (cone) shape. In the third modification example of  FIG. 94(D) , a low-end piezoelectric bimorph element  2525   g  and a high-end piezoelectric bimorph element  2525   h  are respectively bonded directly to the inside of the cartilage conduction unit  5824   c , such that the vibrating surface side thereof is in contact therewith. In so doing, vibration of the piezoelectric bimorph element  2525   g  and the piezoelectric bimorph element  2525   h  is transmitted directly to the cartilage conduction unit  5824   c . In this way, through the complementary use of multiple cartilage conduction vibration sources of different frequency characteristics, the frequency characteristics of cartilage conduction can be improved. 
     In the modification examples of  FIG. 94(B)  to  FIG. 94(D) , the convex-faced cartilage conduction unit is of conical (cone) shape. By adopting such a configuration, the side surface of the conical element (cone) fits into the external auditory meatus, irrespective of individual differences in the size of the external auditory meatus, so that cartilage conduction from the entire circumference of the external auditory meatus can be achieved. 
     Sixty-Third Embodiment 
       FIG. 95  is a cross sectional view relating to a sixty-third embodiment according to an aspect of the present invention, which is configured as stereo headphones  5981 .  FIG. 95  (A) is a cross sectional view of the stereo headphones  5981  in their entirety, which have a right ear cartilage conduction unit  5924  and a left ear cartilage conduction unit  5926 . The right ear cartilage conduction unit  5924  and the left ear cartilage conduction unit  5926  are respectively of conical (cone) convex shape. A piezoelectric bimorph element  2525   i  and a piezoelectric bimorph element  2525   j  are respectively bonded to the inside of the right ear cartilage conduction unit  5924 , such that the vibrating surface side thereof is in contact therewith. This construction is basically one shared with the third modification example of the sixty-second embodiment in  FIG. 94(D) . Likewise, a piezoelectric bimorph element  2525   k  and a piezoelectric bimorph element  2525   m  are respectively bonded to the inside of the left ear cartilage conduction unit  5926 , such that the vibrating surface side thereof is in contact therewith. 
       FIG. 95(B)  and  FIG. 95(C)  describe a feature whereby, by adopting a convex face of conical (cone) shape for the right ear cartilage conduction unit  5924  (and the left ear cartilage conduction unit  5926 ), the right ear cartilage conduction unit  5924  (and the left ear cartilage conduction unit  5926 ) can be made to fit into an external auditory meatus  30   a , irrespective of individual differences in the size of the external auditory meatus  30   a ; and respectively show a representative enlarged section of the right ear cartilage conduction unit  5924  in the sixty-third embodiment.  FIG. 95(B)  shows a case of use of the stereo headphones  5981  by an individual whose external auditory meatus  30   a  is relatively small, in which case a section comparatively towards the distal end of the conical element of the right ear cartilage conduction unit  5924  contacts the entire circumference of the external auditory meatus  30   a . In contrast to this,  FIG. 95(C)  shows a case of use of the stereo headphones  5981  by an individual whose external auditory meatus  30   a  is relatively large, in which case the conical element of the right ear cartilage conduction unit  5924  slips more deeply into the external auditory meatus, so that a section comparatively towards the basal end of the conical element contacts the entire circumference of the external auditory meatus  30   a . However, as will be clear from an examination of  FIG. 95(B)  and  FIG. 95(C) , the depth to which the conical element of the right ear cartilage conduction unit  5924  slips into external auditory meatus  30   a  has no significant effect on cartilage conduction, and by adopting a conical shape for the right ear cartilage conduction unit  5924 , the right ear cartilage conduction unit  5924  can be made to unfailingly contact the entire circumference of the external auditory meatus  30   a  in satisfactory fashion, irrespective of individual differences in the size of the external auditory meatus  30   a . Like the right ear cartilage conduction unit  5924 , the left ear cartilage conduction unit  5926  will also be made to contact the entire circumference of the external auditory meatus  30   a  in satisfactory fashion, irrespective of individual differences in the size of the external auditory meatus  30   a.    
     By configuring a stereo audio output device by using a pair of sound output devices like those of the sixty-third embodiment, having a cartilage conduction unit with a convex face of conical shape, and a cartilage conduction vibration source for transmitting vibration to the cartilage conduction unit, the cartilage conduction units can be slipped in from the left and the right and pressed respectively into the external auditory meatus of each ear, whereby satisfactory contact of the convex face of conical shape of the cartilage conduction unit against the entire circumference of the external auditory meatus can be achieved. 
     In the sixty-third embodiment, the conical elements of the right-ear cartilage conduction unit  5924  and the left-ear cartilage conduction unit  5926  are configured with an obtuse angle like that in the third modification example of the sixty-second embodiment in  FIG. 94(D) ; however, a configuration having an acute angle would be acceptable if needed. In this case, the distal end would be rounded to avoid posing any danger. In the sixty-third embodiment, two piezoelectric bimorph elements each having identical frequency characteristics are bonded to the right-ear cartilage conduction unit  5924  and the left-ear cartilage conduction unit  5926 ; however, ones having different frequency characteristics, like those in the third modification example of the sixty-second embodiment in  FIG. 94(D) , would be acceptable as well. A configuration in which the right-ear cartilage conduction unit  5924  and the left-ear cartilage conduction unit  5926  are each furnished with a single piezoelectric bimorph element would be acceptable as well. In this case, instead of direct adhesion, a configuration in which the element is supported via the vibration conductor, as in the sixty-second embodiment and modification examples thereof in  FIG. 94(A)  to  FIG. 94  (C), would also be acceptable. 
     The features of the several inventions described above are not limited to the aforedescribed embodiments, and implementation in other embodiments is possible. For example, in the aforedescribed sixty-second embodiment and sixty-third embodiment, it would be possible to adopt, as the cartilage conduction vibration source thereof, another vibration source such as an electromagnetic vibrator of the sort shown in other aforedescribed embodiments, instead of piezoelectric bimorph elements. Moreover, whereas the aforedescribed sixty-second embodiment described configuration as a handset of a land-line telephone, and the aforedescribed sixty-third embodiment as headphones, respectively, implementation of the features described above is not limited to these. That is, it is possible for the various features described in relation to providing a convex face to the cartilage conduction vibration unit in the aforedescribed embodiments to be implemented, for example, in a configuration for earphones or in a configuration for a headset, as shown in other aforedescribed embodiments. Implementation in a land-line telephone is not limited to the features shown in the aforedescribed sixty-second embodiment, and it is possible for various features which are shown in yet other embodiments by way of an embodiment such as a mobile telephone, to be implemented in the handset of a land-line telephone, as appropriate. 
     Sixty-Fourth Embodiment 
       FIG. 96  is a perspective view, a cross sectional view, and a top view relating to a sixty-fourth embodiment according to an aspect of the present invention, configured as a mobile telephone  6001 . The sixty-fourth embodiment has much in common with the fifty-fifth embodiment shown in  FIG. 83 , except for the holding structure of the cartilage conduction unit  2525  (hereinafter denoted as piezoelectric bimorph element  2525 ) which is constituted by a piezoelectric bimorph element; therefore corresponding portions have been given like reference numerals, and a description has been omitted unless necessary. 
     In the sixty-fourth embodiment of  FIG. 96 , as in the fifty-fifth embodiment of  FIG. 83 , the main vibration direction of the piezoelectric bimorph element  2525  is oriented orthogonal to a GUI display unit  3405 , and features a characteristic holding structure.  FIG. 96(A)  is a perspective view of the mobile telephone  6001  of the sixty-fourth embodiment seen from the front face; the structure for holding the piezoelectric bimorph element  2525  is produced by integral molding of a right-ear cartilage conduction unit  6024 , a left-ear cartilage conduction unit  6026 , and a linking unit  6027  linking these, from a hard material. The piezoelectric bimorph element  2525  is supported at the inside of the right-ear cartilage conduction unit  6024 , whereby it is possible for vibration thereof to be transmitted directly to the right ear cartilage contacted by the right-ear cartilage conduction unit  6024 . Further, vibration of the piezoelectric bimorph element  2525  supported by the right-ear cartilage conduction unit  6024  is transmitted as well to the left-ear cartilage conduction unit  6026  through the linking unit  6027  which serves as a vibration conductor, whereby it is possible to achieve cartilage conduction, without the left-ear cartilage conduction unit  6026  contacting the left ear cartilage. 
     Further, the aforedescribed hard, integrally molded structure is attached to the chassis of the mobile telephone  6001  via an elastic body  6065  made of ethylene resin, urethane resin, or the like, so that the hard, integrally molded structure directly contacts the chassis of the mobile telephone  6001 . Consequently, the elastic body  6065  functions as a vibration isolating material and a cushioning material, and also mitigates transmission of vibration of the piezoelectric bimorph element  2525  to the chassis of the mobile telephone  6001 . In so doing, the risk of bothering people nearby, or loss of privacy, due to audible receiver sounds caused by air-conducted sound generated by vibration of the chassis of the mobile telephone  6001  can be prevented. Moreover, because the elastic body  6065  transmits vibration for the purpose of cartilage conduction, good cartilage conduction can be obtained even when the front surface side of a corner of the elastic body  6065  is placed against the ear cartilage. 
       FIG. 96(B)  is a top cross sectional view of the mobile telephone  6001  taken in the B 1 -B 1  cross section in  FIG. 96(A)  (a cross section of the mobile telephone  6001  cut through the center).  FIG. 96(B)  shows a top center cross section, from which it may be appreciated that the piezoelectric bimorph element  2525  is supported in cantilever fashion to the inside of the right-ear cartilage conduction unit  6024  in the integrally molded structure, with the side thereof at which a terminal  2525   b  is furnished serving as the held end. While the details of the structure are omitted from the illustration, the inside of the right-ear cartilage conduction unit  6024 , which holds the piezoelectric bimorph element  2525  via the terminal  2525   b , is provided with a connection space and a connecting wire leadout slot therefor. 
     Meanwhile, as will be clear from  FIG. 96(B) , the other end  2525   c  of the piezoelectric bimorph element  2525  is a free vibrating end, to which an inertial weight (inertial bob)  6025  has been attached. The inertial weight  6025  increases the eight of the other end  2525   c , thereby suppressing movement of the other end  2525   c  through inertia, and increasing the vibration energy drawn from the held end side through vibration of the piezoelectric bimorph element  2525  as counteraction thereof. Stated another way, the held end side of the piezoelectric bimorph element  2525  increases the component that vibrates together with the hard, integrally molded structure with the inertial weight  6025  side as the fulcrum point. 
     Moreover, as will be clear from  FIG. 96(B) , the linking unit  6027  is thinner than the right-ear cartilage conduction unit  6024  and the left-ear cartilage conduction unit  6026 , so that the right-ear cartilage conduction unit  6024  and the left-ear cartilage conduction unit  6026  are linked in “shoulder pole” fashion so as to bypass the internal components of the mobile telephone  6001 . In so doing, it is possible to devise a layout for an in-camera  6017  and the like, which are preferably situated in the upper part of the mobile telephone  6001 . The thickness of the linking unit  6027  need merely be one sufficient to achieve rigid fastening of the positional relationships of the right-ear cartilage conduction unit  6024  and the left-ear cartilage conduction unit  6026 , so linking structures other than that shown in  FIG. 96  are possible. Moreover, seen from the standpoint of functionality as a cartilage conduction unit as well, it is sufficient for the linking unit  6027  to have a relatively small cross sectional area, and therefore there is a greater degree of freedom in relation to placement of components inside the mobile telephone  6001  in relation to the linking unit  6027 . 
       FIG. 96(C)  is an exterior view of the mobile telephone  6001  seen from the top face, in which the integrally molded structure including the right-ear cartilage conduction unit  6024 , the left-ear cartilage conduction unit  6026 , and the linking unit  6027  linking these is exposed. An elastic body  6065  sandwiching these from both sides is exposed as well. In  FIG. 96(C) , the interrelationships of the internal piezoelectric bimorph element  2525 , the inertial weight  6025 , and the in-camera  6017 , as well as the boundary lines of the right-ear cartilage conduction unit  6024 , the linking unit  6027 , and the left-ear cartilage conduction unit  6026 , are shown by broken lines. 
       FIG. 96(D)  is an upper part cross sectional side view of the mobile telephone  6001  taken in the B 2 -B 2  cross section in  FIG. 96(A) -(C). In this cross sectional side view as well, the right-ear cartilage conduction unit  6024  is attached to the chassis of the mobile telephone  6001  via the elastic body  6065  serving as an isolating material and a cushioning material, so as to have no direct contact with the mobile telephone  6001  chassis. 
     Sixty-Fifth Embodiment 
       FIG. 97  is a perspective view, a cross sectional view, and a top view of a sixty-fifth embodiment according to an aspect of the present invention, configured as a mobile telephone  6101 . The sixty-fifth embodiment has much in common with the sixty-fourth embodiment of  FIG. 96 , except for a different shape for a right-ear cartilage conduction unit  6124 , a left-ear cartilage conduction unit  6126 , and a linking unit  6127 , and in association therewith, a different shape for an elastic body  6165 . Therefore, the discussion focuses mainly on the different portions, assigning like symbols to and the common portions and omitting descriptions thereof unless necessary. 
     From the perspective view in  FIG. 97(A)  it will be clear that in the sixty-fifth embodiment, the right-ear cartilage conduction unit  6124 , the left-ear cartilage conduction unit  6126 , and the linking unit  6127  linking these are integrally molded from hard material, to a shape covering the upper part of the mobile telephone  6101 . In association therewith, the elastic body  6165  is interposed at a location sandwiched vertically between the integrally molded structure and the chassis of the mobile telephone  6101 , so that there is no direct contact between the two. 
       FIG. 97(B)  is an upper part cross sectional view of the mobile telephone  6101  in the B 1 -B 1  cross section in  FIG. 97(A) . Because the B 1 -B 1  cross section is a cross section taken of the mobile telephone  6101  cut from the center, there is basically no difference from the sixty-fourth embodiment of  FIG. 96(B) ; however, when the B 1 -B 1  cross section is shifted in parallel fashion to approach towards the front surface side or the back face side of the mobile telephone  6101 , the resultant cross section differs from the sixty-fourth embodiment of  FIG. 96 , as will be clear from  FIG. 97(A) . As will be appreciated from  FIG. 97(B) , in the sixty-fifth embodiment, the piezoelectric bimorph element  2525  is supported in cantilever fashion to the inside of the right-ear cartilage conduction unit  6124 , with an end part  2525   c  not furnished with a terminal  2525   c  serving as the held end. Meanwhile, the end part of the piezoelectric bimorph element  2525  where the terminal  2525   b  is furnished constitutes a free vibrating end, to which an inertial weight  6125  is attached. While the details of the structure are omitted from the illustration, the piezoelectric bimorph element  2525  is attached via the terminal  2525   b  to the inside of the inertial weight  6125 , which is provided with a connection space and a connecting wire leadout slot therefor. Selection of the held end and the inertial weight attachment end in this manner is not a characteristic feature of the sixty-fifth embodiment, and the attachment method of the sixty-fifth embodiment may be adopted in the sixty-fourth embodiment, or vice-versa. 
     As will be clear from  FIG. 97(B) , in the sixty-fifth embodiment as well, the linking unit  6127  is thinner than the right-ear cartilage conduction unit  6124  and the left-ear cartilage conduction unit  6126 , so that the right-ear cartilage conduction unit  6124  and the left-ear cartilage conduction unit  6126  are linked in “shoulder pole” fashion to bypass the internal components of the mobile telephone  6101 . In the sixty-fifth embodiment, it is possible in terms of strength for the linking unit  6127  to be even thinner, as the linking unit  6127  has considerable width and covers the entire top face. Further, depending on the design, it is possible to configure the linking unit  6127  to cover not only the top face, but also to wrap around to the front surface side and the back face side, so that the linking unit  6127  can be even thinner. 
       FIG. 97(C)  is an exterior view of the mobile telephone  6101  seen from the top face, in which the integrally molded structure including the right-ear cartilage conduction unit  6124 , the left-ear cartilage conduction unit  6126 , and the linking unit  6127  linking these is visible. In  FIG. 97(C)  as well, the interrelationships of the internal piezoelectric bimorph element  2525 , an inertial weight  6125 , and an in-camera  6117 , as well as the boundary lines of the right-ear cartilage conduction unit  6124 , the linking unit  6127 , and the left-ear cartilage conduction unit  6126 , are shown by broken lines. 
       FIG. 97(D)  is an upper part cross sectional side view of the mobile telephone  6101  taken in the B 2 -B 2  cross section in  FIG. 97(A) -(C). In the cross sectional side view of the sixty-fifth embodiment as well, the right-ear cartilage conduction unit  6124  is attached to the chassis of the mobile telephone  6101  via an elastic body  6165  serving as an isolating material and a cushioning material, so as to have no direct contact with the mobile telephone  6101  chassis. 
     Sixty-Sixth Embodiment 
       FIG. 98  is a perspective view, a cross sectional view, and a top view relating to a sixty-sixth embodiment according to an aspect of the present invention, configured as a mobile telephone  6201 . The sixty-sixth embodiment likewise has much in common with the sixty-fourth embodiment of  FIG. 96  and the sixty-fifth embodiment of  FIG. 97 , except for a different shape for a right-ear cartilage conduction unit  6224 , a left-ear cartilage conduction unit  6226 , and a linking unit  6227 , and in association therewith, a different shape for an elastic body  6265 . Therefore, the discussion focuses mainly on the different portions, assigning like symbols to and the common portions and omitting descriptions thereof unless necessary. 
     From the perspective view in  FIG. 98(A)  it will be clear that in the sixty-sixth embodiment, the right-ear cartilage conduction unit  6224  and the left-ear cartilage conduction unit  6226  are exposed to the outside, while the linking unit  6227  which links these inside the chassis is not visible from the outside. In association therewith, from the outside, the elastic body  6265  is visible only in portions isolating the right-ear cartilage conduction unit  6224  and the left-ear cartilage conduction unit  6226  from the chassis of the mobile telephone  6201 , and there is no direct contact between the right-ear cartilage conduction unit  6224  and the left-ear cartilage conduction unit  6226  and the chassis of the mobile telephone  6201 . Consequently, the sixty-sixth embodiment may be said to have an external appearance in common with that of the fifty-fifth embodiment of  FIG. 83 , albeit in relation to the external appearance only. The internal structure does differ however, in the manner described below. 
       FIG. 98(B)  is an upper part cross sectional side view of the mobile telephone  6201  taken in the B 1 -B 1  cross section in  FIG. 98(A) . From  FIG. 98(B) , it will be clear that in the sixty-sixth embodiment, the right-ear cartilage conduction unit  6224  and the left-ear cartilage conduction unit  6226  are linked inside the chassis by the linking unit  6227 . The linking unit  6227  does not contact the chassis interior. A function of transmitting to the left-ear cartilage conduction unit  6226  the vibration of the right-ear cartilage conduction unit  6224  which supports the piezoelectric bimorph element  2525 , and a function of rigid integration of the right-ear cartilage conduction unit  6224  and the left-ear cartilage conduction unit  6226 , are possible with the linking unit  6227  inside the chassis as in the sixty-sixth embodiment. 
       FIG. 98(C)  is an exterior view of the mobile telephone  6201  from the top face; at both corners in the upper part of the mobile telephone  6201 , the elastic body  6265  is visible, blocking the right-ear cartilage conduction unit  6224  and the left-ear cartilage conduction unit  6226 , respectively, as well as vibration thereof, from the chassis. In  FIG. 98(C)  as well, the interrelationships of the internal piezoelectric bimorph element  2525 , an inertial weight  6225 , an in-camera  6217 , and the linking unit  6227  are shown by broken lines. 
       FIG. 98(D)  is an upper part cross sectional side view of the mobile telephone  6201  taken in the B 1 -B 1  cross section in  FIG. 98(A) -(C) The cross sectional side view of the ninety-eighth embodiment is basically no different from the sixty-fifth embodiment of  FIG. 97(B) ; however, when the B 2 -B 2  cross section is shifted in parallel fashion to approach towards the center side from a side surface of the mobile telephone  6201 , the resultant cross section differs from the sixty-fifth embodiment of  FIG. 97 , as is clear from  FIG. 98(A) . 
     In the sixty-fourth to sixty-sixth embodiments of the preceding  FIGS. 96 to 98 , the main vibration direction of the piezoelectric bimorph element  2525  was described as being oriented orthogonal to the GUI display unit  3405 . However, the orientation at which the piezoelectric bimorph element  2525  is held in these embodiments is not limited to this, and the main vibration direction of the piezoelectric bimorph element  2525  may be oriented parallel to the GUI display unit  3405  (the vertical direction of the mobile telephone). Setting of the main vibration direction of the piezoelectric bimorph element  2525  is accomplished in the manner discussed in detail previously in the fifty-sixth embodiment of  FIG. 86  in relation to the fifty-fifth embodiment of  FIG. 83 . 
     Sixty-Seventh Embodiment 
       FIG. 99  is a perspective view and a cross sectional view relating to a sixty-seventh embodiment according to an aspect of the present invention, configured as a mobile telephone  6301 . In the sixty-seventh embodiment, the structure of the sixty-sixth embodiment of  FIG. 98 , in which the right-ear cartilage conduction unit and the left-ear cartilage conduction unit are rigidly linked by a linking unit, is applied in the fifty-fifth embodiment of  FIG. 83 ; however, other features are common to both, and therefore these common portions have been assigned the same symbols as in the fifty-fifth embodiment of  FIG. 83 , omitting descriptions thereof unless necessary. 
     As will be clear from  FIG. 99(B) , in the sixty-seventh embodiment, a right-ear cartilage conduction unit  6324  and a left-ear cartilage conduction unit  6326  are linked rigidly into an integrated body inside the chassis by a linking unit  6327 . The linking unit  6327  does not contact the chassis interior. This feature of the sixty-seventh embodiment may be said to belong in common to the sixty-sixth embodiment of  FIG. 98 . However, viewed in terms of functionality, in the sixty-seventh embodiment of  FIG. 99 , vibration of the piezoelectric bimorph element  2525  is transmitted directly to the right cartilage conduction unit  6324  and the left cartilage conduction unit  6326 , respectively, and in this sense alone, the vibration transmission path afforded by the linking unit  6327  is redundant. 
     However, even in cases in which, as the sixty-seventh embodiment, it is not necessary to transmit vibration between the right cartilage conduction unit  6324  and the left cartilage conduction unit  6326 , integration of the two by the linking unit  6327  is highly significant in terms of achieving stable attachment to the chassis. To describe in more specific terms, ordinarily, when an elastic body  6365  disposed between the chassis, and the right cartilage conduction unit  6324  and the left cartilage conduction unit  6326 , is made softer or thicker in order to suppress transmission of vibration between the two, the result of doing so is that the hold of the right cartilage conduction unit  6324  and the left cartilage conduction unit  6326  on the chassis becomes unstable. In contrast to this, when the right cartilage conduction unit  6324  and the left cartilage conduction unit  6326  are rigidly linked by the linking unit  6327  as in the sixty-seventh embodiment, the relative positions of both are maintained, so that both can be more stably attached to the chassis, even when the elastic body  6365  is made softer or thicker. 
     Sixty-Eighth Embodiment 
       FIG. 100  is a cross sectional view relating to a sixty-eighth embodiment according to an aspect of the present invention, configured as a mobile telephone  6401 . In the sixty-eighth embodiment, the structure of the sixty-fifth embodiment of  FIG. 97 , in which the right-ear cartilage conduction unit and the left-ear cartilage conduction unit are rigidly linked by a linking unit, is applied in the fifty-second embodiment of  FIG. 77 ; however, other features are shared by both, and therefore these common portions have been assigned the same symbols as in the fifty-second embodiment of  FIG. 77 , omitting descriptions thereof unless necessary. 
     In the sixty-eighth embodiment of  FIG. 100 , in the same manner as in the sixty-fifth embodiment of  FIG. 97 , a right-ear cartilage conduction unit  6424 , a left-ear cartilage conduction unit  6426 , and a linking unit  6427  linking these are integrally molded from a hard material, to a shape covering the upper part of the mobile telephone  6401 . An elastic body  6465  is interposed at a location sandwiched vertically between this integrally molded structure and the chassis of the mobile telephone  6401 , so that there is no direct contact between the two. A right-ear piezoelectric bimorph element  2525   q  is attached to the right-ear cartilage conduction unit  6424 , and a left-ear piezoelectric bimorph element  2525   p  to the left-ear cartilage conduction unit  6426 , respectively, doing so such that the elements are supported at one side thereof by a cantilever structure. As in the seventy-seventh embodiment, the right-ear piezoelectric bimorph element  2525   q  and the left-ear piezoelectric bimorph element  2525   p  are controllable in mutually independent fashion. 
     In the sixty-eighth embodiment of  FIG. 100 , in the same manner as in the sixty-seventh embodiment of  FIG. 99 , the primary significance of the linking unit  6427  is to rigidly link the right-ear cartilage conduction unit  6424  and the left-ear cartilage conduction unit  6326 , to maintain the relative positions of both, so that both can be attached in a more stable manner to the chassis, even when the elastic body  6465  is made softer or thicker. 
     In the sixty-eighth embodiment of  FIG. 100 , further, vibration of the left-ear piezoelectric bimorph element  2525   p  is transmitted towards the direction of the right-ear cartilage conduction unit  6424 , and vibration of the right-ear piezoelectric bimorph element  2525   q  is transmitted towards the direction of the left-ear cartilage conduction unit  6426 , via the linking unit  6427 . In this manner, in the sixty-eighth embodiment, vibration of the left-ear piezoelectric bimorph element  2525   p  and vibration of the right-ear piezoelectric bimorph element  2525   q  become admixed within the integrally molded structure of the right-ear cartilage conduction unit  6424 , the left-ear cartilage conduction unit  6426 , and the linking unit  6427  linking these. As a result, when vibrations of mutually reversed waveform are generated by the left-ear piezoelectric bimorph element  2525   p  and the right-ear piezoelectric bimorph element  2525   q , the vibrations cancel out each other within the integrally molded structure, suppressing the occurrence of air-conducted sound based on vibration transmitted from the integrally molded structure to the chassis of the mobile telephone  6401 . In this state as well, when either the right-ear cartilage conduction unit  6424  or the left-ear cartilage conduction unit  6426  is placed in contact with ear cartilage, the vibration of the right-ear piezoelectric bimorph element  2525   q  or the right-ear piezoelectric bimorph element  2525   p , which are directly held thereby, will be greater than the vibration traveling through the linking unit  6427 , and therefore the differential thereof will be conducted to the ear cartilage in satisfactory fashion. 
     The various features shown in the preceding embodiments are not limited to implementation in the respective embodiments, and implementation in various other embodiments is possible. For example, by modifying the sixty-eighth embodiment of  FIG. 100  to omit the right-ear piezoelectric bimorph element  2525   q , implementation in accordance with the sixty-fifth embodiment of  FIG. 97  is possible. Stated another way, because vibration of the piezoelectric bimorph element  2525   p , which is supported by the left-ear cartilage conduction unit  6426 , is transmitted to the right-ear cartilage conduction unit  6424  as well through the linking unit  6427 , it is possible to achieve good cartilage conduction, despite the fact that the right-ear cartilage conduction unit  6424 , which does not hold a piezoelectric bimorph element, is placed in contact against the cartilage of the right ear. As may be seen from this modification example, the arrangement for holding the cartilage conduction vibration source which transmits vibration through the linking unit is not limited to an arrangement in which the piezoelectric bimorph element  2525  is held in a sideways long direction as in the sixty-fifth embodiment of  FIG. 97 , and it would be possible for the piezoelectric bimorph element  2525   p  to be held in a vertical long direction as in the aforedescribed modification example of the sixty-eighth embodiment of  FIG. 100 . These are merely examples, and it would be possible for cartilage conduction vibration sources to be to arranged and held in any of various other formats and orientations, according to the layout of the various components inside the mobile telephone. 
     Sixty-Ninth Embodiment 
       FIG. 101  is a system configuration diagram and a usage description diagram of a sixty-ninth embodiment according to an aspect of the present invention. As shown in  FIG. 101(A) , the sixty-ninth embodiment is constituted as a mobile telephone system comprising an ordinary mobile telephone  1601 , and an ultra-compact mobile telephone  6501  having a cartilage conduction unit  6524 . The two are capable of short-range communication by radio waves  6585  of a communication system such as Bluetooth™ or the like. The mobile telephone system of the sixty-ninth embodiment has much in common with the sixteenth embodiment of  FIG. 27  and  FIG. 28  and with the seventeenth embodiment shown in the block diagram of  FIG. 29 . Therefore, the description of the sixty-ninth embodiment, as relates to the external appearance, is based on  FIG. 27 ; and in as relates to the internal configuration, is based on the block diagram of  FIG. 29 , assigning the same reference numerals to the common portions, and omitting descriptions unless necessary. 
     As mentioned above, the sixty-ninth embodiment of  FIG. 101  differs from the sixteenth embodiment and the seventeenth embodiment in that a cartilage conduction output portion capable of short-range communication with the ordinary mobile telephone  1601  is constituted as the ultra-compact mobile telephone  6501  which is capable of functioning independently. It is possible, using the ultra-compact mobile telephone  6501 , to make call operations directed to the ordinary mobile telephone, through an operating unit  6509  and a display unit  6505 . The characteristic features of this embodiment reside in the outgoing-talk unit and the incoming-talk unit thereof. First, with regard to the incoming-talk unit, the cartilage conduction unit  6524  is situated in a corner of the upper part of the ultra-compact mobile telephone  6501 , and a piezoelectric bimorph element  2525  is held in cantilever fashion in a longitudinal direction in the interior thereof. In this sense, the configuration of the ultra-compact mobile telephone  6501  of the sixty-ninth embodiment is shared with the forty-third embodiment of the  FIG. 66 . Meanwhile, the outgoing-talk unit is furnished with a contact type bone conduction microphone  6523  situated close to a corner of the lower part of the ultra-compact mobile telephone  6501 . The ultra-compact mobile telephone  6501  is used by placing the cartilage conduction unit  6524  in contact with the ear cartilage of the tragus or the like, while placing the bone conduction microphone  6523  against the cheekbone or lower jawbone. 
       FIG. 101(B)  shows a state in which, just as shown in  FIG. 2(A) , the cartilage conduction unit  6524  is placed in contact with the ear cartilage of the tragus or the like, with the display unit  6505  oriented to face the cheek, and the bone conduction microphone  6523  is placed against the cheekbone. In  FIG. 101(B) , the cartilage conduction unit  6524  and the bone conduction microphone  6523  are illustrated in order to show their vertical positional relationships; however, in the case of usage as shown in the drawing, these would be positioned to the rear, and therefore would not actually be visible from the front. 
     Meanwhile,  FIG. 101(C)  shows a state in which, just as shown in  FIG. 21(A) , the cartilage conduction unit  6524  is placed in contact with the ear cartilage of the tragus or the like, from the side surface side with the display unit  6505  oriented to face frontward, and the bone conduction microphone  6523  is placed against the cheekbone. Due to the small size of the ultra-compact mobile telephone  6501  of the sixty-ninth embodiment, the ultra-compact mobile telephone  6501  can be used in whichever direction is easiest to hold, either as shown above in  FIG. 101(B)  or  FIG. 101(C) . When used as shown in  FIG. 101(C) , by taking care not to grip the display screen  6505  with the fingers, soiling of the display screen  6505  due to contact of the display screen  6505  against the cheek can be prevented. By varying the angle at which the ultra-compact mobile telephone  6501  is placed against the face, the bone conduction microphone  6523  can also be positioned against the upper part of the lower jawbone while keeping the cartilage conduction unit  6524  in contact with the ear cartilage of the tragus or the like. 
     Because the ordinary mobile telephone  1601  and the ultra-compact mobile telephone  6501  each have separate phone numbers, it is possible for them to be used independently from one another. Pairing of the ordinary mobile telephone  1601  and the ultra-compact mobile telephone  6501  by short-range communication will be described next. The ordinary mobile telephone  1601 , due to its size, is not infrequently stowed inside a purse or the like when not being used, while the ultra-compact mobile telephone  6501  can be easily placed in a shirt pocket or the like, and kept in possession at all times. 
     In a first example of pairing of the two devices, the ultra-compact mobile telephone  6501 , while kept in possession in the aforedescribed manner, may be used as an incoming call vibrator for the ordinary mobile telephone  1601 . That is, when there is an incoming call to the ordinary mobile telephone  1601 , it is transferred to the ultra-compact mobile telephone  6501  through the radio waves  6585  of the short-range wireless system, whereupon the ultra-compact mobile telephone  6501  is operated as a incoming call vibrator, and can reliably alert the user of an incoming call to the ordinary mobile telephone  1601  which is being carried in a purse or the like. In the sixty-ninth embodiment, a dedicated incoming call vibrator, such as an eccentric motor, is employed as the incoming call vibrator of the ultra-compact mobile telephone  6501 ; however, as will be discussed below, it is possible for the cartilage conduction vibration unit to be vibrated to be employed concomitantly as an incoming call vibrator, as shown in the thirteenth embodiment. 
     In a second example of pairing of the two devices, the ultra-compact mobile telephone  6501 , while kept in possession in the aforedescribed manner, may be used as a handset for the ordinary mobile telephone  1601 . That is, when there is an incoming call to the ordinary mobile telephone  1601 , it is transferred to the to the ultra-compact mobile telephone  6501  through the radio waves  6585  of the short-range wireless system, whereupon after call answer operation has been performed on the ultra-compact mobile telephone  6501 , it possible for the call to take place through the cartilage conduction unit  6524  and the bone conduction microphone  6523 . In so doing, it is possible for a call to take place in a manner taking full advantage of cartilage conduction in the ordinary mobile telephone  1601 . Naturally, the ordinary mobile telephone  1601  may remain in the purse or the like at this time. 
     In a third example of pairing of the two devices, the ultra-compact mobile telephone  6501  may be used as a handset when the ordinary mobile telephone  1601  is in videoconferencing mode. In videoconferencing mode, conversation takes place with the ordinary mobile telephone  1601  held away from the face, and therefore there is a considerable distance from microphone to mouth, and also the voice of the other caller is output from a speaker situated away from the ear; thus, from an acoustic standpoint, there are numerous problems in terms of the effects of noise, loss of privacy, and the like. In contrast to this, by using the ultra-compact mobile telephone  6501  as a handset, it is possible for a call to take place in a manner that takes full advantage of cartilage conduction, with the ordinary mobile telephone  1601  in videoconferencing mode. The details of the above pairing will be discussed below. 
       FIG. 102  is a block diagram of the sixty-ninth embodiment, in which like portions are assigned the same symbols as in  FIG. 101 . As described above, the block diagram of  FIG. 102  has much in common with the block diagram of  FIG. 29 , and therefore the same reference numerals as those assigned to these parts have been assigned to the corresponding portions. In particular, the ordinary mobile telephone  1601  in  FIG. 102  has the same configuration as in  FIG. 29 . However, a portion of the configuration is omitted in  FIG. 102 . For convenience in description, the ordinary mobile telephone  1601 , which is depicted as being situated at the top in  FIG. 29 , is depicted as being situated at the bottom in  FIG. 102 . 
     When there is an incoming call to the ordinary mobile telephone  1601 , this is transferred from a short-range communication unit  1446  to a short-range communication unit  6546  by the radio waves  6585 , whereupon a controller  6539  prompts an incoming call vibrator  6525  to vibrate according to a pre-established ordinary mobile telephone incoming call alert pattern. The controller  6539  also prompts the display unit  6505  to display an alert of an incoming call to the ordinary mobile telephone  1601 . 
     When a call answer operation is input from the operating unit  6509 , this is transferred from the short-range communication unit  6546  to the short-range communication unit  1446  by the radio waves  6585 , whereupon a controller  239  of the ordinary mobile telephone  1601  initiates the call by a telephone function unit  45 . In so doing, an incoming-talk tone signal is transferred from an incoming-talk processing unit  212  of the ordinary mobile telephone  1601  to the short-range communication unit  6546  of the ultra-compact mobile telephone  6501  via the short-range communication unit  1446 . In response to this, the incoming-talk processing unit  6512  of the ultra-compact mobile telephone  6501  prompts the cartilage conduction unit  6524  to vibrate. Meanwhile, an outgoing-talk tone picked up by the bone conduction microphone  6523  is transferred from an outgoing-talk processing unit  6522  of the ultra-compact mobile telephone  6501  to the short-range communication unit  1446  of the ordinary mobile telephone  1601  via the short-range communication unit  6546 . In response, the ordinary mobile telephone  1601  transmits an outgoing-talk tone signal via a telephone communication unit  47 . 
     On the other hand, when there is an incoming call to the ultra-compact mobile telephone  6501 , the controller  6539  prompts the incoming call vibrator  6525  to vibrate according to a pre-established ultra-compact mobile telephone incoming call alert pattern. The controller  6539  also prompts the display unit  6505  to display an alert of an incoming call to the ultra-compact mobile telephone  6501 . 
     When a call answer operation is performed from the operating unit  6509 , the controller  6539  initiates the call through a telephone communication unit  6545 . In so doing, the incoming-talk processing unit  6512  prompts the cartilage conduction unit  6524  to vibrate in response to the incoming-talk signal received by the telephone communication unit  6547 . Meanwhile, on the basis of the outgoing-talk tone picked up by the bone conduction microphone  6523 , the outgoing-talk processing unit  6522  transmits an outgoing-talk tone signal via the telephone communication unit  6547 . 
     By establishing different vibration patterns for the incoming call vibrator  6525  in the above manner, it is possible to distinguish which device is being called. Additionally, the device being called is displayed on the display unit  6505  in the aforedescribed manner. Regardless of which device is called, call reception can be initiated by the same operation to the operating unit  6509  in the aforedescribed manner. As in the other embodiments, the controller  6539  operates according a program stored in a memory unit  6537 . The memory unit  6537  can temporarily store data necessary for control by the controller  6539 , as well as store measurement data and images of various kinds. A power supply unit  6548  supplies each part of the ultra-compact mobile telephone  6501  with the necessary power. 
     Seventieth Embodiment 
       FIG. 103  is a perspective view of a seventieth embodiment according to an aspect of the present invention, constituted as a mobile telephone  6601 . The mobile telephone  6601  of the seventieth embodiment has much in common with the mobile telephone system of the sixty-ninth embodiment in  FIG. 101  and  FIG. 102 , and therefore the same reference numerals are assigned to the common portions, omitting descriptions unless necessary. 
     A point of difference between the seventieth embodiment of  FIG. 103  and the sixty-ninth embodiment is that the short-range communication-enabled cartilage conduction output portion, rather than being configured as a mobile telephone capable of functioning independently, is instead configured as an outgoing-talk/incoming-talk unit that is part of the mobile telephone  6601 . In this sense, the configuration of the seventieth embodiment is shared with that of the thirteenth embodiment of  FIG. 24 . The following specific description is based on  FIG. 103 . 
     As shown in  FIG. 103(A) , a mobile telephone  6601  comprises a mobile telephone lower part  6601   a  and a mobile telephone upper part  6601   b , the two being separable. An appropriate known means, such as a planar fastener, mating structure, or the like, is utilized for joining and separation of the mobile telephone lower part  6601   a  and the mobile telephone upper part  6601   b . As in other embodiments, the mobile telephone upper part  6601   b  is furnished with a cartilage conduction unit  6626  situated in a corner of the upper portion of the mobile telephone  6601 , in the interior of which a piezoelectric bimorph element  2525  is held in cantilever fashion in a lateral/longitudinal direction. This structure is shared with the forty-second embodiment of  FIG. 65 , but with the left-right orientation reversed. On the one hand, the incoming-talk unit is furnished with a contact type bone conduction microphone  6523  situated close to the other corner of the upper part of the mobile telephone  6601 . An upper part operating unit  6609  is used to perform call answer operation and the like, while separated from the mobile telephone lower part  6601   a ; as shown in  FIG. 103(A) , when joined to the mobile telephone lower part  6601   a , operation is disabled, to prevent operation by mistake. 
     The mobile telephone  6601  is normally used in the state shown in  FIG. 103(A) , with the mobile telephone lower part  6601   a  and the mobile telephone upper part  6601   b  joined. At this time, vibration of a piezoelectric bimorph element  2525  and [operation of] an ordinary microphone  223  are enabled, while a bone conduction microphone  6523  and an ordinary earphone  213  are disabled. The way in which the device is used in this state is shared with other mobile telephone embodiments. 
     It is possible for the mobile telephone  6601  of the seventieth embodiment to be further used with the mobile telephone upper part  6601   b  separated from the mobile telephone lower part  6601   a  as shown in  FIG. 103(B) . At this time, in the mobile telephone upper part  6601   b , vibration of the piezoelectric bimorph element  2525  as well as operation for the bone conduction microphone  6523  and the upper part operating unit  6609 , are enabled. In the mobile telephone lower part  6601   a  as well, the ordinary microphone  22  and the ordinary earphone  213  are enabled. Switching of the aforedescribed bone conduction microphone  6523 , the ordinary earphone  213 , and the upper part operating unit  6609  between the enabled and disabled states takes place automatically, based on a determination as to whether the mobile telephone lower part  6601   a  and the mobile telephone upper part  6601   b  are joined or separated, as discussed below. In this way, in the state shown in  FIG. 103(B) , the mobile telephone lower part  6601   a  functions independently as an ordinary mobile telephone, while the mobile telephone upper part  6601   b  functions as a wireless outgoing-talk/incoming-talk unit for the mobile telephone lower part  6601   a.    
     The way in which the device is used in the state of  FIG. 103(B)  in the aforedescribed manner can be understood according to the sixty-ninth embodiment of  FIG. 101 . Specifically, like the ultra-compact mobile telephone  6501  of the sixty-ninth embodiment, it is possible for the separated mobile telephone upper part  6601   b  to function firstly as an incoming call vibrator; secondly, to make possible cartilage conduction calling while the mobile telephone lower part  6601   a  is kept in a purse or the like for example; and thirdly, to make possible cartilage conduction calling in videoconferencing mode with the mobile telephone lower part  6601   a  held away from the face. During cartilage conduction calling, in the same manner as with the ultra-compact mobile telephone  6501  of the sixty-ninth embodiment, the cartilage conduction unit  6626  is placed in contact with the with the ear cartilage of the tragus or the like, and the bone conduction microphone  6523  is placed against the cheekbone or lower jawbone. 
     As shown in  FIG. 103(B) , the mobile telephone upper part  6601   b  is furnished with a clip  6601   c  for clipping to the mouth of a pocket of clothing or the like. While joined to the mobile telephone lower part  6601   a , this clip  6601   c  is accommodated within a housing recess  6601   d  and is not visible from the outside, as shown in  FIG. 103(A) . The mobile telephone upper part  6601   b  is further furnished with a pair of charging contacts  6648   a  which, in the joined state, contact auxiliary charging contacts  1448   b  provided to the mobile telephone lower part  6601   a . In the joined state shown in  FIG. 103(A) , when the mobile telephone lower part  6601   a  is being charged, the mobile telephone upper part  6601   b  is charged at the same time, via contact between the auxiliary charging contacts  1448   b  and the charging contacts  6648   a . Contact versus non-contact by the auxiliary charging contacts  1448   b  and the charging contacts  6648   a  is a parameter utilized in determining whether the mobile telephone lower part  6601   a  and the mobile telephone upper part  6601   b  are joined or separated as mentioned above, and automatically switches the bone conduction microphone  6523 , the ordinary earphone  213 , and the upper part operating unit  6609  between the enabled and disabled states. 
       FIG. 104  is a block diagram of the seventieth embodiment, in which like portions are assigned the same symbols as in  FIG. 102 .  FIG. 104  has much in common with the block diagram of the sixty-ninth embodiment of  FIG. 102 , and therefore the same reference numerals as those assigned to these parts have been assigned to the corresponding portions. 
     A first point of difference between the mobile telephone upper part  6601   b  of  FIG. 104  and the ultra-compact mobile telephone  6501  of  FIG. 102  resides in a feature whereby a power supply unit  6648  is charged from the charging contacts  1448   a . A second point resides in a feature of providing the upper part operating unit  6609 , which transmits to a controller  6638  a call answer operation during separation in the aforedescribed manner. On the basis of the state of the charging contacts  6648   a , the controller  6638  determines whether a contact state or a non-contact state exists, and in a state in which the contact state is determined to exist, the controller  6639  disables the operating unit  6609 , and does not accept operations therefrom. A third point resides in a feature whereby the mobile telephone upper part  6601   b  is not constituted as an independently functioning telephone function unit, but rather serves as an outgoing-talk/incoming-talk unit  6645  for the mobile telephone upper part  6601   b . A fourth point resides in a feature whereby, in a state like that described above, in which the charging contacts  6648   a  have been determined to be in the contact state, the controller  6639  enables the bone conduction microphone  6523  of the outgoing-talk/incoming-talk unit  6645 . 
     A first point of difference between the mobile telephone lower part  6601   a  of FIG.  104  and the ordinary mobile telephone  1601  of  FIG. 102  resides a feature whereby, when the power supply unit  1448  is charged by an external charger via the main charging contacts  1448   a , a portion thereof can be supplied to the charging contacts  6648   a  of the mobile telephone upper part  6601   b  via the auxiliary charging contacts  1448   b . A second point resides a feature whereby, when the auxiliary charging contacts  1448   b  are determined to be in the contact state, the controller  239  enables the ordinary earphone  213  of the outgoing-talk/incoming-talk unit  45 . 
     Seventy-First Embodiment 
       FIG. 105  is a perspective view and a cross sectional view of a seventy-first embodiment according to an aspect of the present invention, constituted as a mobile telephone  6701 . The mobile telephone  6701  of the seventy-first embodiment has much in common with the mobile telephone  6601  of the seventieth embodiment in  FIG. 103  and  FIG. 104 , and therefore the same reference numerals are assigned to the common portions, omitting descriptions unless necessary. 
     A main difference between the seventy-first embodiment of  FIG. 105  and the seventieth embodiment is a structure in which the fact that the mobile telephone is separable into an upper part and a lower part is utilized to largely prevent vibration of a cartilage conduction unit furnished in the upper part from being transmitted to the lower part when the two are joined. The following specific description is based on  FIG. 105 . 
     As shown in  FIG. 105(A) , the mobile telephone  6701  of the seventy-first embodiment, like the seventieth embodiment, comprises a mobile telephone lower part  6701   a  and a mobile telephone upper part  6701   b , the two being separable. In the mobile telephone upper part  6701   b , the mobile telephone  6701  upper part is furnished with a hard left-ear cartilage conduction unit  6726  in the left corner of the upper part of the mobile telephone  6701 , and in the interior thereof a piezoelectric bimorph element  2525  is held in cantilever fashion in a lateral/longitudinal direction. Further, the mobile telephone upper part  6701   b  is furnished with a hard right-ear cartilage conduction unit  6724  in the right corner of the upper part of the mobile telephone  6701  upper part. The left-ear cartilage conduction unit  6726  and the right-ear cartilage conduction unit  6724  are integrally linked by a hard linking unit of the same material, so that vibration of the piezoelectric bimorph element  2525  received by the left-ear cartilage conduction unit  6726  is transmitted to the right-ear cartilage conduction unit  6724  as well. In this sense, the seventy-first embodiment has aspects in common with the sixty-fourth to sixty-seventh embodiments in  FIG. 96  to  FIG. 99 . While not depicted in  FIG. 105  in order to avoid complexity, the linking unit for linking the left-ear cartilage conduction unit  6726  and the right-ear cartilage conduction unit  6724  can be one for which the structure of the linking units  6027 ,  6127 ,  6227 , and  6327  in  FIG. 96  to  FIG. 99 , or an analogous structure, is adopted, as appropriate. The mobile telephone upper part  6701   b  of the seventy-first embodiment is not furnished with a bone conduction mic. 
     In the seventy-first embodiment, as shown in  FIG. 105(A) , transmission of vibration of the piezoelectric bimorph element  2525  of the mobile telephone upper part  6701   b  to the mobile telephone lower part  6701   a  is largely prevented by anchoring an elastic body  6765  to the upper end of the mobile telephone lower part  6701   a . The significance of the elastic body  6765  is comparable to that of the elastic bodies  6065 ,  6165 ,  6265 , and  6365  in the sixty-fourth to sixty-seventh embodiments of  FIG. 96  to  FIG. 99 . In the case of the seventy-first embodiment, in view of the fact that the one side of the joined section is made up by the elastic body  6765 , it would be possible to utilize the elasticity thereof to constitute a planar fastener. For example, as shown in fragmentary cross sectional view in  FIG. 105(B) , the joining face on the mobile telephone upper part  6701   b  side may be furnished with a plurality of fungiform protrusions  6701   c , while the surface on the opposing elastic body  6765  side may be furnished with a plurality of small openings  6765   a  at corresponding locations. The diameter of the openings  6765   a  is set to one smaller than the head section of the fungiform protrusions  6701   c , but larger than the root section. By means of such a configuration, the mobile telephone upper part  6701   b  and the elastic body  6765  can be joined through respective fitting of the fungiform protrusions  6701   c  into the openings  6765   a  in opposition to the elasticity of the elastic body  6765 . The planar fastener structure shown in  FIG. 105(B)  can in principle be utilized for anchoring the elastic body  6765  and the mobile telephone lower part  6701   a  as well. In this case, the heads of the fungiform protrusions  6701   c  to be furnished to the upper surface of the mobile telephone lower part  6701   a  would not be smoothly spherical in shape as in  FIG. 105(B) , but instead, for example, a sharp triangular shape, to provide a so-called “fixed” structure which, once driven into the openings of the elastic body  6765 , will not become dislodged. 
       FIG. 105(C)  shows a state in which the mobile telephone upper part  6701   b  is separated from the mobile telephone lower part  6701   a . From the drawing it is clear that the auxiliary charging contacts  1448   b  are furnished to the surface of the elastic body  6765 . In order to avoid complexity, in  FIG. 105(C) , the fungiform protrusions  6701   c  and the openings  6765   a  shown in  FIG. 105(B)  have been omitted from the illustration. In the seventy-first embodiment, when the mobile telephone upper part  6701   b  has been separated, to listen to a call, either the right-ear cartilage conduction unit  6724  or the left-ear cartilage conduction unit  6726  is placed in contact with the ear cartilage, while to speak, the ordinary microphone  223  of the mobile telephone lower part  6701   a  is used, just as in the joined state of  FIG. 105(A) . For videoconferencing use, the ordinary microphone  223  is used while placed in videoconferencing mode. Neither the right-ear cartilage conduction unit  6724  nor the left-ear cartilage conduction unit  6726  is designed for exclusive use in the right ear or the left ear, and therefore can be placed in contact with any ear cartilage. Moreover, both of the cartilage conduction units could be utilized instead of just one, for use while placed in contact with cartilage at two locations. 
       FIG. 106  is a block diagram of the seventy-first embodiment, in which like portions have been assigned the same symbols as in  FIG. 105 . The block diagram of  FIG. 106  has much in common with the block diagram of the seventieth embodiment in  FIG. 104 , and therefore the same reference numerals as those assigned to these parts have been assigned to the corresponding portions, and descriptions omitted.  FIG. 106  differs from  FIG. 104  in that the outgoing-talk processing unit and the bone conduction microphone are omitted. 
     The various features shown in the embodiments of the present invention are not necessarily unique to the individual embodiments in which they appear, and insofar as it is possible to utilize the advantages thereof, the features of the respective embodiments may be utilized in modified form, or utilized in combination, as appropriate. For example, the bone conduction microphone in the sixty-ninth to seventy-first embodiments may instead be configured as an ordinary microphone for picking up air-conducted sound. In the seventieth embodiment, the bone conduction microphone may be omitted, as in the seventy-first embodiment. Conversely, it would be possible to adopt a bone conduction microphone in the seventy-first embodiment. At this time, it would be preferable to situate the bone conduction microphone in the center of the mobile telephone upper part  6710   b  between the right cartilage conduction unit  6724  and the left cartilage conduction unit  6726 . In this case, because the cartilage conduction units and the bone conduction microphone are close together, a method of use in which the bone conduction microphone is placed against to bone behind the ear, and the cartilage conduction units are placed against the back side of the ear cartilage, as in the twentieth embodiment of  FIG. 33  and the twenty-fourth embodiment of  FIG. 37 , would be possible as well. 
     The cartilage conduction units in the sixty-ninth to seventy-first embodiments are configured using piezoelectric bimorph elements as the cartilage conduction vibration sources, but there is no limitation to this, and electromagnetic vibrators like those shown in other aforedescribed embodiments may be adopted as the cartilage conduction vibration sources. In the seventieth embodiment, the cartilage conduction vibration source is supported at one corner of the mobile telephone upper part, while the bone conduction microphone is situated at the other; however, in a case in which cartilage conduction vibration sources for the right ear and the left ear, respectively, are furnished at both corners of the mobile telephone upper part, it would be preferable to situate the bone conduction microphone in the center of the mobile telephone upper part between the pair of cartilage conduction vibration sources. 
     Further, the means for charging the mobile telephone upper part from the mobile telephone lower part in the seventieth embodiment or seventy-first embodiment is not limited to the electrical contacts shown in these embodiments, and may instead be configured to involve contactless charging through electromagnetic induction, for example. 
     In the seventy-first embodiment, the elastic body  6765  is anchored to the mobile telephone lower part  6701   a  side, with the mobile telephone upper part  6701   b  being detachably attached to the elastic body  6765 ; however, there is no limitation to this particular implementation. For example, in an arrangement opposite that of the seventy-first embodiment, it would be possible to configure the elastic body  6765  to be anchored to the mobile telephone upper part  6701   b  side, with the mobile telephone lower part  6701   a  being detachably attached to the elastic body  6765 . 
     Seventy-Second Embodiment 
       FIG. 107  is a block diagram relating to a seventy-second embodiment according to an aspect of the present invention, configured as a mobile telephone  6801 . Like the fifty-seventh embodiment of  FIG. 87 , in the seventy-second embodiment, the drive circuit for a piezoelectric bimorph element  5325  serving as the cartilage conduction vibration source is configured as a single-chip integrated power management IC  5303 , together with a power management circuit for supplying power to each of the parts of the mobile telephone  6801 . The block diagram of  FIG. 107  has much in common with the block diagram of  FIG. 87 , and therefore the same reference numerals are assigned to like parts, and descriptions are omitted. In the mobile telephone  6801  of the seventy-second embodiment, the cartilage conduction units are not separable as in the seventieth embodiment and the seventy-first embodiment; instead, as in the sixty-fifth embodiment of  FIG. 97  for example, the cartilage conduction units  6124 ,  6126  are anchored to the mobile telephone body, and the piezoelectric bimorph element or other cartilage conduction vibration source  2525  are held thereby. Consequently, during videoconferencing, the cartilage conduction unit is held away from the ear, and instead air-conducted sound is emitted from a videoconferencing speaker  5351 . 
     The seventy-second embodiment of  FIG. 107  and the fifty-seventh embodiment of  FIG. 87  differ in terms of control of the power supply to a charge pump circuit  5354 , and in control associated therewith. Set forth in specific terms, the charge pump circuit  5354  is connected, via a switch circuit  5354   a , to a power management circuit  5353 , the power supply being controlled through on/off switching of the switch circuit  5354   a  by a controller  5321 . Specifically, supply of power to the charge pump circuit  5354  is initiated by turning on the switch circuit  5354   a  in response to an incoming call signal or a call request signal, and is halted by turning off the switch circuit  5354   a  in response to call disconnect operation. In interlocking fashion with switching off of the switch circuit  5354   a , the controller  5321  also halts a pair of phase inversion clocks (3) which are supplied to the charge pump circuit  5354  by the controller  5321 . 
     During on/off switching of the charge pump circuit  5354 , the voltage becomes unstable in transient fashion, and this causes popping sounds to be generated by the piezoelectric bimorph element  5325 . In order to prevent this, a muting circuit  5340   a  is inserted between an amplifier  5340  and the piezoelectric bimorph element  5325 . Then, under the control of the controller  5321 , the muting circuit  5340   a  is turned on for a predetermined time interval prior to on/off switching of the charge pump circuit  5354 , so that voltage fluctuations of the amp  5340   a  are not transmitted to the piezoelectric bimorph element  5325 . The muting circuit  5340   a  stays on for a somewhat longer time interval than the time interval needed for the charge pump circuit  5354  to stabilize, then unmutes by turning off at a timing at which the voltage can be expected to have stabilized. Through such on/off switching of the muting circuit  5340   a , it is possible to prevent generation of popping sounds during on/off switching of the charge pump circuit  5354 , as well as to drive the piezoelectric bimorph element  5325  once the charge pump circuit  5354  has reached a power supply state with no popping sounds. 
       FIG. 108  is timing charts showing power supply control to the charge pump circuit  5354  in the seventy-second embodiment.  FIG. 108(A)  is a timing chart in a case in which a telephone receives an incoming call; firstly, at timing t 1  at which an incoming call is received in the standby state, the muting circuit  5340   a  switches on. Upon entering a state at timing t 2 , in which the piezoelectric bimorph element  5325  is thereby unaffected by voltage fluctuations of the amp  5340 , the switch circuit  5354   a  switches on, and supply of power from the power management circuit  5353  to the charge pump circuit  5354  is initiated, initiating supply of phase inversion clocks (3) from the controller  5321  as well. As shown conceptually by diagonal lines in  FIG. 108(A) , from initial startup until reaching a predetermined voltage, the output voltage of the charge pump circuit  5354  is not stable during a transient period. The muting circuit  5340   a  goes on and maintains a muted state during a time slot sufficient to cover this transient period, then unmutes by turning off at a timing t 3  at which the voltage can be expected to have stabilized. In so doing, regardless of when a call answer operation is performed, the piezoelectric bimorph element  5325  will be in a state of readiness that enables cartilage conduction calling. The reason for prompting such an operation at the point in time that an incoming call signal is received is so that the piezoelectric bimorph element  5325  reliably enters the activated state when the call is initiated, as there are conceivably cases in which the call answer operation is performed very rapidly. 
     Next, the call is initiated at arbitrary timing t 4  once a call answer operation is performed. Then, when a call disconnect operation is made at timing t 5 , in response to this, firstly, the muting circuit  5340   a  turns on. Then, upon entering a state at timing t 6 , in which the piezoelectric bimorph element  5325  will not be affected by voltage fluctuations of the amp  5340 , the switch circuit  5354   a  switches off, power supply from the power management circuit  5353  to the charge pump circuit  5354  is interrupted, and supply of phase inversion clocks (3) from the controller  5321  is halted as well. As shown conceptually by diagonal lines in  FIG. 108(A) , during halting of function of the charge pump circuit  5354 , the output voltage is not stable during a transient period. The muting circuit  5430   a  stays on during a time slot sufficient to cover this transient period, then turns off at a timing t 7  at which stability can be expected to have halted. In so doing, generation of popping sounds from the piezoelectric bimorph element  5325  can be prevented, even when the charge pump circuit  5354  turns off. 
       FIG. 108(B)  is a timing chart in the case of placing a telephone call. At timing t 1 , a contact input operation is initiated by selecting phonebook data or through manual input. At this point in time, as it is not certain whether a call will actually be placed, the power supply to the charge pump circuit  5354  is suspended. At arbitrary timing t 2 , at which the contact input operation is completed and a call request operation is performed, in response to this, firstly, the muting circuit  5340   a  turns on. Then, in the same manner as in  FIG. 108(A) , upon entering a state at timing t 3  in which the piezoelectric bimorph element  5325  will not be affected by voltage fluctuations of the amp  5340 , the switch circuit  5354   a  switches on, and power supply from the power management circuit  5353  to the charge pump circuit  5354  is initiated, initiating supply of phase inversion clocks (3) from the controller  5321  as well. In the same manner as in  FIG. 108(A) , the muting circuit  5430   a  turns off at timing t 4 , at which the voltage can be expected to have stabilized. The call is then initiated at timing t 5 , by a call answer operation performed by the callee in response to the call request. Due to the sufficient length of time until a call answer operation is performed by the callee in response to the call request, upon entering the startup process of the pump charge circuit  5354  in response to the call request operation, the piezoelectric bimorph element  5325  can reliably be anticipated to be in the activated state in reliable fashion at the time of initiation of the call, as shown in  FIG. 108(B) . Even when the piezoelectric bimorph element  5325  enters the activated state due to a call request operation, the call is not initiated unless the callee performs a call answer operation; however, because it is conceivable that call setup would not take place in time if the piezoelectric bimorph element  5325  does not start up until after the callee performs a call answer operation, the piezoelectric bimorph element  5325  is placed in the activated state without waiting for the call to be set up. 
     Next, when a call disconnection operation is performed at timing t 6 , in response to this, firstly, the muting circuit  5340   a  turns on, in the same manner as in  FIG. 108(A) . Then, upon entering a state at timing t 7 , in which the piezoelectric bimorph element  5325  will not be affected by voltage fluctuations of the amp  5340 , the switch circuit  5354   a  switches off, supply of power from the power management circuit  5353  to the charge pump circuit  5354  is interrupted, and supply of phase inversion clocks (3) from the controller  5321  is halted as well. In the same manner as in  FIG. 108(A) , the muting circuit  5430   a  stays on during a time slot sufficient to cover the transient period when functioning of the charge pump circuit  5354  halts, then turns off at a timing t 8  at which stability can be expected to have halted. In so doing, in the same manner as in  FIG. 108(A) , generation of popping sounds or the like from the piezoelectric bimorph element  5325  can be prevented, even when the charge pump circuit  5354  turns off. As described above, there may be cases in which the callee fails to perform a call answer operation in response to the call request operation, and at such times a disconnect operation is performed without setting up the call. In this case,  FIG. 108(B)  may be understood to mean that no call state exists from t 5  to t 6  which are depicted between the call request operation at t 2  and the disconnect operation at t 6 . 
       FIG. 109  is a flowchart of operation of an application processor  5339  in the seventy-second embodiment shown in  FIG. 107  and  FIG. 108 . The flow in  FIG. 109  primarily describes the functions of power supply control to the charge pump circuit  5354 , and therefore operations centered on related functions have been extracted for illustration. Consequently, in the seventy-second embodiment, there are other operations of the application processor  5339 , such as typical functions of mobile telephones and like, which are not represented in the flow of  FIG. 109 . The flow of  FIG. 109  starts when the main power source of the mobile telephone  6801  is turned on, and in Step S 302 , initial startup and a function check of each unit are performed, as well as initiating screen display on a display unit  5305 . Next, in Step S 304 , supply of power to the charge pump circuit  5354  turns off, and the routine advances to Step S 306 . In this manner, the mobile telephone  6801  of the seventy-second embodiment firstly turns off the supply of power to the charge pump circuit  5354  and starts up. 
     In Step  306 , a check for an incoming call is performed, and in the event there is an incoming call, the routine advances to Step S 308 , and checks whether or not there is a videoconference. In event there is no videoconference, the routine advances to Step S 310 , and the muting circuit  5340   a  is instructed to initiate muting for a predetermined time interval. Next, advancing to Step S 312 , an instruction to turn on the charge pump circuit  5354  is issued, and the routine advances to Step S 314 . To facilitate understanding, Step S 310  and Step S 312  are described as being functions of the application processor  5339 ; however, in actual practice, sequence control to mute for a predetermined time interval and to power on the charge pump circuit  5354  is delegated to the integrated power management IC  5303 . In this case, in Step S 310 , an instruction to turn on the charge pump circuit  5354  is simply issued from the application processor  5339  to the controller  5321 , and the routine advances to Step S 314 . 
     In Step S 314 , a check is made to determine whether or not a call answer operation has been performed, and in the event that no operation is detected, the routine returns to Step S 306 , and repeats Step S 306  to Step S 312  for as long as the incoming call is ongoing. In this case, in the event that the muting for a predetermined time interval and powering on of the charge pump circuit  5354  have been completed, Step S 310  and Step S 312  are omitted. On the other hand, when a call answer operation has been detected in Step S 314 , the routine advances to the call process of Step S 328 . 
     On the other hand, in the case that no incoming call is detected in Step S 306 , the routine advances to Step S 316 . When an incoming videoconference is detected in Step S 308 , the routine advances to Step S 318 , performs videoconferencing processes, and advances to Step S 316 . The videoconferencing processes of Step S 318  correspond to processes lasting from initiation of videoconferencing to calling and disconnection thereof. Consequently, advance from Step S 318  to Step S 316  takes place when the videoconference is disconnected. The videoconferencing processes include a process for emitting the voice of the other caller from an air-conduction speaker during the call. In this way, in cases in which a videoconference is detected, the telephone is used with the piezoelectric bimorph element  5325  held away from the ear cartilage, and therefore from the outset, no power is fed to the charge pump circuit  5354 . 
     In Step S 316 , a check is made to determine whether or not a contact input operation has been performed, and in the event that an input operation has been performed, the routine proceeds to Step S 320 , and checks whether a call request operation has been performed. In the event that a call request operation has been performed, the routine advances to Step S 322 , and checks whether a videoconference request operation has been performed. In the event that there is no videoconference request, the routine advances to Step S 324 , and the muting circuit  5340   a  is instructed to initiate muting for a predetermined time interval. Next, advancing to Step S 326 , an instruction to turn on the charge pump circuit  5354  is issued, and the routine advances to Step S 328 . As in Step S 310  and Step S 312 , sequence control in relation to Step S 324  and Step S 326  is delegated to the controller  5321  of the integrated power management IC  5303 . 
     On the other hand, in the event that contact input is not detected in Step S 316 , or in a case in which no call request operation has been detected in Step S 320 , the routine advances to Step S 336 . When an incoming videoconference is detected in Step S 322 , the routine advances to Step S 338 , performs videoconferencing processes, and advances to Step S 336 . The case of videoconferencing processes of Step S 338  corresponds to the process of awaiting a call answer operation by the callee, and processes based on a call answer operation, lasting from initiation of videoconferencing to calling and disconnection thereof. Consequently, advance from Step S 338  to Step S 336  occurs when the videoconference is disconnected, or when a call request is disconnected in the absence of a call answer operation by the callee. As in Step S 318 , the videoconferencing processes in Step S 338  include emitting the voice of the other caller from an air-conduction speaker during the call, and from the outset, no power is fed to the charge pump circuit  5354 . 
     In Step S 328 , call processes based on a call answer operation in Step S 314  or a call request operation in Step S 320  are performed. In more specific terms, the call processes in Step S 328  refer, in the case of a routine via Step S 314 , to functions taking place during the call, and include management to advance to Step S 330  at each of predetermined time intervals and check whether there has been a disconnect operation. Step S 328  and Step S 330  are repeated in this fashion in the absence of a disconnect operation. On the other hand, in the case of a routine via a call request operation made in Step S 320 , the processes refer to the function of awaiting a call answer operation by callee, and functions taking place during the call after a call answer operation. In this case as well, the routine advances to Step S 330  at each of predetermined time intervals, and checks whether there has been a disconnect operation. At this time, when a disconnect operation has been detected in Step S 330  in the absence of a call answer process by the callee, as a result, only the callee call answer operation wait function will have taken place in Step S 328 . 
     Once a disconnect operation is detected in Step S 330 , the routine advances to Step S 322 , and the muting circuit  5430   a  is instructed to initiate muting for a predetermined time interval. Next, the routine advances to Step S 334 , the charge pump circuit  5354  is instructed to turn off, and the routine advances to Step S 336 . As in Step S 310  and Step S 312 , sequence control in relation to Step S 332  and Step S 334  is delegated to the controller  5321  of the integrated power management IC  5303 . 
     In Step S 336 , a check is performed to determine whether or not the main power source has been turned off, and in the event the power is not detected to be off, the routine returns to Step S 306 , and thereafter repeats the aforedescribed series of flows until detected that the main power source has been turned off. Once detected that the main power source has been turned off, the flow terminates. 
     The various features shown in the embodiments of the present invention are not necessarily unique to the individual embodiments in which they appear, and insofar as it is possible to utilize the advantages thereof, the features of the respective embodiments may be utilized in modified form, or utilized in combination, as appropriate. For example, in the seventy-second embodiment, a charge pump circuit is adopted as the voltage booster circuit for driving the piezoelectric bimorph elements, and while this is a suitable selection, there is no limitation to this, and employment of other voltage booster circuit, as appropriate, is not precluded. 
     Seventy-Third Embodiment 
       FIG. 110  is a perspective view relating to a seventy-third embodiment according to an aspect of the present invention, configured as a mobile telephone  6901 . In terms of external appearance, the seventy-third embodiment has much in common with the fifty-fifth embodiment shown in  FIG. 83 , and in terms of internal configuration and function has much in common with the fourth embodiment shown in  FIG. 8  and  FIG. 10 ; therefore, the common portions are assigned the same reference numerals as in these embodiments, and discussions are omitted. 
     A point of difference between the seventy-third embodiment of  FIG. 110  and the fourth embodiment of  FIG. 55  is that, as shown in perspective view from the front in  FIG. 110  (A), the videoconferencing in-camera  6917  is situated in proximity to the lower right corner of the mobile telephone  6901 . In the seventy-third embodiment, there is no extra available space in the upper part of the mobile telephone  6901 , due to the placement of cartilage conduction units  5124  and  5126  and internal cartilage conduction vibration sources for transmitting vibration thereto. Therefore, in the seventy-third embodiment, the videoconferencing in-camera  6917  is situated in proximity to the lower right corner of the mobile telephone  6901 , on the opposite side from the cartilage conduction units  5124  and  5126 , with a display screen  6905  therebetween. 
     The seventy-third embodiment is furnished with a display lamp  6965  comprising an LED or the like, for notifying of incoming calls or emails, and the videoconferencing in-camera  6917  is situated in proximity to this display lamp  6965 . By prompting the display lamp  6965  to blink randomly during videoconferencing, the user&#39;s line of sight can be directed towards the videoconferencing in-camera  6917 . In so doing, the line of sight of the user&#39;s face displayed on the display unit of the other caller&#39;s video phone will be oriented squarely frontward. This feature will be further discussed below.  FIG. 110(B)  is a rear perspective view of the mobile telephone  6901 , and shows the placement of a rear main camera  6955 . 
     As shown in  FIG. 110(C) , the mobile telephone  6901  of the seventy-third embodiment is used while held in landscape orientation with the long edges of the display screen  6905  oriented on the horizontal. Because the videoconferencing in-camera  6917  is situated in proximity to the lower right corner of the mobile telephone  6901  as seen in  FIG. 110(A) , when held in landscape orientation as shown in  FIG. 110(C) , the camera is at the upper right corner. In so doing, the videoconferencing in-camera  6917  is able to capture the user&#39;s face at a natural angle from the upper right during a videoconference. Additionally, the videoconferencing in-camera  6917  is situated such that a direction perpendicular to the long edges of the display screen  6905  is aligned with a vertical direction of a captured image as shown in  FIG. 110(C) . In cases in which the other caller&#39;s video phone is held in landscape orientation as well, the other caller&#39;s face will be displayed on the display screen  6905 . The user&#39;s own face is also displayed as shown in  FIG. 110(C) , on the display screen of the other caller&#39;s mobile telephone which is being held in landscape orientation. With regard to portrait orientation versus landscape orientation, the orientation in which the mobile telephone is held can be detected through detection of gravitational acceleration by an ordinary acceleration sensor  49 , and the orientation of an image rotated automatically by 90°; due to the seventy-third embodiment being configured in this fashion, in videoconferencing mode, the image rotation function of the acceleration sensor  49  is halted. When the other caller&#39;s mobile telephone is not being held in landscape orientation, the left and right sides of the user&#39;s own face are cropped at left and right to produce a vertically elongated image, which is displayed on the display unit of the other caller&#39;s mobile telephone. Moreover, when the other caller&#39;s mobile telephone is not being held in landscape orientation, the long edge direction of the display screen becomes the vertical direction of the image, and therefore if nothing were done, the other caller&#39;s face would be displayed in landscape orientation. Consequently, as discussed below, an image from a mobile telephone not held in landscape orientation will be automatically rotated by 90°, for display on the display screen  6905 . At this time, the other caller&#39;s face will be displayed at the center of the vertically elongated image, and therefore there is empty space in which nothing is displayed at the left and right of the display screen  6905 . This empty space can be utilized for display of data. The user&#39;s own voice is captured by a microphone  6923  of the video phone, while the other caller&#39;s voice is output from a speaker  6951 . 
     At this time, the display lamp  6965  is made to blinked randomly in the manner discussed above (for example, flashed randomly in several sets per minute, blinking on and off several times per set, for about 0.5 second each time). An ordinary videoconference is made while looking at the other caller&#39;s face on the display screen  6905 , but this means that the line of sight is not facing towards the videoconferencing in-camera  6917 . Consequently, on the other caller&#39;s screen as well, the line of sight will not be looking towards the other caller. In contrast to this, when the user&#39;s line of sight, attracted by random flickering in the aforedescribed manner, is drawn to the display lamp  6965 , his or her line of sight becomes directed towards the videoconferencing in-camera  6917  which is situated nearby, thus producing the effect that his or her line of sight is facing the other caller, on the other caller&#39;s screen. 
       FIG. 110(D)  shows a state in which the display screen  6905  is split, with the other caller&#39;s face being displayed in a right side screen  6905   a , and an image captured by the rear main camera  6955  being monitor-displayed in a left side screen  6905   b . The monitor-displayed image is transmitted to the other caller, together with the user&#39;s own face captured by the videoconferencing in-camera  6917 . In so doing, a videoconference conversation can take place while sending the other caller an image of the user&#39;s own face, together with scenery or the like currently viewed by the user. 
       FIG. 111  is perspective views showing various videoconferencing modes in the seventy-third embodiment in the aforedescribed manner.  FIG. 111(A)  is the same as  FIG. 110(D) , and shows a mode in which the other caller&#39;s face is displayed in the right side screen  6905   a , while an image captured by the rear main camera  6955  monitor-displayed in the left side screen  6905   b.    
     In contrast to this,  FIG. 111(B)  shows a mode in which the other caller&#39;s face is displayed in the right side screen  6905   a , while an image transmitted by the other caller is displayed in the left side screen  6905   b . Switching between the modes of  FIG. 111(A)  and  FIG. 111(B)  is accomplished by operation of the mobile telephones in mutual agreement with the other caller during the call. It is possible for sent and received images to be still images, not just video images. When sent or received images contain large amounts of data, during intervals that images from the rear main camera  6955  are sent and received, sending and receiving of images takes place on a time-division basis, stopping transmission of face image data to one another. 
     As will be discussed below, during transmission of a user&#39;s own face, together with scenery or the like currently viewed by the user, picture quality drops, but is it possible for images from the rear main camera  6955  and image from the videoconferencing in-camera  6917  to transmitted in synthesized form. In this case, an image containing a user&#39;s own face and scenery or the like currently viewed by the user can be transmitted to a mobile telephone that is not compatible with transmission/reception of images on two screens. 
       FIG. 111(C)  shows a state in which an image of scenery or the like transmitted by the other caller is displayed on the right side screen  6905   a , and an image from the rear main camera  6955  to be sent to the other caller is monitor-displayed on the left side screen  6905   b . In this case, landscapes or the like viewed by the callers can be exchanged with one another during a videoconference. 
       FIG. 112  is a flowchart showing videoconferencing processing in the seventy-third embodiment, and can be understood to describe the details of videoconferencing processing in Step S 36  of the fourth embodiment shown in  FIG. 10 . When videoconferencing processing starts, in Step S 342 , an advisory to the effect that the mobile telephone  6905  should be used while held in landscape orientation is displayed on the display screen  6905 . This display continues for a short while, and in parallel therewith, the flow proceeds directly to Step S 346 , and the speaker  6901  is turned on. Then, in Step S 348 , an advisory announcement to the effect that the mobile telephone  6905  should be used held in landscape orientation is made. In parallel with initiating the announcement, the flow proceeds directly to Step S 349 , and the function of auto-rotation of the image according to the orientation of the mobile telephone  6901  detected by the acceleration sensor  49  is halted. Next, proceeding to Step S 350 , a check is performed to determine whether the other caller&#39;s mobile telephone is landscape orientation-compatible. In the event that it is not landscape orientation-compatible, the flow proceeds to Step S 352 , in which the received image display is rotated by 90° so that the other caller&#39;s face appears upright in landscape orientation, then advances to Step S 354 . If the phone is one that is landscape orientation-compatible, the flow advances directly to Step S 354 . 
     In Step S 354 , the videoconferencing in-camera  6917  is turned on, and in Step S 356 , the microphone  6923  is turned on. Then, in Step S 358 , a check is performed to determine whether or not the device is in a “dual camera mode” in which both the videoconferencing in-camera  6917  and the rear main camera  6955  are used. The mode can be set manually beforehand, or changed in the course of a videoconference. In the event that the device is not in the “dual camera mode,” in Step S 360 , the rear main camera  6955  is turned off; when already off, nothing is done in this step. Next, the display screen  6905  is set to full-screen display, and image transmission/reception processing is performed in Step S 364 . This processing is the same as that for an ordinary video phone, with processing being performed in time units of procedures. 
     Once the processing of Step S 364  is finished, the routine proceeds to Step S 368 , and checks whether or not a time interval has arrived to randomly flash the display lamp  6965  on the basis of a simple random number process or the like. Upon arriving at a flash time, in Step S 370 , an instruction prompting a single set of flashes by the LED is issued in order to catch the user&#39;s attention to direct his or her line of sight towards the videoconferencing in-camera  6917 , and the routine advances to Step S 372 . When the routine has not yet arrived at a flash time, it proceeds directly to Step S 372 . On the other hand, when detected in Step S 358  that the device is in the “dual camera mode,” the routine proceeds to Step S 374  in which the rear main camera  6955  is turned on, then proceeds to the “dual camera mode” processing of Step S 376 , and when this process finishes, advances to Step S 372 . The details of the “dual camera mode” processing of Step S 376  will be discussed below. In Step S 372 , it is checked whether a videoconference disconnect operation has been performed, and in the event that no such operation has been performed, the routine returns to Step S 358 . Step S 358  to Step S 376  are repeated subsequently until a disconnect operation is performed. Mode changes can be accommodated during this repetition as well. On the other hand, in the event that a disconnect operation is detected in Step S 372 , the flow terminates, and the routine advances to Step S 38  of  FIG. 10 . 
       FIG. 113  shows the details of “dual camera mode” processing in Step S 376  of  FIG. 112 . When the flow starts, in Step S 382 , a check is performed to determine if the device is in a synthesized video mode, and when this is the case, proceeds to Step S 384 , in which the images from the videoconferencing in-camera  6917  and the rear main camera  6955  are synthesized, and an instruction to transmit synthesized video is issued in Step S 386 . Further, in Step S 388 , a full-screen display instruction is issued, in Step S 390  an instruction to display the received synthesized video is issued, and the routine advances to Step S 404 . On the other hand, in the event that the synthesized video mode has not been detected in Step S 382 , the routine advances to Step S 392 . 
     In Step S 392 , a dual screen display instruction is issued, and in Step S 394  an instruction to transmit images from the videoconferencing in-camera  6917  is issued. Further, in Step S 396 , an instruction is issued to display a received image of the other caller&#39;s face on the right side display screen  6905   a , whereupon the routine advances to Step S 398 . In Step S 398 , it is checked whether the mode is one of transmitting images from the rear main camera  6955 , and when this is the case, in Step S 400 , an instruction is issued to monitor-display images from the rear main camera  6955  on the left side display screen  6905   b , as well as to transmit the images to the other caller&#39;s mobile telephone. The routine then advances to Step S 404 . 
     On the other hand, in the case of a confirmation in Step S 398  that the device is not in a mode of transmitting images from the rear main camera  6955 , this means that the mode is one of receiving images from the other caller, and therefore the routine proceeds to Step S 402 , whereupon an instruction to display images received from the other caller&#39;s rear main camera on the left side display screen  6905   b  is issued, and the routine proceeds to Step S 404 . In Step S 404 , a check is performed to determine whether or not a time interval to randomly flash the display lamp  6965  has arrived, and upon arriving at such a flash time, in Step S 406 , an instruction to attract attention by blinking the display lamp  6965  is issued, and the routine advances to Step S 408 . When the routine has not yet arrived at a flash time, it proceeds directly to Step S 408 . The purpose is the same as in Step S 368  and Step S 370  in  FIG. 112 . 
     In Step S 408 , a check is performed to determine if a “dual camera mode” videoconference termination change has been made, and in the event that no such operation has been performed, the routine returns to Step S 382 . Step S 382  to Step S 408  are repeated subsequently until a termination operation is performed. Mode changes can be accommodated during this repetition as well. On the other hand, in the event that a termination operation is detected in Step S 408 , the flow terminates, and the routine advances to Step S 372  of  FIG. 112 . 
     Implementation of the present invention is not limited to the aforedescribed embodiments, and the various advantages of the present invention can be enjoyed in other embodiments as well. Further, these features may be interchanged or utilized in combination among various embodiments. For example, the flowcharts shown in  FIG. 112  and  FIG. 113  can be adopted in the videoconferencing processing of Step S 318  and Step S 338  of the seventy-second embodiment shown in  FIG. 109  as well. 
     Whereas conventional videoconferencing in-cameras are arranged such that a direction parallel to the long edges of the rectangular display screen  6905  coincides with a vertical direction of image capture, the videoconferencing in-camera  6917  in the aforedescribed seventy-third embodiment is arranged such that a direction perpendicular to the long edges of the rectangular display screen  6905  coincides with the vertical direction of image capture, as shown in  FIG. 110(C) . In order avoid confusion in relation to displayed image rotation stemming from this situation, in the seventy-third embodiment, once videoconferencing has been established, the displayed image auto-rotate function based on the acceleration sensor  49  performed in Step S 349  of  FIG. 112  is halted. Then, during a videoconference with another caller, an ordinary mobile telephone rotates the displayed image by 90° by performing Step S 350  and Step S 352 . However, countermeasures for preventing confusion stemming from the arrangement whereby a direction perpendicular to the long edges of the rectangular display screen  6905  coincides with the vertical direction of image capture in the videoconferencing in-camera  6917  are not limited to this. For example, a configuration whereby, utilizing the display image auto-rotate function based on the acceleration sensor  49 , the orientation of the displayed image by the auto-rotate function is corrected by 90°, on the basis of whether or not information indicating that the vertical direction of the videoconferencing in-camera  6917  diverges by 90° from normal is available, would also be acceptable. Further, a configuration whereby, in the same manner as a conventional device, the videoconferencing in-camera  6917  is arranged such that the direction parallel to the long edges of the rectangular display screen  6905  coincides with the vertical direction of image capture, and during videoconferencing, the display image is always rotated 90° by the auto-rotate function, would also be acceptable. 
     Additionally, in cases in which the vibration source of the cartilage conduction unit  5124  in the seventy-third embodiment is configured as a piezoelectric bimorph element, it is possible for the element to also function as an impact sensor in the manner described in the fourth embodiment, and therefore a configuration whereby switching between main camera image transmission mode and reception mode during a videoconference is performed by detecting the impact produced by lightly tapping the cartilage conduction unit  5124  with the index finger, with the mobile telephone  6901  held sideways. Further, in the thirteenth embodiment and the seventeenth embodiment, the cartilage conduction unit functions as an incoming call vibrator, and it is possible for the cartilage conduction unit  5124  or  5126  of the seventy-third embodiment to likewise be concomitantly employed as a vibrating unit for notification purposes. For example, the cartilage conduction unit  5124  or  5126  could be configured to produce predetermined vibration every minute, thereby transmitting passage of time during a videoconference, to a hand holding the mobile telephone  6901  sideways. 
     Seventy-Fourth Embodiment 
       FIG. 114  is a block diagram relating to a seventy-fourth embodiment according to an aspect of the present invention, configured as a cartilage conduction vibration source device for a mobile telephone. The seventy-fourth embodiment has, as its foundation, considerations based on the structure of the ear and on actual measurement data for the mobile telephone reviewed in  FIG. 79  and  FIG. 80 , as well as a review of the frequency characteristic correction unit (the cartilage conduction equalizer  5038  and the cartilage conduction low-pass filter  5040 ) in the fifty-fourth embodiment of  FIG. 82  configured on the basis thereof. Configuration-wise, it relates to functions corresponding to the analog front end unit  5336  of the integrated power management IC  5303 , the cartilage conduction acoustic signal processing unit  5338 , the charge pump circuit  5354 , and the amp  5340  in the fifty-seventh embodiment of  FIG. 87  and the seventy-second embodiment of  FIG. 107 . Consequently, the details of the significance of this configuration may be understood through reference to the disclosures, and description is omitted where redundant. 
     The seventy-fourth embodiment of  FIG. 114  provides a cartilage conduction vibration source device controllable by an application processor  7039  and a power management circuit  7053  in an ordinary mobile telephone, and specifically is configured as a piezoelectric bimorph element  7013  (illustrated as an equivalent circuit, together with a capacitor) as the cartilage conduction vibration source, and a driver circuit  7003  therefor. The driver circuit is basically a drive amp for the piezoelectric bimorph element  7013 , and incorporates therein an analog acoustic processing circuit  7038  serving as the frequency characteristic correction unit. Driving at suitable frequency characteristics, with the piezoelectric bimorph element  7013  as the cartilage conduction vibration source, is possible simply by connecting an audio output from the ordinary application processor  7039 . 
     Stated in more specific terms, an analog sound signal output by a differential from a speaker analog output unit  7039   a  of the application processor  7039  is input to an analog input amp  7036 , and is output through the analog acoustic processing circuit  7038  to analog output amps  7040   a  and  7040   b , then used for differential driving of the piezoelectric bimorph element  7013 . The driver circuit  7003  incorporates a voltage booster circuit  7054  (in specific terms, one comprising a charge pump circuit) for the analog output amps  7040   a  and  7040   b , whereby driving is possible by inputting, as a power source voltage from a power input unit  7054   a , an output voltage (2.7-5.5 V) of the ordinary power management circuit  7053 . 
     The analog acoustic processing circuit  7038  has functions comparable to the cartilage conduction equalizer  5038  and the cartilage conduction low-pass filter  5040  in the fifty-fourth embodiment of  FIG. 82 , and also functions as a startup sequence circuit for automatically reducing clicking noises and popping noises. In some cases, correction of frequency characteristics by the cartilage conduction equalizer  5038  and the cartilage conduction low-pass filter  5040  may be established across the board, while in other cases, custom settings or adjustments are possible according to factors such as the age of the ear. 
     Seventy-Fifth Embodiment 
       FIG. 115  is a block diagram relating to a seventy-fifth embodiment according to an aspect of the present invention. The seventy-fifth embodiment, like the seventy-fourth embodiment, is configured as a cartilage conduction vibration source device for a mobile telephone, and has much in common therewith; therefore, the same reference numerals are assigned to comparable configurations, omitting descriptions thereof. Whereas the seventy-fourth embodiment of  FIG. 114  is configured as an all-analog circuit, the seventy-fifth embodiment of  FIG. 115  differs therefrom in that a digital acoustic processing circuit  7138  is adopted in the driver circuit  7103 . 
     However, as in the seventy-fourth embodiment, the input and output of the driver circuit  7103  are analog, and input analog signal is converted to a digital signal by a DA conversion circuit  7138   a  and input to the digital acoustic processing circuit  7138 , while a digital output of the digital acoustic processing circuit  7138  is converted to an analog signal by a DA conversion circuit  7138   b , and transferred to the analog output amps  7040   a  and  7040   b . The input to the driver circuit  7103  is not a differential input; instead, an analog sound signal from an analog output  7039   b  of the application processor  7039  is input. The issue of whether input takes place by differential signaling or not is not a respective characterizing feature of the seventy-fourth and seventy-fifth embodiments, and therefore an appropriate configuration may be selected, according to the circumstances of connection to the application processor  7039 . 
     Seventh-Sixth Embodiment 
       FIG. 116  is a block diagram relating to a seventy-sixth embodiment according to an aspect of the present invention. The seventy-sixth embodiment, like the seventy-fourth and seventy-fifth embodiments, is configured as a cartilage conduction vibration source device for a mobile telephone, and has much in common therewith; therefore, the same reference numerals are assigned to comparable configurations, omitting descriptions thereof. A point of difference between the seventy-sixth embodiment of  FIG. 116  and the seventy-fourth or seventy-fifth embodiment is that a digital sound signal from a digital output unit ( 12 S)  7039   c  of the application processor  7039  is input to a driver circuit  7203 . Then, in the same manner as in the seventy-fifth embodiment, a digital sound signal from the application processor  7038  is directly input to the digital acoustic processing circuit  7138  by an input unit  7236 . 
     Digital output from the digital acoustic processing circuit  7138  is converted by a DA conversion circuit  7138   c  to an analog signal, which is transferred to an output amp  7240   a , as well as being inverted by an analog output amp  7240   b , and employed for differential driving of the piezoelectric bimorph element  7013 . The issue of whether the analog output of the DA conversion circuit  7138   c  is inverted by the analog output amp  7240   b  as in the seventy-sixth embodiment, or whether two analog signals inverted by the DA conversion circuit  7138   b  itself are output as in the seventy-fifth embodiment, is not a respective characterizing feature of the seventy-fifth and seventy-sixth embodiments, and any appropriate configuration may be selected. 
     Seventy-Seventh Embodiment 
       FIG. 117  is a block diagram relating to a seventy-seventh embodiment according to an aspect of the present invention. The seventy-seventh embodiment, like the seventy-fourth to seventy-sixth embodiments, is configured as a cartilage conduction vibration source device for a mobile telephone, and has much in common therewith; therefore, the same reference numerals are assigned to comparable configurations, omitting descriptions thereof. A point of difference between the seventy-seventh embodiment of  FIG. 117  and the seventy-fourth to seventy-sixth embodiments is that a driver circuit  7303  has an all-digital configuration. Consequently, a digital sound signal output from the digital output unit ( 12 S)  7039   c  of the application processor  7039  is input directly to the digital acoustic processing circuit  7138  by the input unit  7236 , and digital output from the digital acoustic processing circuit  7138  is transferred to class-D power amps  7340   a  and  7340   b.    
     A vibration source module  7313  is provided in combination with a driver circuit  7303  for outputting a digital drive signal as in the seventy-seventh embodiment, and is configured as a piezoelectric bimorph element module incorporating a low-pass filter (in specific terms, a choke coil for smoothing PWM signals)  7313   a  for differential PWM signals output from the class-D power amps  7340   a  and  7340   b . In so doing, even in cases in which the all-digital driver circuit  7303  has been adopted, by providing this in combination with the vibration source module  7313 , there can be provided a cartilage conduction vibration source device controllable by the application processor  7039  and the power management circuit  7053  in an ordinary mobile telephone, without the burden of having to provide an external smoothing choke coil with matched characteristics, or the like. 
     In the forty-fourth embodiment of  FIG. 67 , there is shown a structure in which the piezoelectric bimorph element and the circuit form a resin package which is held as an integrated vibration unit, and the choke coil  7313   a  of the seventy-seventh embodiment of  FIG. 117  can be thought of as the most simple example of a circuit that is integrated with a piezoelectric bimorph element into a resin package, as in the forty-fourth embodiment. Consequently, the shape and holding structure reviewed in the forty-fourth embodiment of  FIG. 67  could be adopted for the vibration source module  7313  of the seventy-seventh embodiment. 
     In the above manner, the seventy-fourth to seventy-seventh embodiments can provide a cartilage conduction vibration source device controllable by the application processor  7039  and the power management circuit  7053  in an ordinary mobile telephone, without the burden of adjustment and review to achieve good cartilage conduction, even in the absence of any knowledge or information about cartilage conduction. The specific configuration is not limited to those of the seventy-fourth to seventy-seventh embodiments, and provided that the advantages thereof can be enjoyed, it is possible to make appropriate changes to the combination of circuit components. The present invention does not just feature configuration as a single driver circuit as in the seventy-fourth to seventy-seventh embodiments, and configurations involving incorporation as part of a large-scale circuit, such as the integrated power management IC  5303  in the fifty-seventh embodiment of  FIG. 87  or the seventy-second embodiment of  FIG. 107 , are also acceptable. 
     Seventy-Eighth Embodiment 
       FIG. 118  is a cross sectional view relating to a seventy-eighth embodiment according to an aspect of the present invention, and is configured as a mobile telephone  7401 .  FIG. 118(A)  is a front cross sectional view of the mobile telephone  7401 , and  FIG. 118(B)  is a side cross sectional view of the mobile telephone  7401  taken in the B 2 -B 2  cross section of  FIG. 118(A) . As shown in  FIG. 118(A) , the configuration of cartilage conduction units  7424 ,  7426  and a linking unit  7427  in the seventy-eighth embodiment, as well as the structure by which the cartilage conduction unit  7424  holds in cantilever fashion a piezoelectric bimorph element  2525  as a cartilage conduction vibration source for transmitting vibration to the cartilage conduction unit  7424 , are shared inter alia with the structure of the sixty-fifth embodiment shown in  FIG. 97(B) . Consequently, to avoid redundancy, descriptions of the significance of these structures are omitted. Like the sixty-first embodiment of  FIG. 91 , a feature of the seventy-eighth embodiment of  FIG. 118  is that the internal weight of the mobile telephone  7410  is utilized in order to suppress a modicum of sound leakage due to transfer of vibration of the cartilage conduction vibration source  2525  to the chassis of the mobile telephone  7401 . The details of the other internal configuration of the mobile telephone  7401  are shared with the embodiments described up to this point (for example, the fifty-fourth embodiment of  FIG. 82 , the seventy-second embodiment of  FIG. 107 , and the like), and therefore in  FIG. 118 , illustrations of these have been omitted to avoid complexity. 
     A sound leakage suppression structure employed in the seventy-eighth embodiment of  FIG. 118  is described below. In the same fashion as in the sixty-fifth embodiment of  FIG. 97 , cartilage conduction units  7424 ,  7426  and a linking unit  7427  are integrally molded from a hard material. This hard material is a material of different acoustic impedance than the chassis of the mobile telephone  7401 . An elastic body  7465  is interposed, as a vibration isolating material, between the chassis of the mobile telephone  7401  and the integrally molded structure of the cartilage conduction units  7424 ,  7426  and the linking unit  7427 , and connects the two such that there is not direct contact between them. This structure provides acoustic blocking between the chassis of the mobile telephone  7401 , and the integrally molded structure of the cartilage conduction units  7424 ,  7426  and the linking unit  7427 . The preceding structure is shared with embodiments described previously, but as it constitutes the base of the sound leakage suppression structure in the seventy-eighth embodiment, the significance thereof has been summed up once again. 
     A cell  7448  is held at top and bottom by hard cell holders (an upper holder  7406  and a lower holder  7416 ). In a center part of the cell  7448 , containment by the rigid holders is avoided, so as to permit swelling associated with the passage of time during use. The upper holder  7406  is furnished with a plurality of pins  7408  for connection to the front surface and rear surface of the mobile telephone  7401 , in sections of small cross-sectional area. Meanwhile, the lower holder  7416 , which is situated at a location away from the plurality of pins  7408 , is furnished with a plurality of elastic bodies  7467  which hold it in a vibration-isolated state, to the front surface and rear surface of the mobile telephone  7401 . 
     In so doing, as shown in  FIG. 118(B) , the cell  7448  installed in the cell holders (the upper holder  7406  and the lower holder  7416 ) is placed within a front side chassis  7401   a  (GUI display part  7405  side), and when covered up with a rear side chassis  7401   b , the plurality of pins  7408  are respectively sandwiched between the front side chassis  7401   a  and the rear side chassis  7401   b  and become pressed into contact thereagainst, whereby the load of the cell  7448  is connected, via the upper holder  7406 , to the chassis of mobile telephone  7401 , in proximity to the cartilage conduction unit  7424 . The significance of the small-cross-sectional area connections afforded by the pins  7408  is that the load connection locations are specifically concentrated in proximity to the cartilage conduction unit  7424  in the chassis of the mobile telephone  7401 . This load connection serves to suppress vibration of the chassis of the mobile telephone  7401  in proximity to the cartilage conduction unit  7424 , which corresponds to the entrance section for vibration transmission. The effect of this is comparable, for example, to that of a damper attached to the bridge of a stringed instrument corresponding to the entrance section for vibration of the strings, and serves to suppress resonance of the entire chassis of the mobile telephone  7401 . 
     Because the cartilage conduction unit  7424  is constituted by a material of different acoustic impedance than the chassis of the mobile telephone  7401 , and is vibration-isolated with respect to the chassis of the mobile telephone  7401  by the elastic body  7465 , a high degree of freedom of vibration is ensured, the effect of vibration suppression due to load connection of the cell  7448  are minimal, and satisfactory cartilage conduction can be obtained. 
     Meanwhile, the plurality of elastic bodies  7467  furnished to the lower holder  7416  are likewise sandwiched between the front side chassis  7401   a  and the rear side chassis  7401   b  and become pressed into contact thereagainst, in which state, due to the elasticity thereof, the lower holder  7416  has a high degree of freedom with respect to the chassis of the mobile telephone  7401 , and the load connection is weak. Consequently, despite fact that the lower holder  7416  is held by the plurality of elastic bodies  7467  in a section situated away from the plurality of pins  7408 , specific concentration of the load connection locations provided by the plurality of pins  7408  is not diminished. 
     Seventy-Ninth Embodiment 
       FIG. 119  is a cross sectional view relating to a seventy-ninth embodiment according to an aspect of the present invention, configured as a mobile telephone  7501 . The seventy-ninth embodiment has much in common with the seventy-eighth embodiment in  FIG. 118 , and therefore the same reference numerals are assigned to common portions, and descriptions thereof are omitted. 
     A point of difference between the seventy-ninth embodiment and the seventy-eighth embodiment lies is that the lower holder  7416  is also furnished with a plurality of pins  7408 , in place of the plurality of elastic bodies  7467 . In so doing, when sandwiched by the front side chassis  7401   a  and the rear side chassis  7401   b , the lower holder  7416  is also provided with a small cross-sectional area connection by the pins  7408 . In the case of the seventy-ninth embodiment, the load connection locations of the cell are dispersed, but as the vibration suppressing effect is dependent upon the distance between the load connection locations and the cartilage conduction unit  7424 , the load connection afforded by the plurality of pins  7408  of the upper holder  7406  remains effective. Consequently, in cases in which priority is given to using common parts for the structures of both the upper holder  7406  and the lower holder  7416  in order to reduce the number of parts, even at the expense of some vibration suppressing effect, it is possible to adopt the configuration of the seventy-ninth embodiment. 
     Eightieth Embodiment 
       FIG. 120  is a cross sectional view relating to an eightieth embodiment according to an aspect of the present invention, configured as a mobile telephone  7601 . The eightieth embodiment has much in common with the seventy-eighth embodiment in  FIG. 118 , and therefore the same reference numerals are assigned to common portions, and descriptions thereof are omitted. 
     A point of difference between the eightieth embodiment and the seventy-eighth embodiment lies is that the elastic body  7465  between the chassis of the mobile telephone  7401  and the integrally molded structure of the cartilage conduction units  7424 ,  7426  and the linking unit  7427  has been omitted. In cases in which sufficient vibration isolating effect can be obtained simply from the difference in acoustic impedance between the aforedescribed integrally molded structure and the chassis, the vibration suppression of the chassis by load connection of the cell  7448  does not appreciably extend to the integrally molded structure, and satisfactory cartilage conduction can be ensured. Consequently, in cases in which priority is given to reducing the number of parts, even at the expense of some cartilage conduction efficiency, to simplify the connection structure of the integrally molded structure and the chassis, it is possible to adopt the configuration of the eightieth embodiment. 
     Eighty-First Embodiment 
       FIG. 121(A)  is a side sectional view relating to an eighty-first embodiment according to an aspect of the present invention, configured as a mobile telephone  7701   a . The eighty-first embodiment has much in common with the seventy-eighth embodiment in  FIG. 118 , and therefore the same reference numerals are assigned to common portions, and descriptions thereof are omitted. Illustration of a front cross sectional view has been omitted as well. 
     A point of difference between the eighty-first embodiment and the seventy-eighth embodiment is that the weight utilized for suppressing noise leakage is provided by an internal frame structure  7784   a  of the mobile telephone  7701   a . The internal frame structure  7784   a  holds the cell  7448 , as well as holding internal structures such as circuits and the like, and constitutes the majority of the weight of the mobile telephone  7701   a . The internal frame structure  7784   a  is connected via an elastic body  7465  to the integrally molded structure of the cartilage conduction units  7424 ,  7426  and the linking unit  7427 , and forms the main skeletal structure of the mobile telephone  7701   a . Therefore, the chassis of the mobile telephone  7701   a  is an exterior component covering the perimeter of the mobile telephone  7701   a.    
       FIG. 121(A)  is a side sectional view relating to the eighty-first embodiment according to an aspect of the present invention, configured as the mobile telephone  7701   a . The eighty-first embodiment has much in common with the seventy-eighth embodiment in  FIG. 118 , and therefore the same reference numerals are assigned to common portions, and descriptions thereof are omitted. Illustration of a front cross sectional view has been omitted as well. 
     In the same manner as in the seventy-eighth embodiment in  FIG. 118 , vibration of the chassis constituting the front surface of the mobile telephone  7701   a  is suppressed in proximity to the cartilage conduction unit  7424 , by the weight of the internal frame structure  7784   a.    
       FIG. 121(B)  is a side sectional view relating to the eighty-first embodiment according to an aspect of the present invention, configured as a mobile telephone  7701   b . The first modification example of  FIG. 121(B)  has much in common with the eighty-first embodiment in  FIG. 121(A) , and therefore the same reference numerals are assigned to common portions, and descriptions thereof are omitted. 
     In the first modification example of  FIG. 121(B) , as in the eighty-first embodiment of  FIG. 121(A) , an internal frame structure  7748   b  is connected, via the elastic body  7465 , to the integrally molded structure of the cartilage conduction units  7424 ,  7426  and the linking unit  7427 . However, the chassis of the mobile telephone  7701   b  in the first modification example simply functions as an exterior component covering the perimeter of the mobile telephone  7701   b , and is not directly connected to the integrally molded structure of the cartilage conduction units  7424 ,  7426  and the linking unit  7427 , but is instead held by the internal frame structure  7748   b  via an elastic body  7765  which constitutes the vibration isolating material. For this reason, portions of the internal frame structure  7784   b  in proximity to the cartilage conduction unit  7424  intervene between the integrally molded structure and the chassis, in the form of exterior facing integrated with the internal frame structure  7748   b . In this manner, in the first modification example of  FIG. 121(B) , the internal frame structure  7748   b  which constitutes the majority of the weight of the mobile telephone  7701   b  is connected to the integrally molded structure of the cartilage conduction units  7424 ,  7426  and the linking unit  7427 , serving to suppress vibration of the chassis constituting the outer face of the mobile telephone  7701   b , due to the chassis being held by the internal frame structure  7748   b  via the vibration isolating material  7765 . 
       FIG. 121(C)  is a side sectional view relating to a second modification example of the eighty-first embodiment according to an aspect of the present invention, configured as a mobile telephone  7701   c . The second modification example of  FIG. 121(C)  has much in common with the first modification example of  FIG. 121(B) , and therefore the same reference numerals are assigned to common portions, and descriptions thereof are omitted. 
     A point of difference between the second modification example of  FIG. 121(C)  and the first modification example of  FIG. 121(B)  is that the elastic body interposed between an internal frame structure  7748   c  and the integrally molded structure of the cartilage conduction units  7424 ,  7426  and the linking unit  7427  has been omitted. In cases in which vibration suppression due to an acoustic impedance differential of the integrally molded structure and the internal frame structure  7748   c  does not appreciably extend to the integrally molded structure, and satisfactory cartilage conduction can be ensured, it is possible to adopt such a simplified, direct-connection configuration. That is, in cases in which priority is given to reducing the number of parts, even at the expense of some cartilage conduction efficiency, to simplify the connection structure of the integrally molded structure and the internal frame structure  7748   c , it is possible to adopt the configuration of the second modification example. 
     In the above manner, in the first modification example of  FIG. 121(B)  or the second modification example of  FIG. 121(C) , in the first instance, the internal frame structure  7748   b  or  7748   c , which constitutes a majority of the weight, is connected to the integrally molded structure of the cartilage conduction units  7424 ,  7426  and the linking unit  7427 , suppressing vibration. The chassis, which represents a small proportion of the weight, is then connected to the internal frame structure  7748   b  or  7748   c  via the vibration isolating material, suppressing vibration of the chassis constituting the outside surface of the mobile telephone  7701   b  or  7701   c.    
     Various modifications of the aforedescribed embodiments are possible provided that the advantages thereof can be enjoyed while doing so. For example, in the seventy-eighth embodiment of  FIG. 118 , in cases in which the elastic body  7465  has high vibration isolating effect, the integrally molded structure of the cartilage conduction units  7424 ,  7426  and the linking unit  7427 , and the chassis of the mobile telephone  7401 , may be configured of materials having the same acoustic impedance (for example, a common material for both). In cases in which the elastic body  7465  has high vibration isolating effect, there can be achieved a state comparable to one of different acoustic impedance between the integrally molded structure of the cartilage conduction units  7424 ,  7426  and the linking unit  7427 , and the chassis of the mobile telephone  7401 , due to interposition of the elastic body  7465 , whereby satisfactory cartilage conduction can be obtained, in spite of vibration suppression of the chassis due to the weight of the cell  7448  being connected thereto. 
     The features of the present invention described above are not limited to implementation in the aspects in the aforedescribed embodiments, and may be implemented in other aspects as well, provided that the advantages thereof can be enjoyed by doing so. For example, the structures of the eightieth embodiment shown in  FIG. 120  and the second modification example of the eighty-first embodiment shown in  FIG. 121(C)  are not limited to cases in which the cartilage conduction units are made of hard material, and are also suitable in cases in which the cartilage conduction units are elastic bodies, as in, for example, the forty-sixth embodiment of  FIG. 69 , and the modification example thereof in  FIG. 71 . The reason is that a cartilage conduction unit made of an elastic body will have greatly different acoustic impedance from the chassis, and even when the weight of the internal structure of the mobile telephone is connected to the chassis in proximity to the cartilage conduction unit, cartilage conduction by the cartilage conduction unit will not be impaired. In a case of applying the eightieth embodiment of  FIG. 120  to a structure in which the cartilage conduction vibration source (piezoelectric bimorph element)  2525  is supported from both sides by left and right cartilage conduction units (the elastic body units  4263   a ,  4263   b ) as in the forty-sixth embodiment and the modification example thereof, the upper holder  7406  may be extended towards the left-ear cartilage conduction unit (elastic body unit  4263   a ) side, and the pins  7408  arranged not just in proximity to the elastic body unit  4263   b , but in proximity to the elastic body unit  4263   a  as well. 
     Eighty-Second Embodiment 
       FIG. 122  is a block diagram relating to an eighty-second embodiment according to an aspect of the present invention, and is constituted as a cartilage conduction vibration source device for a mobile telephone. The eighty-second embodiment has much in common with the seventy-sixth embodiment of  FIG. 116 , and therefore the same reference numerals are assigned to common portions, omitting descriptions thereof unless necessary. Like the seventy-sixth embodiment of  FIG. 116 , the eighty-second embodiment provides a cartilage conduction vibration source device controllable by the application processor  7039  and the power management circuit  7053  in an ordinary mobile telephone, and more specifically, one in which the cartilage conduction vibration source device is configured as a piezoelectric bimorph element  7013  and a driver circuit  7503  therefor. There are differences between the eighty-second embodiment of  FIG. 122  and the seventy-sixth embodiment of  FIG. 116 , in terms of the configuration of a digital acoustic processing circuit  7538 , and of gain control in an analog output amp  7540 . 
     Firstly, the configuration of the digital acoustic processing circuit  7538  is described. Cartilage conduction can be defined as cartilage conduction in a broad sense or as cartilage conduction in a narrow sense. Cartilage conduction in a broad sense may be defined as sound output from a cartilage conduction unit, including cartilage-air conduction (the rate at which vibration transmitted from a cartilage conduction unit to cartilage of the ear changes to air conduction within the external auditory meatus, and is propagated to the inner ear through the eardrum), cartilage-bone conduction (the rate at which vibration transmitted from a cartilage conduction unit to cartilage of the ear is propagated directly to the inner ear through bone), and direct air conduction (the rate at which air-conducted sound generated from a cartilage conduction unit reaches the eardrum directly without going through cartilage, and is propagated to the inner ear). In contrast to this, cartilage conduction in the narrow sense is defined as sound propagated to the inner ear through cartilage, and includes the aforedescribed cartilage-air conduction and cartilage-bone conduction. 
     In a normal individual, the proportions of cartilage-air conduction and cartilage-bone conduction in cartilage conduction in the narrow sense are such that the latter is about 1/10 or less of the former, and thus cartilage-air conduction is extremely important. This is due to extremely poor impedance matching from cartilage to bone. In contrast to this, in a person with conductive hearing loss due to an abnormality of the external auditory meatus or middle ear, the proportion of cartilage-bone conduction is greater, as compared with a normal individual. This due to impaired cartilage-air conduction (and of course direct air conduction as well). 
     Next, with regard to the rate of participation by cartilage-air conduction in the broad sense, as described above, in a normal individual, participation by cartilage-bone conduction is small, and therefore one may focus substantially upon the proportions of cartilage-air conduction and direct air conduction. As a rule of thumb, cartilage-air conduction predominates in low-pitched regions, while direct air conduction predominates in high-pitched regions; at 500 Hz, substantially all conduction is cartilage-air conduction, while at 4000 Hz, substantially all conduction is direct air conduction. The frequency components necessary to discriminate some consonants such as the “sh” sound lie in a high frequency band close to 4000 Hz in which direct air conduction predominates. In mobile telephones, due to the fact that there are no problems whatsoever in terms of language discrimination during conversation, and to concerns relating to the amount of information, frequency components of about 3000 Hz and above are cut, so the importance of cartilage-air conduction is great. 
     With regard to cartilage-bone conduction, as described above, in a normal individual, the participation of cartilage-bone conduction in the broad sense is small, and it is thought that the frequency characteristics thereof are substantially close to flat from a low-frequency range to a high-frequency range. Incidentally, when there is a transition from an occluded condition to an unoccluded condition in the external auditory meatus, in low-frequency bands (500 Hz or the like), sound pressure within the external auditory meatus drops, but loudness (the perceived magnitude of sound) does not drop as much as the sound pressure. When there is a transition from an unoccluded condition to an occluded condition in the external auditory meatus, in high-frequency bands, sound pressure within the external auditory meatus drops, but loudness does not drop as much as the sound pressure within the external auditory meatus. This fact suggests that cartilage-bone conduction exists in both low-frequency bands and high-frequency bands, albeit to a very small extent. 
     In the digital acoustic processing circuit  7538  of  FIG. 122 , taking into account the frequency characteristics of cartilage-air conduction, cartilage-bone conduction, and direct air conduction in cartilage conduction in the broad sense described above, in combination with the degrees of participation thereof, a digital sound signal output from the application processor  7039  is input respectively to a cartilage-bone conduction equalizer  7538   a , a cartilage-air conduction equalizer  7538   b , and a direct air conduction equalizer  7538   c , which respectively perform optimal equalization in cases of cartilage-bone conduction only, cartilage-air conduction only, and direct air conduction only. Equalization here does not refer to equalization for the purpose of obtaining sounds closely approximating natural sounds, but rather to acoustic processing taking into account the frequency characteristics of the piezoelectric bimorph element  7013  serving as the cartilage conduction vibration source, in combination with the frequency characteristics in the respective transmission rates of cartilage-bone conduction, cartilage-air conduction, and direct air conduction, to propagate sound in the most efficient manner in terms of language discrimination ability. Consequently, equalization would include cases in which precedence is given to language discrimination ability, modifying the voice quality somewhat from its natural state, but not to the extent that the ability to identify the person is impaired. 
     In accordance with an instruction from the application processor  7039 , a synthesis unit  7538   d  of the digital acoustic processing circuit  7538  determines a mixing ratio of the outputs from the cartilage-bone conduction equalizer  7538   a , the cartilage-air conduction equalizer  7538   b , and the direct air conduction equalizer  7538   c , and modifies this ratio according to changes in conditions. The mixing ratio, which is directed in the first instance to a normal individual, is determined based on the frequency characteristics of a conversation taking place in a case in which the cartilage conduction unit is contacting the ear cartilage and the external auditory meatus is not occluded, but is modified when there is a change from this state. In specific terms, since sound not produced in the course of a call, such as playback of a voice memo, will not be cut off at 3000 Hz and above, the extent of participation of the direct air conduction equalizer  7538   c  is boosted. In a case in which the device has been set for use by a person with conductive hearing loss, the element relying on bone conduction is greater, and therefore the extent of participation of the cartilage-bone conduction equalizer  7538   a  is boosted. Further, when the occurrence of an earplug bone conduction effect has been detected, this means that external auditory meatus is occluded and that there is no direct air conduction, and therefore the participation of the direct air conduction equalizer  7538   c  is halted. The details of these processes are discussed below. 
     Next, automatic gain adjustment by the analog output amp  7540  will be described. A maximum input rating at which the piezoelectric bimorph element  7013  is capable of vibrating has been specified, and in the event that a signal exceeding this is output from the analog output amp  7540 , the sound becomes distorted, and bone conduction at the desired frequency characteristics cannot be achieved. On the other hand, in a case in which the maximum output from the analog output amp  7540  falls below the maximum input rating of the piezoelectric bimorph element  7013 , cartilage conduction that fully exploits the capabilities of the piezoelectric bimorph element  7013  cannot be achieved. A gain control unit  7540   a  sequentially monitors the average output of the DA converter  7138   c  for a predetermined duration, and controls a gain adjustment unit  7540   b  of the analog output amp  7540 , doing so in such a way that the output level of the analog output amp  7540  equals the maximum input rating level of the analog output amp  7540 . In so doing, the capabilities of the piezoelectric bimorph element  7013  can be utilized to the maximum, and bone conduction at the desired frequency characteristics can be achieved. 
       FIG. 123  is a flowchart showing the functions of the application processor  7039  in the eighty-second embodiment of  FIG. 122 . The flow in  FIG. 123  describes the functions of the driver circuit  7503 , and therefore operations centered on related functions have been extracted for illustration; however, there are other operations of the application processor  7039 , such as typical functions of mobile telephones and like, which are not represented in the flow of  FIG. 123 . The flow of  FIG. 123  starts when the main power source of the mobile telephone is turned on. In Step S 412 , initial startup and a function check of each unit are performed, as well as initiating screen display on a display unit of the mobile telephone. Next, in Step S 414 , the cartilage conduction unit and mobile telephone outgoing-talk unit functions are turned off, and the routine advances to Step S 416 . Turning off of the cartilage conduction units is accomplished by turning off the power supply to the driver circuit  7503  from the power management circuit  7053  of  FIG. 122 . 
     In Step S 416 , a check is performed to determine if an operation to playback a previously recorded voice memo has been performed. In the event that no voice memo playback operation has been detected, the routine proceeds to Step S 418 , and a check is performed to determine if the current state is one in which another caller&#39;s answer to a telephone call request, or a call through mobile radio waves based on an incoming call, is in progress. When the current state is the talk state, the routine proceeds to Step S 420 , the cartilage conduction units and the outgoing-talk unit are turned on, and routine proceeds to Step S 422 . 
     In Step S 422 , a check is performed to determine if a setting for a person with conductive hearing loss has been made, and in the event that this setting has not been made, the routine advances to Step S 424 . In Step S 424 , a check is performed to determine if the current state is one in which an earplug bone conduction effect has arisen due to closing of the external auditory meatus, and in the event this is not the case, the routine proceeds to Step S 426 , and advances to Step S 428 , without applying a signal in which the waveform of the user&#39;s own voice is inverted. The process of application/non-application of a waveform-inverted signal of the user&#39;s own voice has been described in Step S 52  to Step S 56  in the flow of  FIG. 10 , and therefore the details are omitted here. In Step S 428 , proportions of participation by the respective outputs of the equalizers  7538   a ,  7538   b , and  7538   c  are set to optimal values for the talk state appropriate to a normal individual, and the routine advances to Step S 430 . 
     On the other hand, when a state in which the earplug bone conduction effect has occurred due to closing of the external auditory meatus is detected in Step S 424 , the routine advances to Step S 431 , and a waveform-inverted signal of the user&#39;s own voice is added; also, in Step S 432 , participation by the direct air conduction equalizer  7538   c  is halted, whereupon the routine advances to Step S 430 . As noted previously, the reason for doing so is that there is no direct air conduction, due to closure of the external auditory meatus. In a case in which it has been detected in Step S 422  that a setting for a person with conductive hearing loss has been made, the routine advances to Step S 434 , the extent of participation by the cartilage-bone conduction equalizer  7538   a  is boosted, and routine advances to Step S 430 . 
     In Step S 430 , a check is performed to determine whether the call has ended, and in the event this is not the case, returns to Step S 422 , and repeats Step S 422  to Step S 434  for as long as the call has not ended. In so doing, participation by the respective outputs of the equalizers  7538   a ,  7538   b , and  7538   c  can be modified in response to changes in settings or conditions during a call. On the other hand, in the event that the call is detected to have ended in Step S 430 , the routine advances to Step S 436 , the cartilage conduction unit and the outgoing-talk unit functions are turned off, and routine proceeds to Step S 438 . 
     In contrast to this, in the event that a voice memo playback operation has been detected in Step S 416 , the routine advances to Step S 440 , and the extent of participation by the direct air conduction equalizer  7538   c  is boosted. The reason is that, in the aforedescribed manner, since sound not produced in the course of a call, such as that of playback of a voice memo, is not cut off at 3000 Hz and above, in terms of sound quality, it is appropriate to boost participation by direct air conduction. Next, in Step S 442 , the cartilage conduction units are turned on, the routine advances to Step S 444 , and a voice memo playback process is performed. Then, once the voice memo playback process is finished, the routine advances to Step S 446 , the cartilage conduction unit is turned off, and routine advances to Step S 438 . When the talk state is not detected in Step S 418 , the routine advances directly to Step S 438 . 
     In Step S 438 , a check performed to determine whether the main power source of the mobile telephone has been turned off, and in the event that the main power source is not off, Step S 416  to Step S 446  are subsequently repeated according to circumstances, for as long as turning off of the main power source is not detected in Step S 438 . In contrast to this, in the event that turning off of the main power source is detected in Step S 438 , the flow terminates. 
     Eighty-Third Embodiment 
       FIG. 124  is a perspective view relating to an eighty-third embodiment of an aspect of the present invention, and is configured as a notebook-type large-screen mobile telephone  7601  equipped with mobile telephone functionality.  FIG. 124(A)  is a front view of the mobile telephone  7601 . The mobile telephone  7601  is provided with a large-screen display unit  7605  that doubles as a touch panel. The mobile telephone  7601  is further provided with a cartilage conduction outgoing-talk/incoming-talk unit  7681  connected to the right edge thereof by a universal joint  7603 . The cartilage conduction outgoing-talk/incoming-talk unit  7681 , at its upper end, constitutes a cartilage conduction unit  7624 , and is furnished in its medial section with a microphone  7623 . As discussed below, the cartilage conduction outgoing-talk/incoming-talk unit  7681  has as structure whereby it is possible for the cartilage conduction unit  7624  to be withdrawn upward; in  FIG. 124(A) , however, the cartilage conduction outgoing-talk/incoming-talk unit  7681  is shown in the stowed state in which it is basically not being used. 
       FIG. 124(B)  shows a state in a case in which the mobile telephone functionality of the mobile telephone  7601  is being utilized; it will be appreciated that it is possible for the cartilage conduction unit  7624  to be withdrawn upward as shown by an arrow  7681   a , as well as for the cartilage conduction unit  7624  to be lowered forward as shown by an arrow  7681   b . Because the cartilage conduction outgoing-talk/incoming-talk unit  7681  is connected to the mobile telephone  7601  by the universal joint  7603  in the aforedescribed manner, the direction of lowering is not limited to the forward direction, and lowering can take place in any direction. 
     Due to the aforedescribed configuration, with the mobile telephone  7601 , for example, placed on a desktop and maintained in an orientation such that content displayed on the large-screen display unit  7605  (such as newspapers, e-books, graphics, or the like) can be viewed, the withdrawn cartilage conduction unit  7624  can be placed by hand against the cartilage of the ear, so that calls can be made by the mobile telephone. At this time, one&#39;s own voice can be picked up by the microphone  7623 , which is positioned close to the mouth during the call state. However, there is no limitation to this orientation, and it would be possible, while holding the mobile telephone  7601  in the hand, to appropriately adjust the withdrawn length and direction of the cartilage conduction outgoing-talk/incoming-talk unit  7681 , to place the cartilage conduction unit  7624  against the cartilage of the ear. The cartilage conduction unit  7624  is designed such that, even with the mobile telephone  7601  placed on the knees, by virtue of a structure resembling that of an antenna, the withdrawn length thereof is likewise sufficient to deal with such a case. 
     When the mobile telephone  7601  is used in the state shown in  FIG. 124(A) , when there is an incoming call to the mobile telephone, the call can be answered instantaneously by withdrawing the cartilage conduction outgoing-talk/incoming-talk unit  7681 . Further, when the operation of withdrawing the cartilage conduction outgoing-talk/incoming-talk unit  7681  is interlinked to the operation of answering the incoming call, one-touch operation is possible, further improving the ease of use. Likewise, when one wishes to place a mobile telephone call while using the mobile telephone  7601  in the state shown in  FIG. 124(A) , after performing an operation from the touch panel/large-screen display unit  7605  to choose a contact to be called, the cartilage conduction outgoing-talk/incoming-talk unit  7681  is withdrawn and placed against the ear. At this time, when the operation of withdrawing the cartilage conduction outgoing-talk/incoming-talk unit  7681  is interlinked to the call request operation, the call can be placed through a one-touch operation. 
     In  FIG. 124(B) , the mobile telephone is shown being used in an orientation in which the screen is viewed in landscape mode, but it would be possible to use the unit in portrait mode as well. For example, when used in portrait mode with the cartilage conduction outgoing-talk/incoming-talk unit  7681  side upward, the cartilage conduction outgoing-talk/incoming-talk unit  7681  may be used by extending it to reach the cartilage of the ear from the upper right corner of the portrait-oriented screen. Both in the case of a landscape-oriented screen and portrait-oriented screen, the cartilage conduction unit  7624  may be used while placed against the cartilage of the right ear, but the mobile telephone  7601  can be rotated to an orientation affording ease of listening with the left ear. For example, when the unit is used in landscape mode with the cartilage conduction outgoing-talk/incoming-talk unit  7681  side downward, the cartilage conduction outgoing-talk/incoming-talk unit  7681  can be used by extending it to reach the cartilage of the left ear from the lower left corner of the portrait-oriented screen. Further, when used in landscape mode flipped top to bottom from the state shown in  FIG. 124(B) , the cartilage conduction outgoing-talk/incoming-talk unit  7681  can be used by extending it to reach the cartilage of the left ear from the upper left corner of the landscape-oriented screen. In either case, because the cartilage conduction unit  7624  is linked to the mobile telephone  7601  by the universal joint  7603  and the cartilage conduction outgoing-talk/incoming-talk unit  7681 , which is extendable and retractable from the mobile telephone  7601  without being separated therefrom, the configuration is easy to use, even during use while being carried around. 
       FIG. 125  is a perspective view showing a modification example of the eighty-third embodiment of  FIG. 124 , and like the eighty-third embodiment, is configured as a notebook-type large-screen mobile telephone  7701  equipped with mobile telephone functionality. A point of difference between the modification example of  FIG. 125  and the eighty-third embodiment of  FIG. 124  is that the device is provided with a cartilage conduction outgoing-talk/incoming-talk unit  7781  connected by a universal joint  7703  at the upper right corner of the right edge of a touch panel/large-screen display unit  7705  when used in portrait mode. As a result, the cartilage conduction unit  7624  is situated at the bottom end of the cartilage conduction outgoing-talk/incoming-talk unit  7781 . In this modification example, a microphone  7723  is furnished on the main body side of the mobile telephone  7701 . 
     Due to the aforedescribed structure, it is possible for the cartilage conduction unit  7724  to be drawn downward as shown by an arrow  7781   a , as well as raised forward as shown by an arrow  7781   b . As the cartilage conduction outgoing-talk/incoming-talk unit  7781  is connected to the mobile telephone  7701  by the universal joint  7701  in the same manner as in the eighty-third embodiment of  FIG. 124 , the direction of raising is not limited to a forward direction, and raising can take place in any direction. In the case of the modification example of  FIG. 125 , when used as illustrated in the portrait mode, the cartilage conduction outgoing-talk/incoming-talk unit  7781  is used by extending it to reach the cartilage of the right ear from the upper right corner of the portrait-oriented screen. In contrast to this, when, for example, used in landscape screen mode with the cartilage conduction outgoing-talk/incoming-talk unit  7781  side down, the cartilage conduction outgoing-talk/incoming-talk unit  7781  is used by extending it to reach the cartilage of the right ear from the lower right corner of the landscape-oriented screen. The modification example of  FIG. 125 , like the eighty-third embodiment of  FIG. 124 , can be used easily while placed against the left ear in either portrait screen mode or landscape screen mode, through appropriate rotation of the screen. 
     In both the eighty-third embodiment of  FIG. 124  and the modification example thereof in  FIG. 125 , the cartilage conduction unit may be configured from a piezoelectric bimorph element, or configured from an electromagnetic vibrator. The structure of the eighty-third embodiment of  FIG. 124  and the modification example thereof in  FIG. 125  is not limited to a cartilage conduction system, and a configuration in which an earphone comprising an ordinary air-conduction speaker is attached at the location of the cartilage conduction unit would also be acceptable. 
     Implementation of the present invention is not limited to the aforedescribed embodiments, and the various advantages of the present invention can be enjoyed in other embodiments as well. Further, these features may be interchanged or utilized in combination among various embodiments. For example, in the eighty-second embodiment shown in  FIG. 122  and  FIG. 123 , the cartilage-bone conduction equalizer  7538   a , the cartilage-air conduction equalizer  7538   b , and the direct air conduction equalizer  7538   c  are respectively shown as hardware blocks, but identical functions could be accomplished through digital acoustic processing circuit software as well. Further, in the configuration in the eighty-second embodiment, modification of the equalizers according to conditions entails modifying the mixing ratios of the outputs of three equalizers; however, provided that the final output of the digital acoustic processing circuit  7538  is comparable, modification of the equalizers may be performed in block. 
     Eighty-Fourth Embodiment 
       FIG. 126  is a perspective view and a cross sectional view relating to an eighty-fourth embodiment according to an aspect of the present invention, configured as an ordinary mobile telephone  7801  and cartilage conduction soft cover  7863  therefor.  FIG. 126(A)  is a perspective view of the ordinary mobile telephone  7801  of the eighty-fourth embodiment and the sheathing cartilage conduction soft cover  7863 , seen from the front face. Due to the elasticity of the cartilage conduction soft cover  7863 , the ordinary mobile telephone  7801  is protected in the event that the ordinary mobile telephone  7801  is dropped by accident or the like, and the upper right side corner of the cover also serves as a cartilage conduction unit  7824 , as will be discussed below. The ordinary mobile telephone  7801  is a mobile telephone of ordinary smartphone type, having a microphone  23  and an earphone  213  comprising an air-conduction speaker. The left upper part of the mobile telephone  7801  is furnished with an external earphone jack for an external earphone. Meanwhile, the cartilage conduction soft cover  7863  is furnished with an external earphone plug  7885 ; sound signals for vibrating the cartilage conduction unit  7824  are conducted from the external earphone plug  7885  which is plugged into the external earphone jack. 
     To sheath the ordinary mobile telephone  7801  in the cartilage conduction soft cover  7863 , firstly, the cartilage conduction soft cover  7863  is turned nearly inside-out, and the external earphone plug  7885  is inserted into the external earphone jack; thereafter, the ordinary mobile telephone  7801  in its entirety is sheathed in the cartilage conduction soft cover  7863 . Once the external earphone plug  7885  has been inserted into the external earphone jack from the outside, sound output from the earphone  213  turns off, and sound signals for vibrating the cartilage conduction unit  7824  are output from the external earphone jack. Because a portion of the cartilage conduction soft cover  7863  constitutes the cartilage conduction unit  7824 , an elastic material having acoustic impedance close to that of ear cartilage (silicone rubber, mixtures of silicone rubber and butadiene rubber, natural rubber, or structure of these with air bubbles sealed therein) is adopted. 
       FIG. 126(B)  is a cross-sectional view of an upper part of the cartilage conduction soft cover  7863  taken in B 1 -B 1  cross section in  FIG. 126(A) , through a plane perpendicular to the front surface and the side faces of the cartilage conduction soft cover  7863 . From  FIG. 126(B)  it will be clear that the upper right side corner of the cartilage conduction soft cover  7863  constitutes the cartilage conduction unit  7824 , and an electromagnetic vibrator  7825  constituting a cartilage conduction vibration source is embedded to the inside thereof. The upper part of the cartilage conduction soft cover  7863  is furnished with a conduction part driver  7840  for driving the electromagnetic vibrator  7825 , and with a replaceable power source cell  7848  for supplying power thereto. The electromagnetic vibrator  7825  vibrates when driven by the conduction part driver  7840  on the basis of a sound signal input from the external earphone plug  7885 . The direction of vibration is a direction perpendicular to a large-screen display unit  7805  of the ordinary mobile telephone  7801  (see  FIG. 126(A) ) as shown by an arrow  7825   a.    
       FIG. 126(C)  is a cross-sectional view of an upper part of the cartilage conduction soft cover  7863  taken in B 21 -B 2  cross section in  FIG. 126(A)  or  FIG. 126(B) , through a plane perpendicular to the front surface and the top face of the ordinary mobile telephone  7801  and the cartilage conduction soft cover  7863 . As will be appreciated from  FIG. 126  (C), by sheathing the ordinary mobile telephone  7801  in the cartilage conduction soft cover  7863 , the electromagnetic vibrator  7825  serving as the cartilage conduction vibration source is integrated with the ordinary mobile telephone  7801 , and vibrates in response to the sound signal supplied by the external earphone plug  7885 . In so doing, simply by sheathing the ordinary mobile telephone  7801  in the cartilage conduction soft cover  7863  without making any additional modifications, the unit can be transformed into a cartilage conduction type mobile telephone similar, for example, to the sixtieth embodiment of  FIG. 90 . 
     In the eighty-fourth embodiment of  FIG. 126 , when the ordinary mobile telephone  7801  is sheathed in the cartilage conduction soft cover  7863  in the aforedescribed manner, the cartilage conduction unit  7824  is formed exclusively in the right side corner as seen in the drawing. This state is one suitable for making a call while holding the ordinary mobile telephone  7801  with the right hand and listening with the right ear. To hold the unit with the left hand and listen with the left ear, the ordinary mobile telephone  7801  would be switched between hands so as to face it rearward and thereby face the cartilage conduction unit  7824  towards the left ear, in the manner described in the twelfth embodiment of  FIG. 22  and the thirty-sixth embodiment of  FIG. 56 . 
       FIG. 127  is a block diagram of the eighty-fourth embodiment of  FIG. 126 . In the block diagram, the ordinary mobile telephone  7801  has much in common with the ordinary mobile telephone  1601  in the sixty-ninth embodiment of  FIG. 102 , and therefore the same reference numerals have been assigned to common parts, and descriptions are omitted. A point of difference between  FIG. 127  and  FIG. 102  is that the short-range communication unit  1446  has been omitted from the illustration in  FIG. 127 , while an external earphone jack  7846  is illustrated. However, this does not mean that the ordinary mobile telephone  1601  of  FIG. 102  and the ordinary mobile telephone  7801  of  FIG. 127  are in fact different, but merely that appropriate omission of illustration has been made, as required by the description. 
     As will be clear from the block diagram of  FIG. 127 , in a state in which the ordinary mobile telephone  7801  has been sheathed in the cartilage conduction soft cover  7863 , the external earphone plug  7885  is inserted into the external earphone jack  7846  of the ordinary mobile telephone  7801 , and the conduction unit driver  7840  drives the electromagnetic vibrator  7825  on the basis of sound signals output from an incoming-talk-processing unit  212  of the ordinary mobile telephone  7801 . 
       FIG. 128  is cross sectional views showing a modification example of the eighty-fourth embodiment of  FIG. 126 . Common reference numerals have been assigned to portions in common with  FIG. 126 , omitting descriptions thereof, and describing only the different portions.  FIG. 128(A)  is a cross sectional view of the cartilage conduction soft cover  7963  sheathing the ordinary mobile telephone  7801 , seen from the front face, with the upper part split lengthwise. As will be clear from  FIG. 128(A)  and  FIG. 128(B) , the cartilage conduction soft cover  7863  of the modification example is furnished with a cavity  7963   a , and an external earphone plug  7985  is arranged in such a way as to be able move freely within the cavity  7963   a . Consequently, prior to sheathing the ordinary mobile telephone  7801  in the cartilage conduction soft cover  7963 , the external earphone plug  7985  readily inserts into the external earphone jack  7846 . Then, once it is confirmed that the external earphone plug  7985  has been correctly inserted into the external earphone jack  7846  of the ordinary mobile telephone  7801 , the ordinary mobile telephone  7801  can be sheathed within the cartilage conduction soft cover  7863 . 
     A second point of difference between the modification example of  FIG. 128  and the eighty-fourth embodiment of  FIG. 126  is that the cartilage conduction soft cover  7963  is furnished with a relay external earphone jack  7946 . In so doing, despite the fact that the original external earphone jack  7846  of the ordinary mobile telephone  7801  is obstructed, in cases in which it is desired to listen to music or the like, it is possible to use the unit in the customary manner, through insertion of an ordinary external earphone or the like into the relay external earphone jack  7946 . The relay external earphone jack  7946  is furnished with a switch  7946   a  which, in a case in which a sound signal is being propagated from the external earphone plug  7985  to the conduction unit driver  7840 , and an ordinary external earphone or the like has been inserted into the relay external earphone jack  7946 , will ordinarily switch the sound signal from the external earphone plug  7985  so as to be output from the relay external earphone jack  7946 . 
       FIG. 129  is a block diagram of a modification example of the eighty-fourth embodiment of  FIG. 128 . Common reference numerals have been assigned to portions in common with ones in the eighty-fourth embodiment of  FIG. 127 , and descriptions thereof are omitted. Identical reference numerals have been assigned also to portions identical to  FIG. 128 , omitting descriptions unless necessary. As will be clear from  FIG. 129 , a sound signal from the external earphone plug  7985  is branched by the switch  7946   a ; ordinarily, the sound signal will be propagated from the external earphone plug  7985  to the conduction unit driver  7840  while mechanically detecting insertion of an ordinary external earphone or the like into the relay external earphone jack  7946 , to thereby switch the sound signal from the external earphone plug  7985  by a mechanical switch, so as to be output from the relay external earphone jack  7946 . 
     Eighty-Fifth Embodiment 
       FIG. 130  is a perspective view and a cross sectional view relating to an eighty-fifth embodiment according to an aspect of the present invention, and to a modification example thereof, configured as a mobile telephone  8001  or  8001   x . The eighty-fifth embodiment of  FIG. 130  has much in common with the fifty-fifth embodiment of  FIG. 83 , and therefore the same reference numerals have been assigned to common parts, and descriptions are omitted. The eighty-fifth embodiment of  FIG. 130  differs from the fifty-fifth embodiment of  FIG. 83  in that only the right cartilage conduction unit  5124  at the right side in the drawing is provided, and in terms of the associated configuration of a microphone  8023  or  8123 . 
     As will be clear from  FIG. 130(A)  and from  FIG. 130(B)  showing a B 1 -B 1  cross section thereof, in the eighty-fifth embodiment, the cartilage conduction unit  5124  is furnished at one side only. Consequently, in the same manner as the twelfth embodiment of  FIG. 22 , the thirty-sixth embodiment of  FIG. 56 , and the eighty-fourth embodiment of  FIG. 126 , in the illustrated state, the cartilage conduction unit  5124  is used while held against the right ear, but may be switched between hands so that the mobile telephone faces  8001  rearward, in order to use the cartilage conduction unit  5124  while held against the left ear. In association therewith, the user&#39;s mouth will be positioned to the front surface side, or to the rear surface side, of the mobile telephone  8001 . 
     As will be clear from  FIG. 130(A) , to accommodate use of the cartilage conduction unit  5124  from both the front and back sides in this manner, the microphone  8023  is furnished in lower part of the right side surface of the mobile telephone  8001 . The microphone  8023  is configured such that directionality  8023   a  to pick up sound from the front surface side and directionality  8023   b  to pick up sound from the rear surface side are symmetrical, and such that the voice is picked up evenly from the rear side. In so doing, the user&#39;s voice can be picked up evenly, both in cases in which a call is made with the cartilage conduction unit  5124  placed against the right ear so that the front surface side of the mobile telephone  8001  is opposed to the face, and in cases in which a call is made with the cartilage conduction unit  5124  placed against the left ear so that the rear surface side of the mobile telephone  8001  is opposed to the face. 
       FIG. 130(C)  is a modification example of the eighty-fifth embodiment, showing the mobile telephone  8001   x  viewed from the bottom surface side. This modification example of the eighty-fifth embodiment differs only in the placement of the microphone  8123 , and in other respects is identical to the eighty-fifth embodiment; therefore only the bottom surface is shown in  FIG. 130(C) , omitting the rest from the illustration. As will be clear from  FIG. 130(C) , in the modification example of the eighty-fifth embodiment, the microphone  8123  is furnished at the right side of the lower surface of the mobile telephone  8001   x . In the same manner as in the eighty-fifth embodiment, the microphone  8123  is constituted such that directionality  8123   a  to pick up sound from the front surface side and directionality  8123   b  to pick up sound from the rear surface side are symmetrical. In so doing, in the modification example as well, the user&#39;s voice can be picked up evenly, both in cases in which a call is made from the front surface side of the mobile telephone  8001   x , and cases in which a call is made from the rear surface side. It goes without saying that the cartilage conduction unit  5124  can be employed in common, in both instances. 
     The features of the present invention described above are not limited to implementation in the aforedescribed embodiments, and are implementable in other aspects provided that the advantages thereof can be enjoyed. For example, in the eighty-fourth embodiment of  FIG. 126 , the left side in the drawing is not furnished with a cartilage conduction unit, in order that the external earphone plug  7885  may be placed there; however, in cases in which no connection terminal for a sound signal from the external earphone pack  7846  or the like is present at the upper surface of the ordinary mobile telephone  7801 , it would be possible, utilizing the space on the upper surface, to have cartilage conduction units at both the left and right corners. While a separate power source cell  7848  was provided for operation of the conduction unit driver  7840 , in cases in which the external output level of the ordinary mobile telephone  7801  is sufficient for direct driving of the cartilage conduction unit  7824 , it would be possible to omit the power source. In cases in which power source supply is not necessary for operation of the conduction unit driver  7840 , or in cases in which an output terminal of the ordinary mobile telephone  7801  is configured such that power source supply together with the sound signal is possible, there is no need to have the separate power source cell  7848 . Further, in the eighty-fourth embodiment, the electromagnetic vibrator  7825  was adopted as the cartilage conduction vibration source, but there is no limitation to this, and a piezoelectric bimorph element may be adopted as the cartilage conduction vibration source, as in other embodiments, as long as it is possible for the conduction unit driver  7840  to operate on the basis of power supply from a separate power source or from the ordinary mobile telephone  7801 . 
     In the eighty-fourth embodiment of  FIG. 126 , the mobile telephone accessory device for vibrating the cartilage conduction unit on the basis of external audio output of the ordinary mobile telephone was configured as a soft cover; however, implementation of the present invention is not limited to this. For example, depending on the shape of the mobile telephone and the placement of the external audio output terminal, the device may be configured as a hard case type mobile telephone accessory device of a shape that clips onto the upper part of the mobile telephone. In this case, when an external earphone jack is situated in the upper part of the mobile telephone, it is possible to utilize an external earphone plug section inserted into the external earphone jack, to position the mobile telephone accessory device and to support it in the clipped state. 
     In the eighty-fifth embodiment of  FIG. 130 , depending on the directionality settings of the microphone  8023  or  8123 , there is a significant possibility of picking up outside noise; however, in cases in which the environment-noise microphone of the first example of  FIG. 1  or the fiftieth embodiment of  FIG. 75  is provided, this could be utilized to cancel the outside noise. 
     Eighty-Sixth Embodiment 
       FIG. 131  is a block diagram relating to an eighty-sixth embodiment according to an aspect of the present invention, configured as a mobile telephone  8101 . The block diagram of  FIG. 131  relating to the eighty-sixth embodiment has much in common with the block diagram of  FIG. 82  relating to the fifty-fourth embodiment, and therefore identical reference numerals have been assigned to identical portions, and descriptions are omitted. The eighty-sixth embodiment of  FIG. 131  differs from the fifty-fourth embodiment of  FIG. 82  in terms of the configuration of a cartilage conduction equalizer  8138 , the details of which are discussed below. Additionally,  FIG. 131  depicts an external earphone jack  8146  for connecting an earphone to listen to sound from an incoming-call processing unit  212 , and a short-range wireless communication unit  8147  for short-range wireless communication with a mobile telephone accessory device, such as a headset designed to be worn on the head. 
     Next, employing  FIG. 132 , the functions of the cartilage conduction equalizer  8138  in the eighty-sixth embodiment of  FIG. 131  will be described.  FIG. 132(A)  is an image diagram of the frequency characteristics of a piezoelectric bimorph element constituting a cartilage conduction vibration source in a cartilage conduction vibration unit  228  employed in the eighty-sixth embodiment, showing the results of measurements of vibrational acceleration level at each frequency. As will be clear in  FIG. 132(A) , the piezoelectric bimorph element vibrates strongly in a frequency band of 800 Hz and above, but exhibits generally flat frequency characteristics up to about 10 kHz, aside from a few peaks and valleys. 
       FIG. 132(B)  is an image diagram of results of measurements of vibrational acceleration level of ear cartilage at each frequency, while a piezoelectric bimorph element like that described above has been placed into contact with ear cartilage. As will be clear from  FIG. 132(B) , ear cartilage exhibits large vibrational acceleration levels approaching those of the 1-2 kHz band, even in a band of 1 kHz or below, in which vibration of the piezoelectric bimorph element serving as the vibration source is relatively weak. This means that, in the frequency characteristics of ear cartilage, there is satisfactory transmission of vibration in a band of 1 kHz or below. Further, as will be clear from  FIG. 132(B) , despite the fact that vibration of the piezoelectric bimorph element serving as the vibration source is generally flat, ear cartilage exhibits a drop in vibrational acceleration level in a high frequency band starting from around 3 kHz. This means that, in the frequency characteristics of ear cartilage, vibration transmission efficiency drops in a high frequency band starting from around 3 kHz. 
     From examination of a graph showing an example of empirical data for the mobile telephone of the forty-sixth embodiment shown in  FIG. 79  on the basis of the above results, it is understood that the amplification of sound pressure, for example, in a 300 Hz-2500 Hz band, due to a transition from non-contact state shown by a solid line to a contact state shown by a single-dotted broken line, represents an aggregation of air-conducted sound in the non-contact state, plus air-conducted sound arriving via cartilage conduction through ear cartilage having the frequency characteristics shown in  FIG. 132(B) . The fact that the difference between the non-contact state shown by the solid line and the contact state shown by the single-dotted line is smaller in a band to the high-frequency end of 2500 Hz is consistent with the drop in the vibrational acceleration level in the high frequency band starting from around 3 kHz, which is observed in the frequency characteristics of ear cartilage shown in  FIG. 132  (B). 
     Further, in  FIG. 79 , in a frequency band from about 1 kHz to above 2 kHz, sound pressure in the non-contact state shown by the solid line and sound pressure in an unoccluded external auditory meatus state shown by the single-dotted line exhibit a tendency to increase or decrease in substantially identical directions, with respect to frequency change. In contrast to this, sound pressure in the non-contact state shown by the solid line and sound pressure in a occluded external auditory meatus state shown by the double-dotted line in  FIG. 79  exhibit a tendency to increase or decrease in opposite directions overall, with respect to frequency change. This means that the direct air-conducted sound component, which has strong effect from about 1 kHz to above 2 kHz, disappears upon closure of the entrance of the external auditory meatus, so that the effect of the frequency characteristics of ear cartilage, in which vibration transmission efficiency drops in the high frequency band, is expressed directly. As shown above, because the frequency characteristics of sound pressure in the unoccluded external auditory meatus state and the frequency characteristics of sound pressure in the occluded external auditory meatus state differ as a result of the frequency characteristics of ear cartilage shown in  FIG. 132(B) , there is a change in the quality of sound heard when the external auditory meatus is occluded. 
       FIG. 132(C)  further shows an image of equalization of the drive output to a piezoelectric bimorph element for the purpose of correcting the frequency characteristics of ear cartilage shown in  FIG. 132(B) . The solid line shows equalization performed in the unoccluded external auditory meatus state, and the dashed line equalization performed in the occluded external auditory meatus state. This equalization, as well as shifting between gain shown by the solid line and gain shown by the broken line, are performed by the cartilage conduction equalizer  8138  which is controlled by a controller  8139 . 
     As shown in  FIG. 132(C) , in the unoccluded external auditory meatus state, gain in the drive output is increased in the high frequency band from around 2500 Hz. Gain shift opposite in tendency from that in the frequency characteristics of ear cartilage shown in  FIG. 132(B)  with respect to frequency change is applied thereby, correcting the small difference between the non-contact state shown by the solid line and the contact state shown by the single-dotted line in  FIG. 79 . 
     In the high frequency band from around 2500 Hz, the effect of direct air conduction entering from the entrance of the external auditory meatus is large, whereas sound pressure produced by cartilage conduction is relatively small with respect thereto. Consequently, in cases in which this can be ignored, assuming the gain shown by the solid line in  FIG. 132(C)  to be flat, the eighty-six embodiment can be modified so as to perform equalization identical to equalization for ordinary direct air conduction. 
     In contrast to this, in the occluded external auditory meatus state shown by the dashed line in  FIG. 132(C) , in the high frequency band from around 2500 Hz, gain in the drive output is greatly elevated above that in the unoccluded external auditory meatus state shown by the solid line, as shown by an arrow. This corrects the frequency characteristics of sound pressure in the occluded external auditory meatus state, in which the effect of the frequency characteristics of ear cartilage are expressed directly, preventing changes in sound quality when the external auditory meatus is occluded. 
     As shown in  FIG. 132(B) , whereas ear cartilage exhibits a drop in vibrational acceleration level in a high frequency band starting from around 3 kHz, vibration per se is still possible, and therefore drop in sound pressure can be ameliorated by increasing the gain in the drive output in this frequency band. The extent to which to increase the gain is decided upon taking into consideration the fact that, in frequency band, the vibrational acceleration level of ear cartilage is low, and the efficiency with which sound pressure is increased despite increasing the drive output is poor. Moreover, because the sound signal sampling cycle in the telephone is 8 kHz and audio information above 4 kHz is absent from the outset, the fact that ear cartilage has frequency characteristics such that sound signals on the high-frequency band end are propagated with difficulty as shown in  FIG. 132(C)  does not pose a problem, and the principal components of the sound signal frequency band can be transmitted efficiently. By increasing the gain at the high-frequency end in a frequency band of 4 kHz and below in the aforedescribed manner, the sound quality of the sound signal can be improved. 
     The gain shift shown by the solid line and the dashed line in  FIG. 132(C)  may be performed automatically, for example, through detection by the pressure sensor  242  such as in the fifty-fourth embodiment. Alternatively, a microphone like the environment-noise microphone  4638  of the fiftieth embodiment could be furnished, switching automatically according to whether or not noise is greater than a predetermined level. In this case, on the assumption that, when noise is greater than a predetermined level, occlusion of the entrance of the external auditory meatus by the tragus or the like will have occurred with stronger pressing force against the ear cartilage naturally occurring as the user attempts to listen closely, the noise level at which automatic switching takes place may be set based on average values obtained through experimentation. 
     In preferred practice, the gain shifts shown by the solid line and the dashed line in  FIG. 132(C)  will be performed while employing a moving average value for pressure sensor output or environment-noise microphone output within a predetermined time interval, to avoid cumbersome shifting between the two. However, when the external auditory meatus becomes occluded, due to an earplug bone conduction effect (herein, the phenomenon designated thusly is the same as that known as the “external auditory meatus occlusion effect”), sound becomes louder, and there tends to be a noticeable change in sound quality; therefore, gain shifting may incorporate an element of hysteresis whereby, through a configuration in which shifting takes place relatively slowly, for example by performing gain shifts in a direction from the solid line to the dashed line in  FIG. 132(C)  rapidly in response to a detected increase in pressing force or environment noise, but holding back from performing gain shifts in a direction towards the solid line from the dashed line associated with softer sound, until change in a decreasing direction has been detected a predetermined number of times. 
       FIG. 133  is a flowchart showing functions of a controller  8139  the eighty-sixth embodiment of  FIG. 131 . The flow of  FIG. 133  primarily describes control of the cartilage conduction equalizer  8138 , and therefore operations centered on related functions have been extracted for illustration, and there are other operations of the controller  8139 , such as typical functions of mobile telephones and like, which are not represented in the flow of  FIG. 133 . While it is possible for the controller  8139  to concomitantly accomplish functions shown in various other embodiments, to avoid complexity, illustrations and descriptions of these functions as well have been omitted in  FIG. 133 . 
     The flow of  FIG. 133  starts when the main power source of the mobile telephone  8101  is turned on, and in Step S 452 , initial startup and a function check of each unit are performed, as well as initiating screen display on a display unit  205  of the mobile telephone  8101 . Next, in Step S 454 , the functions of the cartilage conduction unit (the cartilage conduction vibration unit  228 ) and the outgoing-talk unit (the outgoing-talk-processing unit  222 ) of the mobile telephone  8101  are turned off, and the routine advances to Step S 456 . 
     In Step S 456 , a check is performed to determine whether an earphone or the like has been inserted in the external earphone jack  8146 . Then, in the event that insertion into the external earphone jack  8146  is not detected, the routine proceeds to Step S 458 , in which a check is performed to determine whether short-range communication has been established with a mobile telephone accessory device, such as a headset, by a short-range communication unit  8147 . In the event this is not the case either, the routine proceeds to Step S 460 , and a check is performed to determine whether the current state is one in which another caller&#39;s answer to a telephone call request, or a call through mobile radio waves based on an incoming call, is in progress. When the current state is the talk state, the routine proceeds to Step S 462 , the cartilage conduction unit (the cartilage conduction vibration unit  228 ) and the outgoing-talk unit (the outgoing-talk-processing unit  222 ) are turned on, and routine proceeds to Step S 464 . 
     In Step S 464 , a check is performed to determine whether the current state is one an earplug bone conduction effect has occurred due to occlusion of entrance of the external auditory meatus, and in the event this is not the case, the routine advances to Step S 466 , then proceeds to Step S 468  without applying a signal in which the waveform of the user&#39;s own voice is inverted. The process of application/non-application of a waveform-inverted signal of the user&#39;s own voice has been described in Step S 52  to Step S 56  in the flow of  FIG. 10 , and therefore the details are omitted here. In Step S 468 , the equalization indicated by the solid line in  FIG. 132(C)  is established, and the routine advances to Step S 470 . The equalization performed in Step S 468  involves increasing the gain in drive output in the high-frequency band from around 2500 Hz, the equalization being premised on significant participation by direct-air conduction entering from the entrance of the external auditory meatus. As a modified embodiment, a configuration like that described above, in which equalization in Step S 468  and equalization for the purpose of ordinary direct air conduction are the same, would be acceptable. 
     On the other hand, when occurrence of an earplug bone conduction effect due to occlusion of the entrance of the external auditory meatus has been detected in Step S 464 , the routine advances to Step S 471 , applying a waveform-inverted signal of the user&#39;s own voice, as well as establishing equalization involving increased gain in drive output in the high-frequency band from around 2500 Hz in Step S 472 , and advances to Step S 470 . 
     In Step S 470 , a check is performed to determine whether the call has ended, and in the event this is not the case, returns to Step S 464 , repeating Step S 464  to Step S 472  for as long as the call has not ended. In so doing, equalization can be shifted between the solid line and the dash line of  FIG. 132(C)  in response to changes in settings or conditions during a call. On the other hand, in the event that the call is detected to have ended in Step S 470 , the routine advances to Step S 474 , the functions of the cartilage conduction unit (the cartilage conduction vibration unit  228 ) and the outgoing-talk unit (the outgoing-talk-processing unit  212 ) of the mobile telephone  8101  are turned off, and the routine proceeds to Step S 476 . When the talk state is not detected in Step S 460 , the routine advances directly to Step S 476 . 
     In contrast to this, when insertion into the external earphone jack  8146  has been detected in Step S 456 , or establishment of short-range communication with a mobile telephone accessory device has been detected in Step S 458 , the routine advances to Step S 478 . In Step S 478 , a check is performed in the same manner as in Step S 460 , to ascertain whether a call through mobile radio waves is in progress. In the event that the device is not currently in the talk state, the routine proceeds to Step S 480 , equalization for the purpose of normal air conduction is established, and the routine advances to Step S 482 . 
     In Step S 482 , a check is performed to determine whether the call has ended, and in the event this is not the case, returns to Step S 480 , repeating Step S 480  to Step S 482  for as long as the call has not ended. On the other hand, in the event that the call is detected to have ended in Step S 482 , the routine advances to Step S 476 . When the talk state is not detected in Step S 478 , the routine advances directly to Step S 476 . 
     In Step S 476 , a check is performed to determine whether or not the main power source of the mobile telephone  8101  has been turned off, and in the event the main power source is not off, the routine returns to Step S 456 , and thereafter repeats Step S 456  to Step S 482  for as long as turning off of the main power source is not detected in Step S 476 . In contrast to this, once it is detected in Step S 456  that the main power source has turned off, the flow terminates. 
       FIG. 134  is perspective views showing a modification example of the eighty-sixth embodiment shown in  FIG. 131 . For the description of  FIG. 134 , borrowing from  FIG. 110  (A) and  FIG. 100(B)  of the seventy-third embodiment which is similar in external appearance, common portions have been assigned the same reference numerals, and descriptions have been omitted.  FIG. 134(A)  is a front perspective view of the mobile telephone  8101 , and  FIG. 134(B)  is a back perspective view of the mobile telephone  8101 . In  FIG. 134 , unlike in the seventy-third embodiment, the in-camera  8117  is situated in an upper part of the mobile telephone  8101 . 
     In the modification example of the eighty-sixth embodiment shown in  FIG. 134 , the back surface of the mobile telephone  8101  is furnished with a pressing force sensing unit  8142  for detecting obstruction of the external auditory meatus, as shown in  FIG. 134(B) . This pressing force sensing unit  8142  is positioned at a location of spontaneous touching by the index finger of the hand when the mobile telephone  8101  is held against the ear by the user. When the user presses the mobile telephone  8101  forcefully against the ear to the extent that the external auditory meatus becomes obstructed, the intensity with which the index finger supporting this action presses against the pressing force sensing unit  8142  increases. Obstruction of the external auditory meatus is thereby detected on the basis of the output of the pressing force sensing unit  8142 . 
     In order to avoid unintentional operation, as shown in  FIG. 134(A) , the upper part of the mobile telephone  8101  is furnished with a pair of infrared light-emitting units  8119 ,  8120  constituting proximity sensors for detecting that the mobile telephone  8101  is contacting the ear for the purpose of a call, and a common infrared light proximity sensor  8121  for picking up reflected infrared light from the ear. In so doing, the pressing force sensing unit  8142  is functional only when the mobile telephone  8101  is contacting the ear, so that in the event that the user applies force to the pressing force sensing unit  8142  while, for example, looking at the display screen  6905  or the like, the mobile telephone  8101  will not react. 
     The pressing force sensing unit  8142  is furnished near a central portion thereof with a pressure-sensitive protrusion  8142   a , not only as a means for detecting when the intensity of spontaneous pressing by the index finger exceeds as predetermined level, but also to enable intentional pressing operations thereof. In this way, the pressing force sensing unit  8142  can also function as a manual switch for equalization switching. 
     Eighty-Seventh Embodiment 
       FIG. 135  is a block diagram relating to an eighty-seventh embodiment according to an aspect of the present invention, configured as a typical mobile telephone  1601  and a headset  8281  capable of short-range communication therewith.  FIG. 135  has much in common with the seventeenth embodiment of  FIG. 29 , and therefore the same reference numerals are assigned to the common portions, omitting descriptions unless necessary. 
     The eighty-seventh embodiment of  FIG. 135  differs from the seventeenth embodiment of  FIG. 29  in that the headset  8281  has a cartilage conduction equalizer  8238  controlled by a controller  8239 . The cartilage conduction equalizer  8238  has functions resembling those of the cartilage conduction equalizer  8138  of the eighty-sixth embodiment of  FIG. 131 , and adopts a piezoelectric bimorph element having frequency characteristics in common with that shown in  FIG. 132(A) , as a vibration source for a cartilage conduction vibration unit  1626 . The device is configured to perform the equalization shown in  FIG. 132  (C), in order to handle the frequency characteristics of ear cartilage shown in  FIG. 132(B) . Switching between the solid line and the dashed line of  FIG. 132(C)  is performed on the basis of detection by a bending detection unit  1588 . 
     In the eighty-seventh embodiment of  FIG. 135 , the sound signal on which equalization on the premise of normal air conduction has been performed is transmitted to the headset  8281  by the mobile telephone  1601  from the short-range communication unit  1446 . The headset  8281  is configured to have the cartilage conduction vibration unit  1626 , and therefore the equalization shown in  FIG. 132(C)  is performed by the cartilage conduction equalizer  8238 , on the basis of the received sound signal. 
     Returning to the eighty-sixth embodiment of  FIG. 86  to supplement the description, when insertion of the external earphone jack  8146  has been detected in Step S 456  of the flowchart of  FIG. 133 , or when establishment of short-range communication with a mobile telephone accessory device has been detected in Step S 458 , normal air equalization is performed. The reason for doing so is that the device is assumed to be compatible with normal air type earphones and headsets or, in the case of a cartilage conduction type headset, to be paired with a headset which is itself provided with the cartilage conduction equalizer  8238 , as in the eighty-seventh embodiment of  FIG. 135 . 
     Eighty-Eighth Embodiment 
       FIG. 136  is a perspective view and cross sectional views relating to an eighty-eighth embodiment according to an aspect of the present invention, configured as a mobile telephone  8201 . A feature of the eighty-eighth embodiment resides in the structure of the cartilage conduction unit, and therefore the description shall center thereon; configurations shown in the other embodiments can be adopted, as appropriate, for the other portions, so illustrations and descriptions of these are omitted.  FIG. 136(A)  is a front perspective view of the eighty-eighth embodiment. The configuration of chassis of the mobile telephone  8201  is one in which a front panel  8201   a  of plastic or the like and a back panel  8201   b  of plastic or the like sandwich a metal frame. The metal frame is divided into an upper frame  8227 , a right frame  8201   c , a lower frame  8201   d , and a left frame  8201   e  (not visible in  FIG. 136(A) ), with elastic bodies  8201   f  respectively interposed therebetween. The front panel  8201   a  is furnished with a window for a large-screen display unit  8205 , and with a window for a microphone  8223  and a window for an in-camera  8017 . 
     At an inside center part of the upper frame  8227  an electromagnetic vibrator  8225  serving as a cartilage conduction vibration source is anchored in such a way as to vibrate in a direction perpendicular to the front panel  8201   a . The electromagnetic vibrator  8225  has substantially no contact with parts other than the upper frame  8227 , so vibration of the electromagnetic vibrator  8225  is propagated only to the upper frame  8227 . Vibration of the electromagnetic vibrator  8225  propagated to the center part of the upper frame  8227  is transmitted to a right side corner part  8224  and a left side corner part  8226  of the electromagnetic vibrator  8225 , which serve as cartilage conduction units. In this way, according to the eighty-eighth embodiment, the metal upper frame  8227  is concomitantly employed for cartilage conduction, and in the same manner as in other embodiments, upper corner parts at the left and right of the chassis of the mobile telephone  8201  (the right side corner part  8224  and the left side corner part  8226 ) function as cartilage conduction units. However, in the eighty-eighth embodiment, in the same manner as in the fourth embodiment of  FIG. 7 , the upper frame  8227  does not vibrate solely at the right side corner part  8224  at the right edge and the left side corner part  8226  at the left edge, but rather vibrates in its entirety, whereby audio information can be transmitted regardless of which part of the inside upper edge side of the mobile telephone  8201  is placed against the ear cartilage. This will be discussed in detail below. 
     The configuration of the eighty-eighth embodiment is properly described as one whereby, when the inside upper edge of the mobile telephone  8201  is placed against the ear cartilage, an area proximate to the upper edge of the front panel  8201   a  actually contacts the ear cartilage. That is, vibration of the upper frame  8227  (including the right side corner part  8224  and the left side corner part  8226 ) is propagated to an area proximate to the upper edge part of the front panel  8201   a , from whence it is transmitted to the ear cartilage. Moreover, as vibration of the upper frame  8227  entails vibration of an area proximate to the upper edge part of the front panel  8201   a  over a relatively large surface area, required air conduction is generated from the upper edge part of the front panel  8201   a  as well. The eighty-eighth embodiment can be said to share this feature in common with the tenth embodiment of  FIG. 19 . Specifically, the electromagnetic vibrator  8225  serves as the cartilage conduction vibration source, and concomitantly as a drive source for the incoming-call unit, for generating sound waves which are propagated to the eardrum through ordinary air conduction. Consequently, in the same manner as in other embodiments, it is possible to make calls in a manner benefiting from the advantages of cartilage conduction, in a style in which an upper corner part of the mobile telephone  8201  placed against the ear cartilage, such as the tragus; while at the same time it is possible to make calls in the ordinary style, i.e., with the vicinity of an upper edge center part of the mobile telephone  8201  placed against the ear. Further, because the upper edge part of the front panel  8201   a  vibrates over a relatively wide surface area in the aforedescribed manner, air-conducted sound can be generated at the required level from an ordinary mobile telephone, even one not furnished with an incoming-call unit that relies on air conduction, such as a speaker. The details of this will be discussed below. 
     Moreover, due to being isolated from the right frame  8201   c  and the left frame  8201   e  by the elastic bodies  8201   f , transmission of vibration the upper frame  8227  to the lower part of the chassis is suppressed, so in the same manner as in other embodiments, the vibration energy of the electromagnetic vibrator  8225  serving as the cartilage conduction vibration source can be efficiently contained within the upper frame  8227 . Vibration of the upper frame  8227 , by virtue of the contact thereof with the front panel  8201   a  in the aforedescribed manner, is manifested as vibration over a relatively wide surface area in the vicinity of an upper edge thereof. However, vibration of a lower part of the front panel  8201   a  is suppressed by the right frame  8201   c , the lower frame  8201   d , and the left frame  8201   e  which, due to the interposed elastic bodies  8201   f , have low vibration transmission, whereby vibration of the front panel  8201   a  is reduced in the course of traveling downward (through a portion including the large-screen display unit  8205 ), where sound generation is unwanted. 
     The upper frame  8227  also concomitantly performs the function of the antenna  5345  of the telephone function unit shown in the fifty-seventh embodiment of  FIG. 87 . In specific terms, the antenna  5345  includes a transmission antenna and a reception antenna; in the eighty-eighth embodiment of  FIG. 136 , the upper frame  8227  which serves as a cartilage conduction unit is employed concomitantly as an antenna for reception as well. 
     Further, an external earphone jack  8246  like that in the eighty-fourth embodiment of  FIG. 127  is anchored to the upper frame  8227 . In so doing, the upper frame  8227  can be furnished with the external earphone jack  8246  by means of a structure of utmost simplicity. In the aforedescribed structure, when the upper frame  8227  vibrates, the external earphone jack  8246  will vibrate as well; however, when an external earphone plug has been inserted into the external earphone jack  8246 , this is detected, whereby vibration of the upper frame  8227  is halted. Consequently, in a state in which cartilage conduction is propagated to ear cartilage, vibration of the external earphone jack  8246  does not pose a problem because no external earphone plug is inserted, whereas when an external earphone plug is inserted, vibration of the upper frame  8227  is halted, so there is no problem in this case either. Likewise, when the upper frame  8227  vibrates, this vibration is propagated to the in-camera  8017  as well via internal structures and the front panel  8201   a  or the like, but when the device is in videoconferencing mode using the in-camera  8017 , vibration of the upper frame  8227  is halted, and therefore there is no problem in this case either. 
     Further, a power switch  8209  is situated on the upper frame  8227 . To make it possible to slide the power switch  8209  up and down with respect to the upper frame  8227 , it is positioned within a window in the upper frame  8227 , leaving a small gap, so as to not contact the upper frame  8227 . In so doing, when the upper frame  8227  vibrates, the vibration thereof will not be propagated to the power switch  8209 , nor will the inside edge of the window of the vibrating upper frame  8227  strike or chatter against the power switch  8209 . 
       FIG. 136(B)  is a B 1 -B 1  cross sectional view of  FIG. 136(A) , in which identical portions are assigned the same reference numerals, omitting discussion thereof unless necessary. As will be clear from  FIG. 136(B) , the electromagnetic vibrator  8225  is anchored to an inside center part of the upper frame  8227 , and connected to a driver circuit terminal by a flexible connector cable  8225   a . Moreover, as will be clear from  FIG. 136(B) , the electromagnetic vibrator  8225  has substantially no contact with parts other than the upper frame  8227 . Further, because the elastic bodies  8201   f  have been respectively interposed between the upper frame  8227 , the right frame  8201   c , and the left frame  8201   e , transmission of vibration of the upper frame  8227  to the lower part of the chassis is suppressed. In this way, the upper frame  8227  may be employed concomitantly in suitable fashion as a cartilage conduction unit. 
     As will be clear from  FIG. 136(B) , the upper frame  8227  is connected to an antenna terminal of the telephone function unit by a flexible connector cable  8227   a , and thereby employed concomitantly as a reception antenna. Moreover, the external earphone jack  8246  is anchored to the upper frame  8227 , and connected to an external output circuit terminal by a flexible connector cable  8246   a . The upper frame  8227  is moreover furnished with a window for placement of the power switch  8209 , making it possible for the power switch  8209 , which has been furnished to a waterproof power switch unit  8209   a , to move up and down without contacting the upper frame  8227  due to a small gap relative to the inner edge of the window. The waterproof power switch unit  8209   a  is supported by an internal structure  8209   b , and connected to a controller terminal by a wire  8209   c . A waterproof packing is sandwiched between the inside edge of the window of the upper frame  8227  and the waterproof power switch unit  8209   a , making it possible for the upper frame  8227  to vibrate independently of the waterproof power switch unit  8209   a , as well as to prevent water from infiltrating between the two. 
       FIG. 136(C)  is a top view of  FIG. 136(A) , in which identical portions are assigned the same reference numerals, omitting discussion thereof unless necessary. As will be clear from  FIG. 136(C) , an upper edge of the front panel  8201   a  and an upper edge of the back panel  8201   b  are configured to sandwich the upper frame  8227 . The external earphone jack  8246  and the power switch  8209  are exposed on the upper frame  8227 . 
       FIG. 136(D)  is the B 2 -B 2  cross sectional view shown in  FIG. 136(A)  to  FIG. 136  (C), in which identical portions are assigned the same reference numerals, omitting discussion thereof unless necessary. As will be clear from  FIG. 136(D) , the front panel  8201   a  and the back panel  8201   b  are configured to sandwich the upper frame  8227 . The electromagnetic vibrator  8225  is anchored to the inside center part of the upper frame  8227 . As will be clear from  FIG. 136(D) , the electromagnetic vibrator  8225  has substantially no contact with any parts other than the upper frame  8227 . 
       FIG. 136(E)  is the B 3 -B 3  cross sectional view shown in  FIG. 136(B) , in which identical portions are assigned the same reference numerals, omitting discussion thereof unless necessary. As will be clear from  FIG. 136(E) , the front panel  8201   a  and the back panel  8201   b  are configured to sandwich a right corner part  8224  of an edge part of the upper frame  8227 . As will be clear from  FIG. 136(E) , an elastic body  8201   f  is interposed between the right corner part  8224  of the edge part of the upper frame  8227  and the right frame  8201   c , suppressing transmission of vibration of the upper frame  8227  (including the right corner part  8224 ) to the lower part of the chassis (including the right frame  8201   c ). 
       FIG. 137  is side views of the mobile telephone  8201 , describing a talk state in the eighty-eighth embodiment of  FIG. 136 .  FIG. 137(A)  is a view substantially similar to  FIG. 2(A)  shown in the first embodiment, and shows the mobile telephone  8201  placed against the right ear  28  while held in the right hand. Like  FIG. 2 ,  FIG. 137(A)  is a view of the face seen from the right side, in which the back surface side (the rear side in  FIG. 136(A) ) of the mobile telephone  8201  is visible. As in  FIG. 2 , the mobile telephone  8201  is shown by single-dotted lines in order to depict the relationship of the mobile telephone  8201  and the right ear  28 . 
     In the mobile telephone  8201  of the eighty-eighth embodiment, the entire upper frame  8227  vibrates, and in the talk state of  FIG. 137(A) , as in  FIG. 2(A) , the right corner part  8224  contacts the left ear  28  in proximity to the tragus, whereby the advantages of cartilage conduction during a call are realized in the same manner as in other embodiments. 
     In contrast to this,  FIG. 137(B)  shows a call being made in the ordinary style, with an area proximate to the upper edge center part of the mobile telephone  8201  pressed against the ear. At this time as well, because a relatively long area  8227   b  in a center portion of the upper frame  8227  contacts the cartilage surrounding the entrance of the external auditory meatus, talk through the agency of cartilage conduction is possible. Further, as described previously, because the upper edge part of the mobile telephone  8201  vibrates through a relatively wide surface area, air-conducted sound can be generated at the required level from an ordinary mobile telephone. Consequently, in the talk state as in  FIG. 137(B) , talk is possible through the agency of cartilage conduction from the center portion of the upper frame  8227 , and through the agency of air-conducted sound entering through the entrance of the external auditory meatus. An air-conducted sound component entering through the entrance of the external auditory meatus is present in the talk state shown in  FIG. 137(A)  as well, but the proportion thereof is greater in  FIG. 137(B) . 
     The mobile telephone  8201  of the eighty-eighth embodiment shares in common with other embodiments the fact that the advantages of cartilage conduction can be utilized to the maximum in the call style shown in  FIG. 137(A) . However, with the mobile telephone  8201  of the eighty-eighth embodiment, when used as shown in  FIG. 137(B) , whether out of user preference or a misunderstanding of how the device should be used, the device can nevertheless be used without any problem as an ordinary mobile telephone, and air-conducted sound can be generated at the required level, even when the device is not furnished with an incoming-call unit that relies on air conduction, such as a speaker, and as such is a commercially viable configuration meeting specifications for an ordinary mobile telephone. 
     While  FIG. 137  describes the case of use with the right ear, in the case of using the mobile telephone  8201  with the left ear, in exactly the same manner, use in a style with the left corner part  8226  placed in contact with an area proximate to the tragus of the left ear, as well as talk in the ordinary style with the upper center part of the mobile telephone  8201  pressed against the ear, are possible. 
       FIG. 138  is cross sectional views showing modification examples of the eighty-eighth embodiment of  FIG. 136 . The modification examples relate to configurations whereby vibration energy may be further concentrated in the proximity to the upper edge of the front panel  8201   a  which actually contacts the ear cartilage when the inside upper edge of the mobile telephone  8201  is pressed against the ear cartilage.  FIG. 138(A)  is exactly the same as  FIG. 136(E) , and is illustrated again for reference. Consequently,  FIG. 138(A)  is the B 3 -B 3  cross section in  FIG. 136(B) , in which the upper frame  8227  and the right corner part  8224  thereof are visible in cross section. The modification examples are configured such that upper edge-proximate portions of the front panel  8201   a  and the back panel  8201   b  are thinner than other portions, thereby modifying the width and shape of the right corner part  8224 , but in the modification examples, the cross section proximate to the upper edges of the front panel  8201   a  and the back panel  8201   b , and the width of the upper surface of the upper frame  8227 , in both the left corner part  8226  and the center part are identical to those in the right corner part  8224 . 
       FIG. 138(B)  is configured such that an upper edge-proximate portion  8201   g  of the front panel  8201   a  is thinner than other portions, and likewise for the back panel  8021   b  as well, an upper edge-proximate portion  8201   h  thereof is thinner than other portions. In correspondence therewith, the width of the right corner part  8224   a  of the upper frame  8227  is greater than that of a right frame  8201   i . In association with this, the cross section of an elastic body  8201   j  is trapezoidal so as to connect the two. By configuring the upper edge-proximate portion  8201   g  of the front panel and the upper edge-proximate portion  8201   h  of the back panel  8201   b , which contact the vibrating upper frame  8227  in this way, to respectively be thinner than other portions, these upper edge-proximate portions vibrate more easily, and better propagate vibration of the upper frame  8227 . The lower parts of the front panel  8201   a  and the back panel  8201   b  are more resistant to vibration, due to the difference in thickness. 
       FIG. 138(C)  is configured such that the inside of an upper edge-proximate portion  8201   k  of the front panel  8201   a  has a tapered shape becoming thinner towards the top, and likewise in the back panel  8021   b  as well, the inside of an upper edge-proximate portion  8201   m  thereof has a tapered shape becoming thinner towards the top. In association with this, a right corner part  8224   b  of the upper frame  8227  is trapezoidal. With this configuration as well, the upper edge-proximate portion  8201   k  of the front panel  8201   a  and the upper edge-proximate portion  8201   m  of the back panel  8201   b  which contact the vibrating upper frame  8227  vibrate more easily, and better propagate vibration of the upper frame  8227 . The lower parts of the front panel  8201   a  and the back panel  8201   b  are more resistant to vibration, due to their increasing thickness in the downward direction. 
       FIG. 138(D)  is configured such that the outside of an upper edge-proximate portion  8201   n  of the front panel  8201   a  has a tapered shape becoming thinner towards the top, and likewise in the back panel  8021   b  as well, the outside of an upper edge-proximate portion  8201   p  thereof has a tapered shape becoming thinner towards the top. With this configuration as well, the upper edge-proximate portion  8201   n  of the front panel  8201   a  and the upper edge-proximate portion  8201   p  of the back panel  8201   b  which contact the vibrating upper frame vibrate more easily, and better propagate vibration of the upper frame  8227 . The lower parts of the front panel  8201   a  and the back panel  8201   b  are more resistant to vibration, due to their increasing thickness in the downward direction. 
     The various features of the embodiments described above are not limited to implementation in the aforedescribed embodiments, and may be implemented in other embodiments as well, provided that the advantages thereof can be enjoyed by doing so. For example, in the eighty-eighth embodiment, the cartilage conduction vibration source was configured as an electromagnetic vibrator. An electromagnetic vibrator is suited to in layouts which members are closely packed on the upper part of a mobile telephone. However, the cartilage conduction vibration source adopted in the eighty-eighth embodiment is not limited to one of electromagnetic type, and a piezoelectric bimorph element like those shown in other embodiments, for example, would be acceptable. 
     Eighty-Ninth Embodiment 
       FIG. 139  is a system configuration diagram of an eighty-ninth embodiment of an aspect according to the present invention. The eighty-ninth embodiment is configured as a headset for use as an outgoing-talk/incoming-talk unit for a mobile telephone, which, together with an ordinary mobile telephone  1401 , makes up a mobile telephone system. In the eighty-ninth embodiment, as in the twenty-fourth embodiment of  FIG. 37 , a cartilage conduction unit is situated at a location touching an anterior region at the outside  1828  of the cartilage of the base of the ear  28  (the mastoid side of the auricle attachment region), and a headset  8381  incorporating the cartilage conduction unit is capable of communicating with the ordinary mobile telephone  1401  through a short-range communication unit  8387  such as a Bluetooth™ device or the like. Consequently, portions in common with  FIG. 37  have been assigned common reference numbers, and descriptions thereof are omitted. Also, reference numbers have not been assigned to the mobile telephone  1401  portions. 
       FIG. 139(A)  is a side view showing a relationship of the headset  8381  and the ear  28  in the eighty-ninth embodiment. As will be clear from  FIG. 139(A) , the headset  8381  of the eighty-ninth embodiment comprises an ear-hook unit  8382  incorporating the cartilage conduction unit, and headset body  8384 , the two being connected by a detachable cable  8381   a . The headset body  8384  has a microphone  8323  or the like, and clips to a breast pocket or the like. In  FIG. 139(A) , to avoid complexity while providing a clear overview of the interrelationships, the ear  28  is depicted by solid lines, and the ear-hook unit  8382  for hooking onto the outside  1828  of the base thereof is depicted by imaginary lines, with the internal configuration omitted. 
     In contrast to this,  FIG. 139(B)  is a system configuration diagram from which illustration of the ear, except for the entrance of the external auditory meatus (the earhole)  232 , has been omitted, and which shows the details of the headset  8381  of the eighty-ninth embodiment, together with the mobile telephone  1401 . Portions identical to those in  FIG. 139(A)  have been assigned the same reference numerals. The ear-hook unit  8382 , shown in cross section in  FIG. 139(B) , is constituted of elastic material of acoustic impedance approximating that of ear cartilage. As will be clear from  FIG. 139(B) , the inner edge of the ear-hook unit  8382  constitutes a contact part for linear contact hooked around the base of the ear  28  along the outside  1828  thereof. A holding part  8325   a  made of hard material is furnished in proximity to a portion closest to the external auditory meatus entrance (the earhole)  232 , at the outside  1828  of the cartilage of the base of the ear  28 , with one end of a piezoelectric bimorph element  8325  being supported in cantilever fashion by this holding part  8325   a.    
     As will be clear from  FIG. 139(B) , the piezoelectric bimorph element  8325  does not contact the interior of the ear-hook unit  8382  in any portion thereof other than the support part  8325   a , whereby the other end side (connection terminal side) of the piezoelectric bimorph element  8325  vibrates freely, the counteraction thereof being transmitted as vibration to the support part  8325   a . Vibration of the support part  8325   a  is then transmitted from the inner edge of the ear-hook unit  8382  to the outside  1828  of the base of ear  28  in linear contact therewith, this vibration producing air-conducted sound from the external auditory meatus inner wall through the agency of the cartilage surrounding the external auditory meatus opening, which sound is transmitted to the eardrum. The outside  1828  of the cartilage of the base of ear is close to the external auditory meatus entrance  232  to the inside thereof, providing suitable conditions for producing air conduction in the external auditory meatus interior, from the cartilage surrounding the external auditory meatus opening. 
     Meanwhile, the headset body  8384  has the short-range communication unit  8387  such as a Bluetooth™ device or the like, which is capable of communicating with the mobile telephone  1401 . A sound signal received by radio waves  1285  through the short-range communication unit  8387  from the mobile telephone  1401  is presented from a sound unit  8336  to an amplifier  8340  via an acoustic processing circuit  8338 . The amp  8340  drives the piezoelectric bimorph element  8325  from a connector  8346  via a cable  8381   a . A sound signal picked up by the microphone  8323  is transmitted to the mobile telephone  1401  from the short-range communication unit  8387  by the radio waves  1285  via the sound unit  8336 . A controller  8339  controls the short-range communication unit  8387 , the acoustic processing circuit  8338 , and the sound unit  8336 , as well as transmitting operation signals from an operating unit  8309  to the mobile telephone  1401  from the short-range communication unit  8387 . A power supply unit  8348  including a rechargeable cell supplies power to the entire headset  8381 . 
     In the preceding eighty-ninth embodiment, the piezoelectric bimorph element  8325  for cartilage conduction is situated in the ear-hook unit  8382  while the microphone  8323  is situated in the headset body  8384 , the two being separated from one another and connected only by the flexible cable  8381   a , so that the microphone  8323  is unaffected by vibration of the piezoelectric bimorph element  8325 . Moreover, in the eighty-ninth embodiment, vibration for the purpose of cartilage conduction is transmitted from the rear side of the ear  28 , and therefore the external auditory meatus entrance (the earhole)  232  is completely free, so entry of sounds, such as a car horn, into the ear in an emergency situation is unimpeded, nor is there the discomfort associated with inserting an earphone or the like into the external auditory meatus entrance (the earhole)  232 . An external auditory meatus occluding effect can readily be obtained by covering the ear  28  with the hand in order to enhance the cartilage conduction effect, whereby increased volume and blockage of outside noise can be achieved. 
     In  FIG. 139 , for simplicity, only one ear-hook unit  8382 , that for the right ear, is illustrated; however, it would be possible for an ear-hook unit of similar configuration for the left ear to be connected in common to the headset body  8384 , and the respective ear-hook units hooked on both ears to afford a stereo reception unit. In so doing, ordinary calls are easier to hear, and the configuration is one suited to enjoyment of music as well. 
     Ninetieth Embodiment 
       FIG. 140  is a system configuration diagram of a ninetieth embodiment of an aspect according to the present invention. The ninetieth embodiment is likewise configured as a headset for use as an outgoing-talk/incoming-talk unit for a mobile telephone, which, together with the ordinary mobile telephone  1401 , makes up a mobile telephone system. In the ninetieth embodiment, as in the eighty-ninth embodiment of  FIG. 139 , a cartilage conduction unit is situated at a location touching an anterior region at the outside  1828  of the cartilage of the base of the ear  28 , and a headset  8481  incorporating the cartilage conduction unit is capable of communicating with the ordinary mobile telephone  1401  through a short-range communication unit  8487  such as a Bluetooth™ device or the like. Consequently, portions in common with  FIG. 139  have been assigned common reference numbers, and descriptions thereof are omitted. 
       FIG. 140(A)  is a side view showing a relationship of the headset  8481  and the ear  28  in the ninetieth embodiment. As will be clear from  FIG. 140(A) , a point of difference between the ninetieth embodiment and the eighty-ninth embodiment of  FIG. 139  is that the headset  8481  is configured as an integrated unit. That is, in the ninetieth embodiment, the microphone and other configurations are situated within the headset  8481 . In  FIG. 140(A) , adopting the same convention as in the eighty-ninth embodiment, the ear  28  is shown by solid lines, and the ear-hook unit  8482  for hooking onto the outside  1828  of the base thereof is depicted by imaginary lines, with the internal configuration omitted. 
     In contrast to this,  FIG. 140(B) , like  FIG. 139(B) , is a system configuration diagram from which illustration of the ear  28 , except for the entrance of the external auditory meatus (the earhole)  232 , has been omitted, and which shows the details of the headset  8481  of the ninetieth embodiment, together with the mobile telephone  1401 . Portions identical to those in  FIG. 140(A)  have been assigned the same reference numerals. The headset  8481 , shown in cross section in  FIG. 140(B) , has the ear-hook unit  8482  constituted of elastic material, the inner edge of which constitutes a contact part for linear contact while hooked around the base of the ear  28  along the outside  1828  thereof. Moreover, as in the eighty-ninth embodiment, a piezoelectric bimorph element  8325  is supported at one end in cantilever fashion by a holding part  8482   a  situated closest to the external auditory meatus entrance (the earhole)  232 , at the outside  1828  of the cartilage of the base of the ear  28 . 
     As will be clear from  FIG. 140(B) , in the ninetieth embodiment as well, the piezoelectric bimorph element  8425  does not contact the interior of the ear-hook unit  8482  in any portion thereof other than the support part  8482   a , whereby the other end side (connection terminal side) of the piezoelectric bimorph element  8425  vibrates freely, the counteraction thereof being transmitted as vibration to the support part  8482   a . Vibration of the support part  8482   a  is then transmitted in the same manner as in the eighty-ninth embodiment, from the inner edge of the ear-hook unit  8482  to the outside  1828  of the base of ear  28  in linear contact therewith, this vibration producing air-conducted sound from the external auditory meatus inner wall through the agency of the cartilage surrounding the external auditory meatus opening, which sound is transmitted to the eardrum. 
     An upper part of the ear-hook unit  8482  is continuous with an anterior part  8484  comprising the same hard material, and situated across a gap  8481   b  therefrom. The anterior part  8484  is furnished with the short-range communication unit  8487  such as a Bluetooth™ device or the like, capable of communicating with the mobile telephone  1401 . A sound signal received by the short-range communication unit  8487  by radio waves  1285  from the mobile telephone  1401  is presented from a sound unit  8436  to an amplifier  8440  via an acoustic processing circuit  8438 , in an arrangement identical to the eighty-ninth embodiment. The amp  8440  drives the piezoelectric bimorph element  8425  through a cable  8481   a  passing from the anterior part  8484  and through a connecting part to the ear-hook unit  8482 . While omitted from the illustration in  FIG. 140(B) , the ninetieth embodiment also has a controller and an operating unit analogous to those in the eighty-ninth embodiment. 
     The microphone  8423 , which is furnished to a distal end of an extension part  8481   c  a considerable distance below a portion connecting to the ear-hook unit  8482 , is connected to the sound unit  8486 . In so doing, sound signals picked up by the microphone  8423  are transmitted to the mobile telephone  1401  by the radio waves  1285 , from the short-range communication unit  8487  via the sound unit  8436 . 
     A rechargeable cell  8485  of a power supply unit for supplying power to the headset  8481  as a whole is situated intervening between the ear-hook unit  8482  and the extension part  8481   c  within the anterior part  8484 . According to the ninetieth embodiment, the headset  8481  is of integrated configuration, and therefore vibration of the piezoelectric bimorph element  8425  is propagated to the anterior part  8484  from the ear-hook unit  8482 . However, due to the cell  8485  being situated in the aforedescribed manner, vibration of the anterior part  8484  is suppressed midway by weight of the cell  8485 , and the vibration component transmitted to the extension part  8481   c  is small. Consequently, the effects of vibration of the piezoelectric bimorph element  8425  on the microphone  8423  are minimal. 
     Ninety-First Embodiment 
       FIG. 141  is cross sectional views and a block diagram relating to a ninety-first embodiment according to an aspect of the present invention, configured as a stereo headphone system  8581 . The ninety-first embodiment is based on the sixty-third embodiment of  FIG. 95 , and therefore descriptions of elements common to both are omitted to the greatest possible extent, focusing the description on the elements being added.  FIG. 141(A)  shows a cross sectional view of the entirety of the stereo headphone system  8581  which is similar to the sixty-third embodiment. The stereo headphone system  8581  has a right-ear cartilage conduction unit  8524  and a left-ear cartilage conduction unit  8526 , which respectively are conical (cone)-shaped convex shapes. Piezoelectric bimorph elements  8525   a  and  8525   b  are respectively attached such that the vibrating surface side thereof contacts the unit.  FIG. 141  (A) also shows a block diagram of a sound signal source unit  8584  in the headphone system  8581 , for better understanding of the system in its entirety. 
     An added feature of the ninety-first embodiment resides in passage holes  8524   a  and  8526   a  which are respectively furnished at the center in the right-ear cartilage conduction unit  8524  and the left-ear cartilage conduction unit  8526 , a configuration that allows outside air-conducted sound to reach the eardrum from the external auditory meatus entrance even while the headphone system  8581  is being worn. The system is further furnished with shutters  8558  and  8559  driven by shutter drive units  8557   a  and  8557   b , whereby the passage holes  8524   a  and  8526   a  may be respectively occluded as needed, so that an external auditory meatus occluding effect can be obtained. In  FIG. 141(A) , the passage holes  8524   a  and  8526   a  are depicted in the unoccluded state. 
     A sound signal output from an acoustic processing circuit  8538  of the sound unit  8584  drives the piezoelectric bimorph elements  8525   a  and  8525   b  via a stereo amp  8540 , the vibration thereof being propagated to the inner wall of the external auditory meatus entrance by the right-ear cartilage conduction unit  8524  and the left-ear cartilage conduction unit  8526 , giving rise to good cartilage conduction. The sound unit  8584  is further furnished with a shutter control unit  8539 , and when outside noise at or above a predetermined level is detected by a noise detection unit  8541 , or when manually-operated unit  8509  is manually operated as needed, an occlusion signal is presented to the shutter drivers  8557   a  and  8557   b , whereby the shutters  8558  and  8559  slide, and respectively occlude the passage holes  8524   a  and  8526   a . On the other hand, when the noise detection unit  8541  does not detect outside noise at or above a predetermined level, or when the manually-operated unit  8509  is manually operated once more, an unocclusion signal is presented to the shutter drivers  8557   a  and  8557   b , whereby the shutters  8558  and  8559  slide, and the passage holes  8524   a  and  8526   a  are respectively unoccluded. 
       FIG. 141(B)  and  FIG. 141(C)  are enlarged fragmentary views of  FIG. 141(A) , showing opening and closing of the aforedescribed shutters. Identical portions have been assigned the same reference numerals. For simplicity, only the right-ear cartilage conduction unit  8524  is illustrated, but the left-ear cartilage conduction unit  8526  is similar in design.  FIG. 141(B)  is the same as  FIG. 141(A) , showing the passage hole  8524   a  in the unoccluded state. In contrast to this,  FIG. 141(C)  shows the shutter  8558  slid upwards, occluding the passage hole  8524   a . In so doing, in the state shown in  FIG. 141(B) , while obtaining cartilage conduction, it is possible at the same time for outside air-conducted sound to be transmitted to the eardrum from the external auditory meatus opening  30   a . In the state shown in  FIG. 141(C)  on the other hand, an external auditory meatus occlusion effect may be obtained in cartilage conduction. According to the configuration of the ninety-first embodiment as above, appropriate external auditory meatus occlusion effect may be obtained automatically, or through hand operation, without having to press the cartilage conduction unit or block the ear with the hand. 
     The various features of the embodiments described above are not limited to implementation in the aforedescribed embodiments, and may be implemented in other aspects as well, provided that the advantages thereof can be enjoyed by doing so. For example, the advantages of a configuration in which an external auditory meatus occlusion effect is obtained through occlusion and unocclusion of the external auditory meatus entrance by shutters as shown in the ninety-first embodiment are not limited to cases of cartilage conduction. Specifically, in the case of ordinary bone conduction as well, it is possible for appropriate external auditory meatus occlusion effect to be obtained automatically, or through hand operation, without having to block the ear with the hand. 
     In the eighty-ninth embodiment and the ninetieth embodiment, piezoelectric bimorph elements were adopted as the cartilage conduction vibration sources, but it would be possible to employ vibrators of electromagnetic type instead. In this case, the electromagnetic vibrator would suitably be situated in proximity to a portion closest to the external auditory meatus entrance (the earhole)  232 , at the outside  1828  of the cartilage of the base of the ear  28  (a location equivalent to that of the holding part  8325   a  of  FIG. 139 ). 
     Ninety-Second Embodiment 
       FIG. 142  is a system configuration diagram of a ninety-second embodiment of an aspect according to the present invention. The ninety-second embodiment is configured as a headset for use as an outgoing-talk/incoming-talk unit for a mobile telephone, which, together with the ordinary mobile telephone  1401 , makes up a mobile telephone system. In the ninety-second embodiment, as in the ninetieth embodiment of  FIG. 140 , a cartilage conduction unit is situated at a location touching an anterior region at the outside  1828  of the cartilage of the base of the ear  28 , and a headset  8681  incorporating the cartilage conduction unit is capable of communicating with the ordinary mobile telephone  1401  through a short-range communication unit  8487  such as a Bluetooth™ device or the like. As  FIG. 142  has much in common with  FIG. 140 , corresponding portions have been assigned common reference numbers, and descriptions thereof are omitted. 
     A point of difference between the ninety-second embodiment and the ninetieth embodiment of  FIG. 140  is the use of a contact microphone  8623  placed in direct contact against the head or the like of the user to sense vibration thereof, rather than an air-conduction microphone, for picking up audio. As shown in side view in  FIG. 142(A) , the contact microphone  8623  is situated touching the mastoid, which is situated in proximity to the rear from the holding part  8482   a  for the piezoelectric bimorph element. In so doing, an output unit for sound signals by cartilage conduction, and a sound input unit relying on the contact microphone  8623 , are accommodated compactly in integrated fashion within a space rearward from the auricle. In so doing, the headset  8681  will not get in the way when, for example, a helmet is worn from above. 
       FIG. 142(B) , like  FIG. 140(B) , is a system configuration diagram showing the details of the headset  8681 , together with the mobile telephone  1401 . As will be clear from  FIG. 142(B) , in the ninety-second embodiment, as in the ninetieth embodiment, the cell  8485  is situated intervening between the ear-hook unit  8482  and the contact microphone  8623 . Consequently, vibration of the anterior part  8484  is suppressed midway due to the weight of the cell  8485 , so the vibration component of the piezoelectric bimorph element  8425  that is ultimately transmitted to the contact microphone  8624  is small. 
     However, because the contact microphone  8624  directly senses vibration, despite the aforedescribed countermeasures, there is a possibility of it picking up vibration of the anterior part  8484 , transmitted from the piezoelectric bimorph element  8425 . To deal with this, as shown in  FIG. 142(B) , the signal from an acoustic processing circuit  8438  is subjected to waveform inversion by an inversion circuit  8640 , and applied to a canceller  8636 . A sound signals picked up by the contact microphone  8623  is propagated to the sound unit  8436  via the canceller  8636 , and the signal from the inversion circuit  8640  is applied to the canceller  8636  in aforedescribed manner, synthesizing the signals whereby the vibration component originating in the piezoelectric bimorph element  8425  picked up by the contact microphone  8623  is canceled, so that only sound signals generated by the vocal chords are propagated to the sound unit  8436 . 
       FIG. 143  is side views of the ear  28 , showing a modification example of the aforedescribed ninety-second embodiment. In the modification example, the position of the contact microphone is modified. Consequently, in  FIG. 143 , in order to describe this, the configuration of the head in proximity to the ear  28  is illustrated in detail, while in order to avoid complexity, illustration of the headset  8681 , except for the contact microphone, is omitted.  FIG. 143(A)  uses the aforedescribed method of illustration to show, for reference purposes, the ninety-second embodiment of  FIG. 142(A)  in which the contact microphone  8683  is situated contacting an area in proximity to a mastoid  8623   a.    
     In contrast to this,  FIG. 143(B)  is a first modification example of the ninety-second embodiment, in which a contact microphone  8723  is situated contacting an area in proximity to a lower jawbone  8623   b . Because the lower jawbone  8623   b  is close to the vocal chords, it vibrates during speech, making this a suitable location for the contact microphone  8723  to be situated. However, as the jawbone moves somewhat according to changes in the words uttered, the headset  8681  is supported flexibly in order for the contact microphone  8723  to conform to these movements. 
       FIG. 143(C)  is a second modification example of the ninety-second embodiment, in which a contact microphone  8823  is situated contacting an area in proximity the mastoid  8623   c  side of a sternomastoid muscle. Vibration of the vocal cords is propagated well through the sternomastoid muscle, and the mastoid  8623   a  side thereof vibrates during speech as well. Consequently, this region is also a suitable one for the contact microphone  8883  to be situated. However, as the mastoid  8623   a  side of a sternomastoid muscle also moves somewhat according to changes in the words uttered, the headset  8681  is supported flexibly in order for the contact microphone  8823  to conform to these movements. 
     Ninety-Third Embodiment 
       FIG. 144  is a back view and a block diagram of a ninety-third embodiment of an aspect of the present invention. The ninety-third embodiment is configured as a headset  8981  serving as an outgoing-talk/incoming-talk unit for a mobile telephone, and is of headphone type designed such that stereo listening is possible. The ninety-third embodiment has much in common with the ninety-second embodiment of  FIG. 142 , and therefore corresponding portions have been assigned the same reference numerals, omitting descriptions thereof. In the ninety-third embodiment, as in the ninety-second embodiment, cartilage conduction units are situated at locations touching an anterior part of the outside of the cartilage of the base of the ear, and a contact microphone is employed to pick up sound. 
       FIG. 144(A)  is a view of the headset  8981  of the ninety-third embodiment worn on the head, seen from the back; in order to avoid complexity, the right ear  28  and the left ear  30  are illustrated by hypothetical lines by way of the head. In the headset  8981 , a right ear unit  8924  having a right-side piezoelectric bimorph element  8924   a  and the like, and a left ear unit  8926  having a left-side piezoelectric bimorph element  8926   a  and the like, are supported on a head arm unit  8981   a . In the ninety-third embodiment, constituent elements are apportioned between the right ear unit  8924  and the left ear unit  8926 , affording a compact configuration overall which makes it possible, for example, for a helmet to be worn from above. 
     To describe in more specific terms, as shown in  FIG. 144(A) , control circuitry, such as a short-range communication unit  8487  and the like, is situated in the left ear unit  8926 , and the left-side piezoelectric bimorph element  8926   a  is supported there as well. The left-side piezoelectric bimorph element  8926   a  supported in this fashion propagates cartilage conduction from the mastoid side of the region of attachment of the auricle. Further, a contact microphone  8923 , supported by a flexible structure via an intervening left-side cell  8985   a , contacts the lower jawbone. Meanwhile, power source circuitry, such as a power supply unit  8985  and the like, is arranged in the right ear unit  8924 , and the right-side piezoelectric bimorph element  8924   a  is supported there as well. The right-side piezoelectric bimorph element  8924   a , like the left-side piezoelectric bimorph element  8926   a , propagates cartilage conduction from the mastoid side of the region of attachment of the auricle. Stereo listening is possible thereby. Further, a right-side cell  8985   b  is supported on the right ear unit  8924 . In this way, the cells, which take up space, are apportioned to the right ear unit  8924  and the left ear unit  8926 . 
       FIG. 144(B)  is a block diagram showing details of the ninety-third embodiment; portions in common with the ninety-second embodiment of  FIG. 142(B)  are assigned the same symbols, omitting descriptions. As will be clear from  FIG. 144(B) , in the ninety-third embodiment, the left-side piezoelectric bimorph element  8926   a  and the contact microphone  8923  are close together within the left ear unit  8926 , and therefore in the same manner as in the ninety-second embodiment, an inversion circuit  8640  and a canceller  8636  are furnished for canceling of vibration components originating in the piezoelectric bimorph element  8926   a  and picked up by the contact microphone  8923 . In the right ear unit  8924  on the other hand, the right-side power supply unit  8985  receives supply of power from the right-side cell  8985   b , as well as receiving supply of power from the left-side cell  8985   a  via a connecting cable inside the head arm unit  8981   a . Carrying out any necessary voltage boosting or the like on the basis of the voltage and charge capacity of the right-side cell  8985   b  and the left-side cell  8985   a , power is fed to an amplifier  8940   b  of the right ear unit  8924 , while also supplying power to the constituent components of the left ear unit  8926  through the connecting cable inside the head arm unit  8981   a . Further, an acoustic processing circuit  8438  of the left ear unit  8926  transmits left ear sound signals to an amplifier  8940   a  of the left ear unit  8926 , and transmits right ear sound signals to the amp  8940   b  of the right ear unit  8924  via the connecting cable inside the head arm unit  8981   a . In the ninety-third embodiment, vibration of the right-side piezoelectric bimorph element  8924   a  is propagated through the head arm unit  8981   a , so the component picked up by the contact microphone  8923  is sufficiently small. 
     Ninety-Fourth Embodiment 
       FIG. 145  is a back cross sectional view and a block diagram of a ninety-fourth embodiment of an aspect of the present invention. The ninety-fourth embodiment is likewise configured as a headset  9081  serving as an outgoing-talk/incoming-talk unit for a mobile telephone, and is of headphone type designed such that stereo listening is possible. The ninety-fourth embodiment has much in common with the ninety-second embodiment of  FIG. 143 , and therefore corresponding portions have been assigned the same reference numerals, omitting descriptions thereof. In the ninety-fourth embodiment, as in the ninety-second embodiment and ninety-third embodiment, cartilage conduction units are situated at locations touching an anterior part of the outside of the cartilage of the base of the ear, and a contact microphone is employed to pick up sound. 
     A point of difference between the ninety-fourth embodiment and the ninety-third embodiment is that the headset  9081  is a stereo headset of neckband type, and in association therewith, is furnished with contact microphones  9023   a  and  9023   b  and with a neckband unit  9081   a , the pair of contact microphones  9023   a  and  9023   b  being designed to pick up, from both sides, vibration of the sternomastoid muscle from the back surface of the neck. This region is close to the vocal chords and vibrates well, and as such is suited to being furnished with the contact microphones  9023   a  and  9023   b . Moreover, as discussed below, these do not pose an obstacle when wearing a helmet or the like. 
     The following specific description is based on  FIG. 145(A) .  FIG. 145(A)  is a view of the headset  9081  of the ninety-fourth embodiment worn on the head, seen from the back; as in  FIG. 144(A) , in order to avoid complexity, the right ear  28  and the left ear  30  are illustrated by hypothetical lines by way of the head. In the ninety-fourth embodiment of  FIG. 145(A) , a right ear unit  9024  having a right-side piezoelectric bimorph element  8924   a  and the like, and a left ear unit  9026  having a left-side piezoelectric bimorph element  8926   a  and the like, are supported from below by the neckband unit  9081   a . The neckband unit  9081   a  is shaped to conform to the back of the neck, the pair of contact microphones  9023   a  and  9023   b  being furnished to the inside thereof so as to lie to either side of the back surface of the neck. In so doing, vibration of the sternomastoid muscle at the back surface of the neck can be picked up in satisfactory fashion. Contact of the pair of contact microphones  9023   a  and  9023   b  against the back surface of the neck is stabilized, and vibration of the sternomastoid muscle due to vocalization from the vocal chords can be picked up in complementary fashion from both sides. 
     Like the ninety-second embodiment and the ninety third embodiment, the ninety-fourth embodiment is suited to use while wearing a helmet. In order to describe the effects of use, a cross section of a helmet  9081   b  is illustrated in  FIG. 145(A) . As is clear from  FIG. 145(A) , the inner surface of the helmet  9081   b  is of a shape loosely covering the right ear  28  and the left ear  30 , and therefore the energy of air-conducted sound generated inside the external auditory meatus of both ears  28  and  30  on the basis of cartilage conduction from the right-side piezoelectric bimorph element  8924   a  and the left-side piezoelectric bimorph element  8926   a  is prevented from dissipating to the outside from the external auditory meatus entrance, making it possible to hear sounds produced by cartilage conduction at higher volume. Moreover, because sound is not produced outside the external auditory meatus entrance due to vibration of the helmet  9081   b  or the like, external sounds audible through the helmet  9081   b  are not masked within the helmet  9081   b.    
       FIG. 145(B)  is a block diagram showing details of the configuration of the ninety-fourth embodiment, with portions in common with the ninety-third embodiment of  FIG. 144  (B) being assigned the same reference numerals, omitting descriptions thereof. As will be clear from  FIG. 145(B) , in the ninety-fourth embodiment, components of vibration of the right-side piezoelectric bimorph element  8924   a  and the left-side piezoelectric bimorph element  8926   a  propagated through the neckband unit  9081   a  and picked by the left-side contact microphone  9023   a  and the right-side contact microphone  9023   b  are sufficiently small. Consequently, the configuration involving the inversion circuit  8640  and the canceller  8683  furnished in the ninety-third embodiment for the purpose of canceling these vibration components has been omitted. 
     Ninety-Fifth Embodiment 
       FIG. 146  is a block diagram of a ninety-fifth embodiment of an aspect of the present invention. The ninety-fifth embodiment is likewise configured as a headset  9181  serving as an outgoing-talk/incoming-talk unit for a mobile telephone, and is of headphone type designed such that stereo listening is possible. The ninety-fifth embodiment has much in common with the ninety-fourth embodiment of  FIG. 145 , and therefore corresponding portions have been assigned the same reference numerals, omitting descriptions thereof. In the ninety-fifth embodiment, as in the ninety-second to ninety-fourth embodiments, cartilage conduction units are situated at locations touching an anterior part of the outside of the cartilage of the base of the ear, and a contact microphone is employed to pick up sound. 
     A difference between the ninety-fifth embodiment and the ninety-fourth embodiment is that, in order to cancel components of vibration of the right-side piezoelectric bimorph element  8924   a  and the left-side piezoelectric bimorph element  8926   a  propagated through a neckband unit  9181   a  and picked by a contact microphone  9123 , the inversion circuit  8640  and the canceller  8636  are furnished as in the ninety-third embodiment of  FIG. 144 . Further, in the ninety-fifth embodiment, unlike the ninety-fourth embodiment, the contact microphone  9123  is furnished in left-right asymmetric fashion to the neckband unit  9181   a . In specific terms, the contact microphone  9123  is furnished to a location closer to the left-side piezoelectric bimorph element  8926   a  than to the right-side piezoelectric bimorph element  8926   a.    
     As will be clear from  FIG. 146 , to counter vibration picked up from the left-side piezoelectric bimorph element  8926   a , the inversion circuit  8640  and the canceller  8636  are furnished in the same manner as in the ninety-third embodiment, and vibration components originating in the left-side piezoelectric bimorph element  8926   a  and picked up by the contact microphone  9123  are canceled. Further, in the ninety-fifth embodiment of  FIG. 146 , by furnishing an inversion circuit  9140  to counter vibration picked up from the right-side piezoelectric bimorph element  8924   a , and applying this inverted signal to the canceller  8636 , vibration components originating in the right-side piezoelectric bimorph element  8924   a  and picked up by the contact microphone  9123  are canceled. This configuration is useful for stereo listening in cases in which different sound signals are input to the right-side piezoelectric bimorph element  8924   a  and the left-side piezoelectric bimorph element  8926   a.    
     Further, in the ninety-fifth embodiment, in consideration of the fact that the right-side piezoelectric bimorph element  8924   a  is further away from the contact microphone  9123  than is the left-side piezoelectric bimorph element  8926   a , the inverted output from the inversion circuit  9140  is attenuated by an attenuation circuit  9140   a  before application to the canceller  8636 . In so doing, canceling does not become excessive at times that the picked up vibration is small. 
     The various features of the embodiments described above are not limited to the aforedescribed embodiments, and may be implemented in other aspects as well, provided that the advantages thereof can be enjoyed by doing so. For example, the features relating to concomitant use of a helmet, shown in the ninety-second to ninety fifth embodiments, can be utilized in cases not limited to ones of use in combination with a mobile telephone. For example, exchange of audio signals with outside equipment from a sound unit is not limited to short-range wireless communications, and comparable advantages can be achieved in cases of exchange through a wired connection as well. 
     Summary 
     The following is a description summarizing the various technical features that have been disclosed in the present specification. 
     First Technical Feature 
     A first technical feature disclosed in the present specification provides a mobile telephone in which the upper part of the mobile telephone is provided with a cartilage conduction vibration unit that makes contact with ear cartilage. It is thereby possible to provide a mobile telephone which makes use of the excellent performance exhibited by ear cartilage in regard to transmitting audio information, and which can be used without a sense of discomfort from pressure or insertion into the ear, the user experience being similar to that of the normal state of a telephone call. 
     According to a specific feature, the cartilage conduction vibration unit is configured so as not to protrude from the outer wall of the mobile telephone. It is thereby possible to achieve a shape whose absence of awkward protruding parts caused by the arrangement of the cartilage conduction vibration unit compromises neither the function nor the aesthetics of the mobile telephone. 
     According to a more specific feature, the cartilage conduction vibration unit is arranged at an upper part corner on the ear side of the mobile telephone. It is thereby possible to achieve an arrangement where the cartilage conduction vibration unit does not protrude from the outer wall of the mobile telephone, by which natural contact with the ear cartilage can be realized. 
     According to an even more specific feature, the cartilage conduction vibration unit is arranged on one of the upper part corners on the ear side of the mobile telephone that faces diagonally downward in the usage posture. It is thereby possible for the cartilage conduction vibration unit to be brought into contact with the ear cartilage in a state that is awkward neither to the person making the telephone call nor to onlookers, due to the posture approximating the normal state of a telephone call, in which the mobile telephone is held by hand and brought up against the ear. Such a posture is doubly suitable, due to being suitable for making contact with the tragus and due to the tragus being particularly highly effective in terms of cartilage conduction. 
     According to another specific feature, there are two of the cartilage conduction vibration units provided to the upper part of the mobile telephone. Such a configuration is suitable by virtue of there being more effective contact with the ear cartilage. The two cartilage conduction vibration units can, for example, be configured such that one is made to vibrate in accordance with whether the right ear or the left ear is being used, thus providing support for switching between holding with the left and right hand. 
     According to a further specific feature, a sensor for detecting which of the two cartilage conduction vibration units is in contact with the ear is provided to the upper part of the mobile telephone, and one of the two cartilage conduction vibration units is made to vibrate in accordance with the output of the sensor. Alternatively, a gravitational acceleration detection unit is instead provided, one of the two cartilage conduction vibration units being made to vibrate in accordance with the direction of gravitational acceleration detected by the gravitational acceleration detection unit. The elements described above may also be used concurrently to detect when the hand holding the mobile telephone is switched. 
     According to another feature, in a mobile telephone having a videoconferencing function, the functions of the cartilage conduction vibration unit are prohibited whenever the videoconferencing function is in operation. The cartilage conduction vibration unit can thereby be prevented from functioning without purpose in the state where the mobile telephone is not to be brought up against the ear. 
     According to yet another feature, a folding structure is included, the functions of the cartilage conduction vibration unit being prohibited in a folded state in a case where the cartilage conduction vibration unit is arranged at a position at which contact with the ear cartilage becomes impossible in the folded state. The cartilage conduction vibration unit can thereby be prevented from functioning without purpose in the state where the mobile telephone cannot be held up against the ear. 
     According to another feature, there is provided an audio output device, comprising: an audio output unit; a controller for simultaneously outputting audio information to the audio output unit and the cartilage conduction vibration unit; and a phase adjustment unit for phase-adjusting the phase of an audio signal being outputted to the audio output unit and the cartilage conduction vibration unit. It is thereby possible to prevent the adverse event caused when the same audio information is transmitted by two systems, i.e., bone conduction and air vibration from the external auditory meatus. 
     According to another feature, there is provided an audio output device, comprising: a bone conduction vibration unit, an environment noise microphone; and a phase adjustment unit for inverting the phase of, and then outputting to the cartilage conduction vibration unit, audio information that has been picked up by the environment noise microphone. It thereby becomes possible to cancel out the environment noise from the environment noise and useful audio information conducted by air vibration from the external auditory meatus. 
     Second Technical Feature 
     A second technical feature disclosed in the present specification provides a mobile telephone having cartilage conduction vibration unit, which includes a cartilage conduction vibration source, as well as a cartilage conductor for guiding the vibration of the cartilage conduction vibration source to the upper part of the mobile telephone in contact with the ear cartilage. It is thereby possible to provide a mobile telephone that makes use of the excellent performance exhibited by ear cartilage in regard to transmitting audio information, and which can be used without a sense of discomfort from pressure or insertion into the ear, the user experience approximating that of the normal state of a telephone call. Furthermore, according to the configuration of the cartilage conduction vibration unit described above, the vibration of the cartilage conduction vibration source is guided by the cartilage conductor to a desired position, which is advantageous in that a greater amount of freedom is provided for the layout of the cartilage conduction vibration source itself and in that the cartilage conduction vibration unit can be installed on a mobile telephone lacking any available extra space. 
     According to a specific feature, the cartilage conduction vibration source and the cartilage conductor are configured so as not to protrude from an outer wall of the mobile telephone. It is thereby possible to achieve a shape whose absence of awkward protruding parts caused by the arrangement of the cartilage conduction vibration unit compromises neither the function nor the aesthetics of the mobile telephone. According to an even more specific feature, the end part of the cartilage conductor is arranged at an upper part corner of the ear side of the mobile telephone. It is thereby possible to achieve an arrangement where the cartilage conduction vibration units do not protrude from the outer wall of the mobile telephone, by which a natural contact with the ear cartilage can be realized. According to a further specific feature, the end part of the cartilage conductor is arranged on one of the upper part corners on the ear side of the mobile telephone that faces diagonally downward during the usage posture. It is thereby possible for the cartilage conduction vibration unit to be brought into contact with the ear cartilage in a state that is awkward neither to the person making the telephone call nor to onlookers, due to the posture approximating the normal state of a telephone call, in which the mobile telephone is held by hand and brought up against the ear. Such a posture is doubly suitable, because it is suitable for contact with the tragus and also because the tragus is particularly highly effective in terms of cartilage conduction. 
     According to another specific feature, the two ends of the end parts of the cartilage conductor are arranged at both corners of the upper part on the ear side of the mobile telephone. Such a configuration is suitable by virtue of there being more effective contact with the ear cartilage. One of the two ends of the end parts of the cartilage conductor can, for example, be brought into contact with the ear cartilage as appropriate, in accordance with whether the right ear or the left ear is being used, thus providing support for readily switching between holding the mobile telephone with the left and right hand. 
     According to another feature, there is provided a mobile telephone comprising: a cartilage conduction vibration unit brought into contact with ear cartilage; a gravitational acceleration detection unit; and a controller for prohibiting the cartilage conduction vibration unit from vibrating whenever the gravitational acceleration detection unit detects that the mobile telephone is in a stationary state. It is thereby possible to prevent the cartilage conduction vibration unit from uselessly vibrating and generating a distracting sound when, for example, the mobile telephone is placed on a desk or the like with the cartilage conduction vibration unit facing down. 
     According to a specific feature, the mobile telephone includes a sensor for detecting the presence or absence of an object in proximity with the cartilage conduction vibration unit, where the controller causes the cartilage conduction vibration unit to vibrate in accordance with whether the sensor detects an object in proximity, and prohibits the cartilage conduction vibration unit from vibration, irrespective of whether the sensor detects an object in proximity, whenever the gravitational acceleration detection unit detects that the mobile telephone is in a stationary state. The sensor for detecting the presence or absence of an object in proximity is a useful configuration for detecting when the mobile telephone has been brought up against the ear and causing the cartilage conduction vibration unit to vibrate, but when, for example, the mobile telephone has been placed on a desk or the like, there is the potential for this state to be falsely confirmed as contact to the ear and for the cartilage conduction vibration unit to be made to vibrate. Herein, the aforesaid specific feature can prevent the generation of uncomfortable sound due to the vibration of the cartilage conduction vibration unit based on such false confirmation. 
     According to another feature, there is provided a mobile telephone comprising: a cartilage conduction vibration unit to be brought into contact with ear cartilage; an audio input unit; a phase inverter for phase-inverting audio information inputted from the audio input unit; and a controller for outputting, from the cartilage conduction vibration unit, the audio information having been phase-inverted by the phase inverter. It is thereby possible to appropriately minimize any discomfort based on one&#39;s own voice during a conversation by mobile telephone in the state where the cartilage conduction vibration unit has been brought into contact with the ear cartilage. 
     According to a specific feature, the mobile telephone includes an acoustics adjustment unit, where the controller outputs, from the cartilage conduction vibration unit, audio information that has been acoustically adjusted by the acoustics adjustment unit and also phase-inverted by the phase inverter. It is thereby possible to more appropriately minimize any discomfort that is based on one&#39;s own voice during a conversation by mobile telephone. 
     According to another specific feature, the mobile telephone includes a contact state detection unit for detecting the state where the cartilage conduction vibration unit is in contact with the ear cartilage, where the controller determines whether or not to output, from the cartilage conduction vibration unit, audio information that has been phase-inverted by the phase inverter in accordance with the state detected by the contact state detection unit. It is thereby possible to more appropriately control the discomfort that is based on one&#39;s own voice in accordance with the state where the mobile telephone is in contact with the ear cartilage. 
     According to a more specific feature, the contact state detection unit detects when the cartilage conduction vibration unit is in contact with the ear cartilage in the state where the ear hole is blocked by the mobile telephone being in contact with the ear cartilage, the earplug bone conduction effect thus occurring, where the controller outputs, from the cartilage conduction vibration unit, audio information that has been phase-inverted by the phase inverter in accordance with a detection that the cartilage conduction vibration unit is in contact with the ear cartilage in the state where the earplug bone conduction effect occurs. The earplug bone conduction effect, which occurs due to the ear hole being blocked, achieves a listening status with dual effects, in which audio information from the cartilage conduction vibration unit is conducted by even louder sound and in which environmental noise is obstructed. However, the earplug bone conduction effect is meanwhile accompanied by the discomfort of one&#39;s own voice through bone conduction from the vocal cords. The aforesaid feature is advantageous in attenuating such discomfort of one&#39;s own voice. 
     According to another feature, there is provided a piezoelectric element control device comprising: a conduction vibration unit that includes a piezoelectric element and transmits vibration of the piezoelectric element by being brought into contact with a body to which conduction is directed; a signal output unit for outputting conduction vibration information to the piezoelectric element; and a pressure detection unit for detecting, through the piezoelectric element, changes in the contact pressure between the conduction vibration unit and the body to which conduction is directed. By such a configuration, the piezoelectric element can serve a dual purpose as an output element for contact vibration and also as a contact pressure sensor, and conduction vibration can be outputted in accordance with a variety of circumstances. Such a piezoelectric element control device is configured as a mobile telephone, the body to which conduction is directed being the ear cartilage, and is suitable for detecting the state where the cartilage conduction vibration unit is in contact with the ear cartilage depending on the pressure changes sensed by the piezoelectric element. 
     Third Technical Feature 
     A third technical feature disclosed in the present specification provides a mobile telephone comprising a cartilage conduction vibration source and a conductor for guiding the vibration of the cartilage conduction vibration source to the ear cartilage, wherein the conductor is an elastic body. It is thereby possible to effectively listen to the audio information from the cartilage conduction vibration source, and possible to achieve softer contact with the ear. 
     According to a specific feature, the conductor is sized so as to contact the ear cartilage at a plurality of points. Effective cartilage conduction can thereby be obtained. 
     According to another specific feature, the conductor is sized so as to contact the ear cartilage and block the external auditory meatus. It is thereby possible to effectively listen to audio information from the cartilage conduction vibration source, and effectively reduce exterior noise. 
     According to another specific feature, the conductor has at least a surface area approximating that of the ear lobe. It is thereby possible to effectively listen to audio information from the cartilage conduction vibration source, and block the external auditory meatus in a natural manner according to need. 
     According to another specific feature, the conductor has an acoustic impedance approximating the acoustic impedance of ear cartilage. Audio information from the cartilage conduction vibration source can accordingly be effectively guided to the ear cartilage. 
     According to another specific feature, the conductor is configured as a cover for the mobile telephone. According to such a configuration, housing the mobile telephone in the cover makes it possible to effectively listen to audio information from the cartilage conduction vibration source in a natural manner. 
     According to a more specific feature, the mobile telephone includes an outgoing-talk unit (microphone), and the cover of the mobile telephone includes Larsen effect prevention means between the conduction vibration source and the outgoing-talk unit. It is thereby possible to prevent the Larsen effect while also possible to effectively listen to the audio information from the cartilage conduction vibration source. According to another more specific feature, the mobile telephone includes an outgoing-talk unit, and the cover of the mobile telephone includes an air conduction unit in the vicinity of the outgoing-talk unit. It is thereby possible to listen to the voice of the other party, which is generated by the bone conduction vibration source, while also sending one&#39;s own voice from the outgoing-talk unit, and also thereby possible to have a two-way conversation in a natural manner, even while the mobile telephone remains housed in the cover. 
     According to another specific feature, the conductor is configured as a grip unit of the mobile telephone. It is thereby possible to introduce, to the mobile telephone, an elastic body for effectively guiding the audio information of the conductor, in a manner that is in harmony with the other functions of the mobile telephone. 
     According to another feature, there is provided a mobile telephone comprising: a cartilage conduction vibration source serving as an incoming-talk unit; a conduction vibration source serving as an incoming-talk unit; and a shared outgoing-talk unit. It is thereby possible to provide a mobile telephone permitting a two-way conversation in accordance with the environment of the telephone call. Specifically, providing the shared outgoing-talk unit to an end part of the mobile telephone is useful for the aforesaid configuration. 
     According to another feature, there is provided a mobile telephone comprising: a cartilage conduction vibration source; and a conductor for guiding vibration of the cartilage conduction vibration source to the ear cartilage; wherein the conductor is sized so as to contact the ear cartilage at a plurality of points; is sized so as to contact the ear cartilage and block the external auditory meatus; has at least a surface area approximating that of an ear lobe; or has an acoustic impedance approximating the acoustic impedance of the ear cartilage. Any of these features or a combination thereof makes it possible to listen effectively to sound information using the cartilage conduction vibration source. 
     Fourth Technical Feature 
     A fourth technical feature disclosed in the present specification provides a mobile telephone comprising: a cartilage conduction vibration source; a mobile telephone body; an anti-impact cushioning part provided between the mobile telephone body and the cartilage conduction vibration source; and a conductor for guiding the vibration of the cartilage conduction vibration source to the ear cartilage. A vibration source resistant to impact can thereby be employed in a mobile telephone as the cartilage conduction vibration source. According to a specific feature, the conductor is an elastic body. It is thereby possible to cushion impact on the mobile telephone body and additionally impact from outside the conductor, and also thereby possible to obtain effective cartilage conduction. According to another specific feature, a vibration source resistant to impact and suitable as a cartilage conduction vibration source includes a piezoelectric bimorph element. 
     According to another specific feature, the anti-impact cushioning part and the conductor are configured so as to enclose the cartilage conduction vibration source. It is thereby possible to effectively cushion the cartilage conduction vibration source while also rendering the cartilage conduction more effective, rather than compromising the efficacy of cartilage conduction. According to yet another specific feature, the conductor and the anti-impact cushioning part are composed of the same material. According to a further specific feature, the cartilage conduction vibration source is inserted into and integrally molded with the conductor and anti-impact cushioning part. It is thereby made possible to provide a practical configuration by which cushioning efficacy and favorable cartilage conduction efficacy can be simultaneously achieved. According to another specific feature, the conductor and anti-impact cushioning part are joined sandwiching the cartilage conduction vibration source. It is thereby made possible to provide another practical configuration by which cushioning efficacy and favorable cartilage conduction efficacy can be simultaneously achieved. 
     According to yet another feature, the conductor is sized so as to contact the ear cartilage at a plurality of points. According to another specific feature, the conductor is sized so as to contact the ear cartilage and block the external auditory meatus. According to yet another specific feature, the conductor has at least a surface area approximating that of the ear lobe. According to another specific feature, the conductor has an acoustic impedance approximating the acoustic impedance of the ear cartilage. These features make it possible to render cartilage conduction more effective and to reduce exterior noise in accordance with need, while simultaneously cushioning the cartilage conduction vibration source. 
     According to another feature, there is provided a mobile telephone comprising: a cartilage conduction vibration source; a conductor for guiding the vibration of the cartilage conduction vibration source to the ear cartilage; and a resonator for converting the vibration of the cartilage conduction vibration source to air conduction. It is thereby made possible to create a dual use for the cartilage conduction vibration source and to simultaneously obtain both favorable cartilage conduction from the conductor and air conduction from the resonator; it is also thereby possible to effectively listen to sound information. 
     According to a specific feature, the conductor is a rigid body. Cartilage conduction conducts differently depending on the amount of force pushing on the cartilage, and a state of effective conduction can be obtained by increasing the amount of force that is pushing, but this means that when it is difficult to hear the incoming sound, a natural behavior such as increasing the force pushing the mobile telephone against the ear can be utilized to adjust the volume. Such a function also makes it possible to more effectively adjust the volume through adjusting the force that is pushing, due to the conductor being constituted of a rigid body. 
     According to another specific feature, the resonator is an elastic body. The resonator thereby creates cartilage conduction through contact with the tragus or other part of the ear cartilage, and sound from the outer surface of the resonator, which resonates according to the vibration of the cartilage conduction vibration source, is conducted to the tympanic membrane from the external auditory meatus as sound waves. It is thereby possible to effectively listen to sound. 
     According to another specific feature, the resonator is sized so as to contact the ear cartilage at a plurality of points. According to another specific feature, the resonator is sized so as to contact the ear cartilage and block the external auditory meatus. According to yet another specific feature, the resonator has an acoustic impedance approximating the acoustic impedance of the ear cartilage. These features make it possible to render cartilage conduction more effective and to reduce exterior noise in accordance with need. 
     According to another specific feature, the resonator constitutes the incoming-talk unit of the mobile telephone by air conduction. It is thereby made possible to create a dual use for the cartilage conduction vibration source and constitute a typical incoming-talk unit, and also possible to listen to sound in a natural posture, on the basis of the vibration of the cartilage conduction vibration source, without the incoming-talk unit being provided separately. 
     According to another feature, there is provided a mobile telephone comprising: a cartilage conductor for conducting vibration for cartilage conduction to ear cartilage; a resonator for generating sound waves to be conducted to the tympanic membrane through the external auditory meatus by air conduction; and a shared vibration source having a dual purpose as a vibration source for the cartilage conductor and the resonator. It is thereby made possible to create a dual use for the shared vibration source and constitute a cartilage conduction output unit and a typical incoming-talk unit, and also possible to listen to sound in a natural posture, on the basis of the vibration of the shared vibration source, without the incoming-talk unit being provided separately. 
     According to a specific feature, a suitable example of the vibration source includes a piezoelectric bimorph element. It is thereby possible to provide a vibration source suitable for generating favorable cartilage conduction and suitable for a typical incoming-talk unit for generating sound to be conducted to the tympanic membrane from the external auditory meatus. 
     Fifth Technical Feature 
     A fifth technical feature disclosed in the present invention provides a mobile telephone comprising: a display surface; a side surface relative to the display surface; and a cartilage conduction vibration unit provided to the side surface and capable of coming into contact of the ear cartilage. The display surface can thereby be prevented from making contact with the ear, cheek, or other body part and from becoming fouled when the cartilage conduction vibration unit is brought into contact with the ear cartilage. 
     According to a specific feature, cartilage conduction vibration units are provided to each of both side surfaces of the display surface. The cartilage conduction vibration unit can thereby be brought into contact with the right ear or the left ear from the state where the display screen is being viewed, without the need to switch the hand holding the mobile telephone. According to a further specific feature, there is provided an incoming-talk unit which is used consistently in any case where either of the cartilage conduction vibration units is being used. 
     According to another specific feature, the incoming-talk unit is provided nearer to the side surface to which the cartilage conduction vibration unit is provided. In such a case, merely providing the cartilage conduction vibration unit to the side surface on a single side allows for the cartilage conduction vibration unit to be brought into contact with the right ear or the left ear by the mobile telephone being turned over. According to a further specific feature, the cartilage conduction vibration unit and the incoming-talk unit form an incoming/outgoing talk unit, which can be inserted into and removed from the mobile telephone. The ability to insert or remove such an incoming/outgoing talk unit allows for flexible usage. According to a further specific feature, the incoming/outgoing-talk unit is configured so as to be capable of short-range wireless communication or so as to be capable of wired communication with the mobile telephone. 
     According to another specific feature, an auxiliary holding unit is provided to the side surface of the side opposite the side surface to which the cartilage conduction vibration unit is provided. The mobile telephone can thereby be more readily held when the cartilage conduction vibration unit is brought into contact with the ear cartilage, and the display surface can thereby be prevented from becoming fouled by fingerprints or the like due to being held during a telephone call. According to a more specific feature, the auxiliary holding unit is configured so as to be extensible from the side surface, in order to prevent the compactness of the mobile telephone from being compromised when the auxiliary holding unit is not needed. 
     According to another feature, there is provided a mobile telephone comprising: a display surface; a cartilage conduction vibration unit which can be brought into contact with the ear cartilage; a detection unit for detecting when the cartilage conduction vibration unit has been contacted with the ear cartilage; and a display controller for changing the display of the display unit to a privacy protection display on the basis of the detection by the detection unit. 
     The feature above makes it possible to prevent another person from catching a glance of a display relating to the call destination or other form of private information during a telephone call. Such a configuration is suitable for when the state becomes such that the display surface is no longer hidden by the posture of the mobile telephone when the cartilage conduction vibration unit is brought into contact with the ear cartilage. An example of a privacy protection display is a predetermined display not containing any private information or a state where nothing is displayed. According to a more specific feature, the display unit is turned on during the privacy protection display, and the display unit is turned off in order to conserve power whenever the detection by the detection unit continues for a predetermined period of time or longer. 
     According to another feature, there is provided a mobile telephone system which includes: a mobile telephone body; and an incoming/outgoing-talk unit, which can be inserted into or removed from the mobile telephone body, and which includes an incoming-talk unit and a cartilage conduction vibration unit that can be brought into contact with the ear cartilage. 
     The feature above makes it possible to enable cartilage conduction in the state where the incoming/outgoing-talk unit is incorporated into the mobile telephone body as well as cartilage conduction in the state where the incoming/outing-talk unit is separated therefrom, and also makes it possible to provide a system permitting flexible usage in accordance with the circumstances. According to a specific feature, the incoming/outgoing-talking unit is configured so as to be capable of short-range wireless communication or so as to be capable of wired communication with the mobile telephone body. 
     According to another feature, there is provided an incoming/outgoing-talk unit for a mobile telephone including a cartilage conduction vibration unit which can be brought into contact with the ear cartilage, an incoming-talk unit, and a unit for communicating with the mobile telephone. Such an incoming/outgoing-talk unit is not only suitable for constituting a mobile telephone system by being combined with a specific mobile telephone, but also assumes a configuration suitable for serving as an incoming/outgoing-talk accessory for a general mobile telephone having a communication unit. According to a specific feature, the incoming/outgoing-talk unit is configured in a pencil shape in which the cartilage conduction vibration unit and the incoming-talking unit are arranged in the vicinity of both ends. According to another specific feature, the communication unit is configured as a short-range wireless communication unit. According to yet another feature, the communication unit is configured so as to include a cable for wired communication with the mobile telephone. 
     According to another specific feature, the communication unit transmits, to the mobile telephone, information relating to the state of contact between the cartilage conduction vibration unit and the ear cartilage. It is thereby made possible for information specific to the usage of the cartilage conduction vibration unit to be transmitted to the mobile telephone, and it is also thereby possible for there to be a favorable link with the mobile telephone. 
     Sixth Technical Feature 
     A sixth technical feature disclosed in the present specification provides an incoming/outgoing talk unit for a mobile telephone comprising: an ear-attachment unit; a cartilage conduction vibration unit for making contact with the ear cartilage in the state of attachment by the attachment unit; an outgoing-talk unit; and a short-range wireless communication unit for use with the mobile telephone. This makes it possible to achieve an incoming/outgoing-talk unit suitable for a mobile telephone. An example of suitable ear cartilage in the above is the tragus, by which typically audio information can be transmitted without the ear hole being blocked. 
     According to a specific feature, the incoming/outgoing-talk unit includes a movable unit that is movable relative to the attachment unit, and the cartilage conduction vibration unit is held to the movable unit. According to a further specific feature, the movable unit can be moved in order to alter the state where the cartilage conduction vibration unit is in contact with the cartilage. 
     According to another specific feature, the short-range wireless communication unit transmits, to the mobile telephone, information relating to the position of the movable unit. The mobile telephone is thereby able to transmit appropriate audio information to the incoming/outgoing-talk unit. According to a more specific feature, the short-range wireless communication unit transmits, to the mobile telephone, information relating to the position of the movable unit relative to the attachment unit. 
     According to another feature, the cartilage conduction vibration unit is held via an elastic body. It is thereby possible to cushion an impact against the cartilage conduction vibration unit and also to allow the cartilage conduction vibration unit to move. According to a further specific feature, the cartilage conduction vibration unit is contained and held in the elastic body. This makes it possible to achieve greater cushioning for the cartilage conduction vibration unit. 
     According to a more specific feature, the aforesaid elastic body containing the cartilage conduction vibration unit has an acoustic impedance approximating the acoustic impedance of the ear cartilage. Cushioning for the cartilage conduction vibration unit and suitable cartilage conduction via the elastic body are thereby rendered possible. 
     According to another specific feature, the cartilage conduction vibration source includes a piezoelectric bimorph element. Suitable cartilage conduction vibration is thereby provided. Being held by the aforesaid elastic body is beneficial for the cushioning of such a piezoelectric bimorph element. 
     According to another specific feature, a phase inverter for phase-inverting audio information inputted from the outgoing-talk unit and a controller for outputting, from the cartilage conduction vibration unit, audio information that has been phase-inverted by the phase inverter are positioned in the incoming/outgoing-talk unit. It is thereby possible to provide a highly versatile incoming/outgoing-talk unit making use of the advantages specific to cartilage conduction. According to a further specific feature, an acoustics adjustment unit is provided to the incoming/outgoing-talk unit, and the aforesaid controller outputs, from the cartilage conduction vibration unit, audio information that has been acoustically adjusted by the acoustics adjustment unit and phase-inverted by the phase inverter. More appropriate control is thereby made possible. 
     According to a more specific feature, a contact state detection unit for detecting the state where the cartilage conduction vibration unit is in contact with the ear cartilage is provided to the incoming/outgoing-talk unit, and the controller determines whether or not to output, from the cartilage conduction unit, audio information that has been phase-inverted by the phase inverter, in accordance with the state detected by the contact state detection unit. Appropriate control is thereby made possible. 
     According to another specific feature, the attachment unit is an ear-hooking unit, and the incoming/outgoing-talk unit is configured as a headset. The various features described above are suitable for constituting such a headset. 
     According to another specific feature, the attachment unit is the temple of a pair of eyeglasses, and the incoming/outgoing-talk unit is configured as a pair of eyeglasses. The various features described above are suitable for constituting such a pair of eyeglasses. According to a more specific feature, the cartilage conduction vibration unit can be moved relative to the temple of the eyeglasses. It is thereby possible to withdraw the incoming/outgoing-talk unit whenever a two-way conversation is not being held. 
     Seventh Technical Feature 
     A seventh technical feature disclosed in the present specification provides an incoming-talk unit which includes: an ear-attachment unit; and a cartilage conduction vibration unit for conduction cartilage conduction from the outer side of the ear cartilage in the state of attachment by the attachment unit. It is thereby possible to listen to audio information without the external auditory meatus being blocked in both a natural state and a normal state. There are conventionally known eyeglasses-type and other types of bone conduction incoming-talk devices for listening to audio information without the external auditory meatus being blocked, but in the case of using bone conduction, the bone at the front or the rear of the ear must be tightly tucked in by the portion of the inner side or other part of the temple of the eyeglasses, which results in pain and renders long-term usage unbearable. An incoming-talk unit provided with the feature above will not have such a problem, it being possible to listen comfortably to audio information while experiencing a sensation similar to that of ordinary eyeglasses. According to a specific feature, the ear cartilage to which the cartilage conduction is to be conducted is the base of the ear. The outer side of the cartilage of the base of the ear, being close to the inner entrance of the external auditory meatus, is suitable for transmitting sound to the tympanic membrane by generating air conduction to the interior of the external auditory meatus from the cartilage around the entrance to the external auditory meatus, and for direct conduction to the inner ear through the cartilage. 
     According to another specific feature, the attachment unit is the temple of eyeglasses. In such a case, the vibration of the cartilage conduction vibration unit can be conducted from the outer side of the ear cartilage through the natural operation of hooking on the eyeglasses. Accordingly, there is no need to clamp down on the bones of the face with the temples of the eyeglasses, as is done in the case of bone conduction. According to a more specific feature, the cartilage conduction vibration unit can be inserted into or removed from the temple of the eyeglasses. It is thereby made possible to conduct cartilage conduction from the outer side of the ear cartilage merely by having the cartilage conduction vibration unit worn on the temple of ordinary eyeglasses, even though the eyeglasses may not be specially designed so as to be provided with the cartilage conduction vibration unit. 
     According to a further specific feature, the incoming-talk unit includes a pair of fitting parts which can each be fitted to the pair of temples of the eyeglasses, and cartilage conduction vibration units are fitted to the temples of the eyeglasses by the fitting parts being fitted. According to a more specific feature, the pair of fitting parts are connected by a glass cord, thus obtaining the practical advantages of a harmonious design and loss prevention. According to a more specific feature, the fitting parts are elastic bodies, thus achieving a degree of freedom in the fitting. 
     According to a further specific feature, one of the aforesaid pair of fitting parts is a dummy. Given that the cartilage conduction vibration unit is fitted only to one ear, a fitting part need only be fitted to one temple, but that alone will be enough to change the thickness of the temple, giving rise to the concern that the eyeglasses will tilt. Therefore, the dummy fitting part is fitted to the other temple, whereby it is possible to maintain the balance of the eyeglasses when the cartilage conduction vibration units are fitted. 
     According to another specific feature, the cartilage conduction vibration unit is arranged on one of the pair of fitting parts, and a power source is arranged at the other. It is thereby possible to arrange the cartilage conduction vibration unit and the related constituent elements in a limited space while the left and right temples are also balanced. It is further possible to connect the pair of fitting parts with a glass cord having a dual purpose for creating an electric connection between the two, whereby a plurality of constituent elements can be divided to the left and right temples while a harmonious design and also a mutual electric connection can be maintained. 
     According to another further specific feature, cartilage conduction vibration units are arranged at both of the pair of fitting parts. It is thereby possible to listen to audio information stereophonically while achieving a balance between the left and right temples. According to another feature, the cartilage conduction vibration units can also be arranged directly on both of the pair of temples of the eyeglasses. 
     According to another specific feature, the incoming-talk unit is provided with: a detection unit for detecting when the ear cartilage are deformed due to the ear being covered; an outgoing-talk unit; a phase inverter for phase-inverting audio information inputted from the outgoing-talk unit; and a controller for outputting, from the cartilage conduction vibration unit, the audio information that has been phase-inverted by the phase inverter in accordance with the detection by the detection unit. It is thereby possible to attenuate the discomfort of one&#39;s own voice when the ear is covered in order to listen to louder audio information and the earplug bone conduction effect is produced, while also obstructing exterior noise. 
     According to another specific feature, the attachment unit is an ear-hooking unit. In such a case, even a person who does not require eyeglasses can listen to audio information in a natural state and a normal state without the external auditory meatus being blocked. 
     According to another feature, there is provided an incoming-talk unit for 3D viewing, comprising: a 3D viewing adjustment unit; a temple including a unit for adjusting contact with the temple of eyeglasses for adjusting vision when fitted over eyeglasses for adjusting vision; and an audio information output unit provided to the temple. It is thereby possible to appropriately listen to audio information both in a case where the incoming-talk unit for 3D viewing is fitted directly without eyeglasses, and also in a case where the same is fitted over eyeglasses for adjusting vision. 
     According to a specific feature, the audio information output unit is a cartilage conduction vibration unit. According to a further specific feature, the cartilage conduction vibration unit conducts cartilage conduction from the outer side of the ear cartilage. The aforesaid contact adjustment unit allows for the vibration of the cartilage conduction vibration unit to be effectively transmitted from the outer side of the ear cartilage in particular when the incoming-talk unit for 3D viewing is fitted over the eyeglasses for adjusting vision. 
     Eighth Technical Feature 
     An eighth technical feature disclosed in the present specification provides a mobile telephone comprising: a cartilage conduction vibration source for guiding an audio signal to the ear cartilage; and a low-frequency source for guiding, to the cartilage conduction vibration source, a low-frequency vibration signal of a lower signal than the audio signal. The vibration source can thereby be given a dual purpose for cartilage conduction and low-frequency vibration, and the cost of the vibration source and thereby be reduced. 
     According to a specific feature, a mobile telephone is provided with a touch detection unit for detecting touch by a finger, wherein the low-frequency source introduces, to the cartilage conduction vibration source, the low-frequency vibration signal in response to a detection of touch by the touch detection unit, and transmits the low-frequency vibration of the cartilage conduction vibration source to the finger touching. A suitable example of such a touch detection unit is a touch panel provided to a display screen. 
     According to another specific feature, the cartilage conduction vibration source serves a dual purpose as the touch detection unit. The cartilage conduction vibration source can thereby serve to guide audio signals to the ear cartilage, to output low frequencies, and to detect touch, and the cost of the vibration source can also thereby be reduced. This feature is suitable for a case where a contact-free motion sensor for detecting movement in the vicinity of the display screen is provided. 
     According to another specific feature, a delay lasting a predetermined period of time after the detection by the touch detection unit is allowed to pass, and the low-frequency vibration signal is introduced to the cartilage conduction vibration source. Feedback for a touch result can thereby be provided to the finger touching, without confusion. 
     According to another specific feature, a vibration insulation material for preventing the transmission of audio signals is interposed between the cartilage conduction vibration source and an outer wall part for outwardly conduction the vibration of the cartilage conduction vibration source, which is made to vibrate by the introduction of a low-frequency vibration signal having a low frequency. The leakage of audio signals to the outer wall part and elsewhere, the generation of unneeded air conduction, and other defects can thereby be prevented. 
     According to a further specific feature, the vibration insulation material prevents the transmission of vibration having a frequency at or above a predetermined frequency, and permits the transmission of vibration at or below the predetermined frequency. An audio signal thereby enables a low-frequency vibration to be relayed to the outer wall part from the cartilage conduction vibration source even while there is obstruction. According to another further specific feature, a low-frequency signal of the low-frequency source is configured so as to include the resonance frequency of the vibration insulation material. An audio signal can thereby cause the vibration insulation material to resonate for a low-frequency vibration even while there is obstruction, whereby the low-frequency vibration can be transmitted to the outer wall part from the cartilage conduction vibration source. 
     According to another specific feature, a switching unit for switching between introducing an audio signal and introducing a low-frequency signal of a low frequency is provided to the cartilage conduction vibration source. The cartilage conduction vibration source can thereby be appropriately applied to a plurality of objectives. 
     According to another specific feature, there is provided an audio signal output device for a mobile telephone characterized by comprising: eyeglass lenses; eyeglass temples; cartilage conduction vibration units for conducting cartilage conduction from the outer side of the ear cartilage, which are arranged at the eyeglass temples; a sound signal source unit for transmitting output to the cartilage conduction vibration units; and a unit for communicating with the mobile telephone. Diverse links with the mobile telephone are thereby made possible. According to a further specific feature, incoming-talk units are provided to the eyeglass temples; as an example of a more specific feature, the incoming-talk units are configured as bone conduction microphones. Such configurations are appropriately used for eyeglass temples naturally brought up against the face when the eyeglasses are worn, and permit two-way conversation. 
     According to another feature, there is provided a sound signal output device which includes: eyeglass lenses; eyeglass temples; cartilage conduction vibration units for conducting cartilage conduction from the outer side of the ear cartilage, which are arranged at the eyeglass temples; and a sound signal source unit for transmitting output to the cartilage conduction vibration units. A person wearing the eyeglasses can thereby enjoyably receive sound signals of the sound signal source unit in a natural state. According to a specific feature thereof, the eyeglass temples are a pair, and the cartilage conduction vibration units are arranged at each of both of the pair of eyeglass temples, and the output of the sound signal source unit is transmitted to each of the cartilage conduction vibration units. A pair of temples originally provided to eyeglasses can thereby be utilized and stereo sound signals can be enjoyably received without the ear being blocked. 
     According to another feature, there is provided a sound signal output device for a mobile telephone characterized by comprising: eyeglass lenses; eyeglass temples; cartilage conduction vibration units for conducting cartilage conduction from the outer side of the ear cartilage, which are arranged at the eyeglass temples; bone conduction microphones arranged at the eyeglass temples; and a unit for communicating with the mobile telephone. It is thereby possible to provide an incoming/outgoing-talk unit suitable for a mobile telephone for a person who wears eyeglasses. 
     Ninth Technical Feature 
     A ninth technical feature disclosed in the present specification provides a mobile telephone characterized by comprising: a cartilage conduction vibration source having a primary vibration direction, the cartilage conduction vibration source being adapted to guide an audio signal to the ear cartilage; a holding structure for avoiding the primary vibration direction and for holding the cartilage conduction vibration source; and an audio signal input unit for inputting an audio signal to the cartilage conduction vibration source. An audio signal can thereby be effectively guided to the ear cartilage, and useless vibration of the cartilage conduction vibration source can be prevented from being conducted to the mobile telephone. 
     According to a specific feature, the mobile telephone is provided with a vibration output structure for guiding, to the outer surface of the mobile telephone, vibration in the primary vibration direction of the cartilage conduction vibration source. An audio signal can thereby be effectively guided to the ear cartilage from the cartilage conduction vibration. More specifically, the vibration output structure is an opening part provided to the mobile telephone. 
     According to a further specific feature, there is a vibration conduction unit connected to the surface of the primary conduction vibration direction of the cartilage conduction vibration source and exposed from the opening part. An audio signal can thereby be effectively guided to the ear cartilage from the cartilage conduction vibration without the design of the outer surface of the mobile telephone being compromised. 
     According to another specific feature, an elastic body is provided between the vibration conduction unit and the opening part. Useless vibration of the cartilage conduction vibration source can thereby be prevented from being conducted to the mobile telephone without the design of the outer surface of the mobile telephone being compromised. 
     According to another specific feature, an output structure is provided to the upper corner parts of the mobile telephone. An audio signal can thereby be effectively guided from the cartilage conduction vibration to the tragus or other part of the ear cartilage due to the natural manner in which the mobile telephone is held. 
     According to another specific feature, the output structure is provided to the side surface parts of the mobile telephone. An audio signal can thereby be effectively guided from the cartilage conduction vibration to the tragus or other part of the ear cartilage even while contact with the cheek or the like can be prevented from fouling the display surface or other element of the mobile telephone. 
     According to a specific feature, the cartilage conduction vibration source is a piezoelectric bimorph element, where a hold in accordance with the structure and vibration properties of the piezoelectric bimorph element makes it possible to effectively guide an audio signal to the ear cartilage and to prevent useless vibration of the cartilage conduction vibration source from being conducted to the mobile telephone. 
     According to a more specific feature, the primary vibration direction is avoided and the middle part of the cartilage conduction vibration source is held. It is thereby possible to effectively guide an audio signal to the ear cartilage, and also to prevent useless vibration of the cartilage conduction vibration source from being conducted to the mobile telephone. 
     According to another feature, there is provided a mobile telephone characterized by comprising: a cartilage conduction vibration source having a primary vibration surface and an outer surface substantially orthogonal thereto, the cartilage conduction vibration source being adapted to guide an audio signal to the ear cartilage; a holding structure for holding the cartilage conduction vibration source at a ridge between the primary vibration surface and the outer surface; and an audio signal input unit for inputting an audio signal to the cartilage conduction vibration source. An audio signal can thereby be effectively guided to the ear cartilage, and also useless vibration of the cartilage conduction vibration source can be prevented from being conducted to the mobile telephone. 
     According to another feature, there is provided a mobile telephone characterized by comprising: a cartilage conduction vibration source for guiding an audio signal to the ear cartilage; a holding structure having a concave and convex surface for holding the cartilage conduction vibration source; and an audio signal input unit for inputting an audio signal to the cartilage conduction vibration source. An audio signal can thereby be effectively guided to the ear cartilage, and also useless vibration of the cartilage conduction vibration source can be prevented from being conducted to the mobile telephone. 
     Tenth Technical Feature 
     A tenth technical feature disclosed in the present specification provides a vibration element characterized in that an electrode is provided to the middle part of the longitudinal direction. The vibration element can thereby be electrically connected at the middle part of the longitudinal direction, and both ends of the vibration element can thereby be released from the burden of an electrical connection. According to a specific feature, the vibration element includes: a metal sheet; piezoelectric ceramic sheets provided to both sides of the metal sheet; and a resin for covering the periphery thereof, wherein the electrode includes a first electrode pulled out to the surface of the resin from the middle part of the longitudinal direction of the metal sheet, and a second electrode pulled out to the surface of the resin in the vicinity of the first electrode from each of the piezoelectric ceramic sheets. 
     According to another specific feature, the electrodes are pulled out on the surface of the vibration direction of the vibration element. According to another specific feature, the electrodes are pulled from the surface of the resin in the direction substantially orthogonal to the metal sheet and the piezoelectric ceramic sheets. According to yet another specific feature, the resin of the vibration element includes a primary vibration direction surface substantially parallel to the metal sheet and the piezoelectric ceramic sheets and also a non-vibration direction surface substantially orthogonal thereto, and the electrodes are pulled out from such a primarily vibration direction surface of the resin. According to another specific feature, the electrodes are pulled out to the surface of the resin upon being curved substantially 90° within the resin. These features are suitable for support the vibration element from the non-vibration direction. 
     According to another specific feature, there is provided a mobile telephone in which the above-described vibration element is supported on the middle part of the longitudinal direction. This makes it possible to achieve a mobile telephone capable of transmitting the vibration from both ends of the vibration element to the ear cartilage and the like by, for example, cartilage conduction. According to a more specific feature, the vibration element is sandwiched and supported at the middle part of the longitudinal direction from the direction substantially parallel to the metal sheet and piezoelectric ceramic sheets of the piezoelectric bimorph elements. It is thereby made possible to hold the vibration element in the state where less vibration is conducted to the mobile telephone. 
     According to a more specific feature of the mobile telephone described above, vibration conductors are provided to both ends of the vibration element. According to a further specific feature, the vibration conductors are provided to the vicinity of the corners of the mobile telephone. Vibration can thereby be readily conducted to the ear cartilage. 
     According to another specific feature of the mobile telephone described above, the vibration conductors are provided to the side surfaces of the mobile telephone. The front surface of the mobile telephone, to which a display surface or the like is provided, can thereby be prevented from becoming fouled due to contact with the cheek. According to a more specific feature, the vibration conductors assume a long shape along the side surfaces of the mobile telephone. It is thereby possible to obviate the need to strictly select the position to be held against the ear and to permit contact at many points. 
     According to another feature, there is provided a mobile telephone that is guarded at the corners of the outer wall of the body, the mobile telephone including vibration units provided in the vicinity of the corners. The corners of the outer wall of the mobile telephone are suitable for obtaining cartilage conduction by being held up against the ear cartilage, but are conversely also always susceptible to collision with an external unit. According to the configuration described above, cartilage conduction to, for example, the tragus or other part of the ear cartilage is made readily possible while there is also a guard against collision from an external unit. 
     According to another feature, there is provided a mobile telephone including a pair of vibration conductors having a long shape along the side surfaces of the mobile telephone, each of the vibration conductors being provided so as to be substantially orthogonal to both ends of the longitudinal direction of the vibration element. It is thereby possible to make use of the vibration of both ends of the vibration element and to use the long regions of the two side surfaces of the mobile telephone as vibration sources for cartilage conduction. 
     According to yet another feature, there is provided a mobile telephone having a pair of vibration elements having a long shape, each of which elements provided along the two side surfaces of the mobile telephone. It is thereby possible to use the long regions of the two side surfaces of the mobile telephone as vibration sources for cartilage conduction while also independently controlling the respective vibrations of both sides. 
     According to yet another feature, there is provided a mobile telephone including: a vibration element having a long shape provided along one side surface of the mobile telephone, and a holding unit provided to the side surface of the side opposite the side surface to which the vibration element is provided. It is thereby possible to clearly understand which side is the cartilage conduction vibration source. 
     There is provided a mobile telephone including: a vibration element provided to the vicinity of a top side of the mobile telephone; and an elastic vibration conductor for covering the vibration element and forming the top side of the mobile telephone. Cartilage conduction can thereby be obtained from contact with the ear irrespective of being the front surface, rear surface, or side surface in the vicinity of the top side of the mobile telephone. 
     Eleventh Technical Feature 
     An eleventh technical feature disclosed in the present specification provides a mobile telephone comprising a cartilage conduction vibration unit supported inside a chassis structure and is adapted to conduct cartilage conduction vibration to the surface of the chassis structure. It is thereby possible to hold up any place of the surface of the mobile telephone against the ear cartilage and listen to sound by cartilage conduction. There is also greater freedom in the manner in which the cartilage conduction vibration unit is held, and the holding structure is also simplified. 
     According to a specific feature, the surface of the chassis structure has a surface to made to vibrate, and the cartilage conduction vibration unit is held within the chassis structure such that the primary vibration direction thereof is in the direction substantially orthogonal to the surface made to vibrate. Vibration can thereby be effectively conducted to the surface made to vibrate intended for cartilage conduction. According to a more specific feature, the cartilage conduction vibration unit has a piezoelectric bimorph element including a metal sheet, the metal sheet being held in the direction substantially parallel to the surface made to vibrate. The main vibration direction of the cartilage conduction vibration unit can thereby be made to be the direction substantially orthogonal to the surface to be vibrated. 
     According to a further specific feature, the mobile telephone includes a display surface, and the cartilage conduction vibration unit is held such that the primary vibration direction thereof is substantially orthogonal to the display surface. The display surface on the mobile telephone or the rear surface thereof can thereby be made to vibrate effectively, and it is thereby possible to bring the mobile telephone up against the ear cartilage over a broad range. According to a further specific feature, the display surface has a touch panel operation surface, and the cartilage conduction vibration unit has a dual purpose as a vibration source for feedback for the sensation of touch panel operation. 
     According to another specific feature, the cartilage conduction vibration unit is held such that the primary vibration direction thereof is in the direction substantially orthogonal to a side surface of the mobile telephone. The side surface of the mobile telephone can thereby be made to vibrate effectively, and effective cartilage conduction can thereby be obtained even while the display surface is prevented from coming into contact with the cheek and becoming fouled. 
     According to another feature, there is included an impact detection surface, wherein the cartilage conduction vibration unit is held within the chassis structure such that the primary vibration direction thereof is in the direction substantially orthogonal to the impact detection surface. The cartilage conduction vibration unit can thereby be given the dual purpose of effectively detecting impact. 
     According to another feature, the cartilage conduction vibration unit has a dual purpose as a vibration source for providing notification of an incoming call. In such a case, because the vibration of the cartilage conduction vibration unit is conducted to all locations on the surface of the mobile telephone, effective notification of an incoming call can be provided. 
     According to another feature, the cartilage conduction vibration unit is held rigidly within the chassis structure. According to a further specific feature, the cartilage conduction vibration unit is held directly to the chassis structure. These features simplify the holding structure of the cartilage conduction vibration unit and are suitable for effectively transmitting vibration. 
     According to another feature, the mobile telephone includes a horizontal stationary state detection unit, the vibration of the cartilage conduction vibration unit being stopped whenever a horizontal stationary state has been detected. It is thereby possible to prevent the occurrence of uncomfortable vibration noise at times such as when the mobile telephone is placed on a desk during a telephone call. 
     According to further specific feature, the mobile telephone includes a touch panel operation surface, wherein the cartilage conduction vibration unit has a dual purpose as a vibration source for feedback for the sensation of a touch panel operation, and the vibration for feedback for the sensation of a touch panel operation in the cartilage conduction vibration unit is not stopped even when the horizontal stationary state is detected. According to another specific feature, the cartilage conduction vibration unit serves a dual purpose for an impact detection function, and the impact detection function in the cartilage conduction vibration unit is not stopped even when the horizontal stationary state is detected. These features are suitable for smooth GUI operation. 
     According to another further specific feature, the cartilage conduction vibration unit serves a dual purpose as a vibration source for providing notification of an incoming call, and the vibration for providing notification of an incoming call in the cartilage conduction vibration unit is not stopped even when the horizontal stationary state is detected. This feature is suitable for accurately providing notification of an incoming call. 
     Twelfth Technical Feature 
     A twelfth technical feature disclosed in the present specification provides a mobile telephone comprising: a chassis structure having a display surface; and a cartilage conduction vibration unit supported in the chassis structure so as to have a primary vibration surface inclined relative to the display surface. Vibration for cartilage conduction can thereby be conducted to the chassis structure from the direction of incline relative to the display surface. 
     According to a specific feature, the chassis structure includes an inclined surface parallel to the primary vibration surface. The inclined surface can thereby be brought into contact with the ear cartilage to obtain effective cartilage conduction even while fouling due to the display surface coming into contact with the cheek can be prevented, and a vibration component from the display surface or back surface of the mobile telephone can thereby also be obtained. According to a more specific feature, the chassis structure has a side surface orthogonal to the display surface, wherein an inclined plane is provided between the side surface and the surface parallel to the display surface. The inclined surface can thereby be provided with a design in which a box-type mobile telephone is beveled. 
     According to another specific feature, the chassis structure has a cylindrical surface containing the cartilage conduction vibration unit. It is thereby possible to obtain cartilage conduction by bringing the ear cartilage up against the cylindrical surface and a desired position on the display surface or back surface, and also possible thereby to bring the cylindrical surface into contact with the ear cartilage to effectively obtain cartilage conduction in the state where the display surface is not in contact with the face. 
     According to yet another specific feature, the chassis structure includes a side surface orthogonal to the display surface, and the vibration of the primary vibration surface in the cartilage conduction vibration unit is transmitted to a side surface and to the surface parallel to the display surface. It is thereby possible to obtain cartilage conduction in any case where either the side surface or the surface parallel to the display surface is brought into contact with the ear cartilage. 
     According to another specific feature, the chassis structure has an upper surface orthogonal to the display surface, and the vibration of the primary vibration surface in the cartilage conduction vibration unit is transmitted to the surface parallel to the display surface and to the upper surface. It is thereby possible to obtain cartilage conduction in any case where either the upper surface or the surface parallel to the display surface is brought into contact with the ear cartilage. In such a case, the vibration of the upper surface is suitable for contact in the state where the mobile telephone is pushed up against the ear cartilage while bringing the display surface into contact with the face is being avoided, and also for obtaining the earplug bone conduction effect by pushing stronger to block the external auditory meatus with the tragus. An example of the incline of the primary vibration surface in the cartilage conduction vibration unit is the range of about 30° to 60° relative to the display surface. 
     According to another specific feature, the vibration of both sides of a pair of opposing primary vibration surfaces in the cartilage conduction vibration unit is transmitted to the chassis structure. The vibration of the pair of primary vibration surfaces of the cartilage conduction vibration unit is thereby effectively utilized. According to further specific feature, the chassis structure has a side surface or upper surface orthogonal to the display surface, and the vibration of both sides of the primary vibration surfaces in the cartilage conduction vibration unit is respectively transmitted to the side surface or upper surface and to the surface parallel to the display surface. The vibration of the pair of primary vibration surfaces of the cartilage conduction vibration unit is thereby utilized as vibration sources having opposite directions. The positions to which the vibration of the pair of primary vibration surfaces is transmitted may be mutually opposing portions of the primary vibration surfaces, but the configuration may also be such that the vibration is respectively transmitted to the side surface or upper surface and to the surface parallel to the display surface from mutually crossing positions. 
     According to another feature, there is provided a mobile telephone comprising: a chassis structure, and a cartilage conduction vibration unit in which vibration is unrestrictedly permitted in a part of the primary vibration surface and in which another part of the primary vibration surface is supported within the chassis structure. It is thereby possible for the vibration of the cartilage conduction vibration unit to be effectively transmitted to the chassis structure while a loss in the freedom of vibration thereof is avoided. 
     According to a specific feature, the primary vibration surface at the middle part of the cartilage conduction vibration unit is supported in the chassis structure, and vibration is unrestrictedly permitted in the primary vibration surface at both end parts of the cartilage conduction vibration unit. The middle part at which support occurs may be the middle part of the cartilage conduction vibration unit, but when the behavior during the implementation of the cartilage conduction vibration unit lacks left-right symmetry, in order to compensate therefor, the configuration may also be such that the primary vibration surface is supported in the chassis structure at an off-center middle part. 
     According to another specific feature, a plurality of portions of the primary vibration surface of the cartilage conduction vibration unit is supported in the chassis structure. According to a more specific feature, the configuration is such that the primary vibration surfaces at both end parts of the cartilage conduction vibration unit are each supported in the chassis structure, and vibration is unrestrictedly permitted at the primary vibration surface in the middle part of the cartilage conduction vibration unit. 
     According to yet another feature, there is provided a mobile telephone comprising: a chassis structure; and a cartilage conduction vibration unit supported within the chassis structure by the interposition of a vibration conduction elastic body between the primary vibration surfaces. It is thereby possible for the vibration of the cartilage conduction vibration unit to be effectively transmitted to the chassis structure while a loss in the freedom of vibration thereof is avoided. 
     Thirteenth Technical Feature 
     A thirteenth technical feature disclosed in the present specification provides a mobile telephone configured such that a part of the cartilage conduction vibration unit is supported on the inside of the chassis in the vicinity of a corner part of the chassis and another part vibrates unrestrictedly, whereby the vibration of the cartilage conduction vibration unit is transmitted to the corner part of the chassis. The corner part can thereby effectively be made to vibrate while a structure in which the corner part would be susceptible to collision is avoided. 
     According to a specific feature, the cartilage conduction vibration unit is supported on the inside of the upper surface of the chassis at the vicinity of the corner part of the chassis. According to another specific feature, the cartilage conduction vibration unit is supported on the inside of a side surface of the chassis in the vicinity of the corner part of the chassis. According to yet another feature, the cartilage conduction vibration unit is supported on the inside of the front surface of the chassis in the vicinity of the corner part of the chassis. The features above can also be combined as appropriate, in terms of the manner in which the cartilage conduction vibration unit is supported. 
     According to another specific feature, the cartilage conduction vibration unit has an electrical terminal and is supported such that the vicinity of the electrical terminal vibrates unrestrictedly. The cartilage conduction vibration unit can thereby be supported at a position of the chassis closer to the inside of the corner part and the display surface at the corner part can thereby effectively be made to vibrate, without there being any hindrance to the presence of the electrical terminal. 
     According to another specific feature, the cartilage conduction vibration unit is supported such that the primary vibration direction thereof is perpendicular to the upper surface of the chassis. According to yet another feature, the cartilage conduction vibration unit is supported such that the primary vibration direction thereof is perpendicular to a side surface of the chassis. These features make it possible to adopt a configuration such that the vibration is more effective closer to the upper surface or closer to the side surface of the corner part of the chassis. According to yet another specific feature, the cartilage conduction vibration unit is supported such that the primary vibration thereof is perpendicular to the front surface of the chassis. It is thereby possible to adopt a configuration such that the vibration is more effective closer to the front surface of the corner part of the chassis. According to yet another feature, the cartilage conduction vibration unit is supported such that the primary vibration direction thereof is inclined relative to the front surface of the chassis. It is thereby possible allocate vibration components to the front surface and to the surface orthogonal thereto. 
     According to another feature, a circuit for the cartilage conduction vibration unit is supported on the inside of the chassis as a vibration unit integrated with the cartilage conduction vibration unit. It is thereby possible to configure the entirety of the cartilage conduction vibration unit and the circuit related thereto as a vibration unit. 
     According to a more specific feature, the cartilage conduction vibration unit has an electrical terminal, and the circuit for the cartilage conduction vibration unit is arranged in the vicinity of the electrical terminal. It is thereby possible to make effective use of the space in the vicinity of the electrical terminal to configure the vibration unit. According to a more specific feature, the portion of the vibration unit in the vicinity of the electrical terminal is supported. The portion to which the electrical terminal is not provided can thereby be made to unrestrictedly vibrate. 
     According to another feature, there is provided a mobile telephone configured such that the part of the cartilage conduction vibration unit to which the electrical terminal is not provided is supported on the inside of the chassis, and the other part to which the electrical terminal is provided is made to unrestrictedly vibrate, whereby the vibration of the cartilage conduction vibration unit is transmitted to the exterior of the chassis. The cartilage conduction vibration unit can thereby be supported at a position of the chassis closer to the inside of the corner part and the display surface at the corner part can thereby effectively be made to vibrate, without there being any hindrance to the presence of the electrical terminal. 
     According to another feature, there is provided a vibration unit characterized by the integration of a cartilage conduction vibration unit having an electrical unit with a circuit for the cartilage conduction vibration unit arranged in the vicinity of the electrical terminal. It is thereby possible to make effective use of the space in the vicinity of the electrical terminal to configure the vibration unit. 
     According to a specific feature, the circuit has an amplifier for the cartilage conduction vibration unit. The cartilage conduction vibration unit can thereby be effectively supported without the use of the space around the cartilage conduction vibration unit, and the cartilage conduction vibration unit can also thereby be made to vibration efficiently. 
     According to a specific feature, the circuit has an adjustment unit to electrically compensate for the variances of the cartilage conduction vibration unit. The cartilage conduction vibration unit can thereby be effectively supported without the use of the space around the cartilage conduction vibration unit, and performance can also thereby be maintained relative to the variances in the cartilage conduction vibration unit. 
     Fourteenth Technical Feature 
     A fourteenth technical feature disclosed in the present specification provides a mobile telephone in which a part of the cartilage conduction vibration unit is supported by the inside of an elastic body, and the outside of the elastic body is arranged at a corner part of the chassis. The freedom of the cartilage conduction vibration unit to vibrate can thereby be ensured, and the vibration thereof can thereby be efficiently guided to the corner part of the chassis for cartilage conduction by contact with the ear. 
     According to a specific feature, in the mobile telephone, the other part of the cartilage conduction vibration unit is supported by the inside of a second elastic body, and the outside of the second elastic body is arranged at another corner part of the chassis. The cartilage conduction vibration unit can thereby be more reliably supported while the freedom of the cartilage conduction vibration unit to vibrate can be ensured, and also the respective vibrations from both of the support units can thereby be efficiently guided to the corner parts of the chassis for cartilage conduction by contact with the ear. 
     According to a further specific feature, in the mobile telephone, the cartilage conduction vibration unit is shaped to have two end parts, the two end parts of the cartilage conduction vibration unit each being supported on the insides of the elastic body and second elastic body, and the outsides of the elastic body and the second elastic body are each arranged at opposite corner parts of the chassis. The two end parts of the cartilage conduction vibration unit can thereby be reliably supported and the freedom of both end parts to vibrate can be ensured to a certain degree by the support of the elastic bodies, and also the vibration of both ends can thereby be transmitted for cartilage conduction from either of the opposite corner parts of the chassis. 
     According to another technical feature, the cartilage conduction vibration unit has an electrical terminal, and one of either of the elastic body or the second elastic body includes an electrical terminal and supports the cartilage conduction vibration unit. It is thereby possible to reliably support the electrical terminal, including the connective wiring thereof, and the cartilage conduction vibration unit even while the freedom thereof to vibrate is ensured to a certain degree, and also thereby possible to also transmit vibration for cartilage conduction from the portion at which the electrical terminal is found. 
     According to another specific feature, the cartilage conduction vibration unit is eccentric between a corner part and another corner part. It is thereby possible to provide compensation for the imbalance of the cartilage conduction vibration unit, and also the layout of the various parts inside the mobile telephone can be designed with a greater degree of freedom. 
     According to another specific feature, the elastic body is formed with a material having an acoustic impedance approximating that of the ear cartilage. Effective cartilage conduction can thereby be obtained even while the freedom to vibrate is ensured. 
     According to another specific feature, in the mobile telephone, elastic bodies are also arranged at two other corner parts of the chassis where the cartilage conduction vibration unit is not arranged and are configured together with the elastic body at the corner part of the chassis where the cartilage conduction vibration unit is arranged so as to attenuate collision from the exterior unit to the four corners of the mobile telephone. The elastic bodies can thereby be given a dual purpose also as protectors for attenuating collision to the corner parts. This feature makes use of the elastic bodies at the corner parts for the dual objectives of appropriately making use of the corner parts of the mobile telephone to make contact with the ear for cartilage conduction and also protecting the corner parts of the mobile telephone, which are susceptible to collision. According to another specific feature, when the cartilage conduction vibration unit is supported such that the primary vibration direction thereof is orthogonal to the front surface of the chassis, the mobile telephone can be brought into contact with the ear for cartilage conduction without any change in the level of comfort experienced with a normal telephone call. 
     According to another feature, there is provided a mobile telephone in which a very slight stepped concavity is provided to the surface of the mobile telephone and the cartilage conduction vibration unit is arranged on the base surface of the concavity. It is thereby possible to protect the cartilage conduction vibration unit from a collision to the mobile telephone from an external unit, and also thereby possible to use the elastic deformation thereof to readily bring the cartilage conduction vibration unit into contact with the ear cartilage. According to a specific feature, the arrangement is such that the vibration surface of the cartilage conduction vibration unit is positioned on the base surface of the concavity, thus achieving efficient cartilage conduction. According to a more specific feature, a protective layer is provided to the vibration surface; wherever possible, the ear cartilage is brought into direct contact with the vibration surface, and damage to the vibration surface is prevented. According to another specific feature, the concavity is provided to a side surface of the mobile telephone, whereby the advantages of having the concavity can suitably be enjoyed. 
     According to another feature, there is provided a mobile telephone provided with a plurality of cartilage conduction vibration units having primary vibration surfaces which are not mutually parallel. Effective cartilage conduction is thereby possible in a plurality of directions. According to a specific feature, the primary vibration surface of one of the plurality of cartilage conduction vibration units is substantially parallel to a side surface of the mobile telephone, and the primary vibration surface of another one of the plurality of cartilage conduction vibration units is substantially parallel to the front surface of the mobile telephone. Cartilage conduction from the side surface, which is very advantageous, is thereby possible, as is cartilage conduction from the front surface, which is no less comfortable than when a mobile telephone is normally used. 
     According to another specific feature, an arrangement is employed in which the cartilage conduction vibration units are mutually parallel in the longitudinal direction. According to yet another specific feature, an arrangement is employed in which the cartilage conduction vibration units are not mutually parallel in the longitudinal direction. 
     Fifteenth Technical Feature 
     A fifteenth technical feature disclosed in the present specification provides a mobile telephone comprising: a plurality of elastic bodies arranged at each of a plurality of corner parts of the chassis; and cartilage conduction vibration units provided to each of the plurality of elastic bodies. There is thereby provided a mobile telephone in which the corner parts of the mobile telephone can be brought up against the ear cartilage for cartilage conduction and in which the cartilage conduction vibration units arranged at the corner parts can be protected from collision with an external unit. 
     According to a specific feature, the cartilage conduction vibration units are provided to the elastic bodies so as not to be exposed at the outer surfaces of the mobile telephone. According to a more specific feature, each of the cartilage conduction vibration units is embedded in the elastic bodies. According to yet another specific feature, each of the cartilage conduction vibration units is provided to the insides of the elastic bodies. 
     According to another specific feature, the plurality of cartilage conduction vibration units provided to each of the elastic bodies is given respectively different vibration directions. It is thereby possible to obtain favorable cartilage conduction whenever an elastic body is held to the ear cartilage from different directions. According to a more specific feature, the cartilage conduction vibration units can be controlled mutually independently. 
     According to another specific feature, the cartilage conduction vibration units provided to the elastic bodies are electromagnetic vibrators. An electromagnetic vibrator, similarly with respect to a piezoelectric bimorph element, is an example of an element suitable for providing a vibration source in the cartilage conduction vibration units. 
     According to another feature, there is provided a mobile telephone comprising elastic bodies arranged on the chassis and cartilage conduction vibration units provided to the elastic bodies, wherein the elastic bodies and the cartilage conduction vibration units are configured as replaceable unit parts. It is thereby also possible, among other possibilities, to facilitate replacing the elastic bodies and cartilage conduction vibration units, and to provide a product having different cartilage conduction vibration units while other parts are essentially the same. 
     According to another feature, there is provided a mobile telephone comprising: a plurality of cartilage conduction vibration units provided to the chassis and given different vibration directions; and a controller for independently controlling each of the plurality of cartilage conduction vibration units. It is thereby possible to obtain favorable cartilage conduction whenever an elastic body is held to the ear cartilage from different directions. According to a more specific feature, the plurality of provided cartilage conduction vibration units is controlled in accordance with the posture of the mobile telephone, and control in accordance with the direction in which an elastic body is held against the ear becomes possible. 
     According to another feature, there is provided a mobile telephone comprising: elastic bodies arranged on the chassis and including unrestrictedly vibrating parts where vibration is not controlled; and cartilage conduction vibration units provided to the unrestrictedly vibrating parts of the elastic bodies. The vibration of the cartilage conduction vibration units is thereby more favorably transmitted to the elastic bodies. 
     According to a specific feature, the unrestrictedly vibrating parts are elongated parts elongated to the inside of the chassis. It is thereby possible to appropriately hold the cartilage conduction vibration units within the mobile telephone even while vibration can be favorably transmitted. 
     According to a specific feature, the unrestrictedly vibrating parts face a window unit provided to the chassis. The vibration of the cartilage conduction vibration units can thereby be favorably transmitted via the window unit. According to a more specific feature, the unrestrictedly vibrating parts cover the window unit and have a rear surface facing the window unit, the cartilage conduction vibration units being provided to the rear surface. The vibration of the cartilage conduction vibration units provided to the inside of the mobile telephone can thereby be favorably transmitted to the elastic bodies via the window unit. 
     According to another feature, there is provided a mobile telephone comprising: elastic bodies arranged on a chassis; cartilage conduction vibration units provided to the elastic units; and balancers provided to the cartilage conduction vibration units. It is thereby possible to adjust the acoustic properties of the cartilage conduction vibration units transmitted to the elastic bodies. 
     Sixteenth Technical Feature 
     A sixteenth technical feature disclosed in the present specification provides a mobile telephone comprising: a cartilage conduction vibration unit; an air conduction generation unit; and selection means for making a selection between a state for generating, and a state for not generating, vibration from the air conduction generation unit. A variety of different uses are thereby made possible, and the ability to select the state for not generating vibration from the air conduction generation unit permits usage adapted to take the surroundings into consideration and/or adapted for privacy protection. The air conduction generation unit may also be configured so as to have a hollow box structure, according to need, in a case where there is a desire for vigorously generated air conduction. 
     According to a specific feature, the air conduction generation unit is configured such that the air conduction generation unit is made to vibrate by the transmission of the vibration of the cartilage conduction vibration unit, and the transmission of vibration from the cartilage conduction vibration unit is cut off whenever the selection means is used to select the state for not generating vibration from the air conduction generation unit. It is thereby made possible to select between a state for generating, and a state for not generating, vibration from the air conduction generation unit using the cartilage conduction vibration unit as a vibration source. 
     According to a more specific feature, the mobile telephone includes a vibration conductor for relaying the vibration of the cartilage conduction vibration unit to the air conduction vibration unit, and the relay of vibration to the air conduction generation unit is cut off whenever the selection means is used to select the state for not generating vibration from the air conduction generation unit. In the case where such a vibration conductor is employed, it becomes possible to select between a state for generating, and a state for not generating, vibration from the air conduction generation unit even though the cartilage conduction vibration unit and the air conduction generation unit are affixed together. 
     According to another specific embodiment, there is a sliding function by which the selection means can slide between a position for generating, and a position for not generating, the vibration from the air conduction generation unit. According to yet another specific feature, there is a rotation function by which the selection means can be rotated between a position for generating, and a position for not generating, the vibration from the air conduction generation unit. In the cases where a mobile function is employed, it is also possible to configure such that at least a part of at least one of either the cartilage conduction vibration unit or the air conduction generation unit can be moved by the selection means. 
     According to another specific feature, the air conduction generation unit includes a vibration source, and the selection means stops the generation of vibration from the vibration source of the air conduction generation unit in the state for not generating the vibration from the air conduction generation unit. It is thereby possible to select whether or not air conduction is to be generated even in a configuration lacking moveable parts. 
     According to another specific feature, there is an environmental noise detection unit, and the selection means automatically selects the state for not generating the vibration from the air conduction generation unit whenever the environmental noise detected by the environmental noise detection unit is at or below a predetermined loudness. It is thereby possible to automatically select a state adapted to take the surroundings into consideration and/or adapted for privacy protection in the state where the surroundings are silent. 
     According to another feature, there is provided a mobile telephone comprising: an audio generation unit; a pressure sensor for detecting pressure on the audio generation unit; and an automatic adjustment unit for automatically changing the state of audio generated from the audio generation unit on the basis of the pressure detected by the pressure sensor. It is thereby possible to automatically change the state of audio generated from the audio generation unit on the basis of the natural operation of pressing the audio generation unit up against the ear. According to a specific feature, the audio generation unit is an air conduction speaker. According to another specific feature, the automatic adjustment unit automatically adjusts the volume or acoustics of the audio generated from the audio generation unit. 
     According to another specific feature, the automatic adjustment unit changes the state of audio generated in one direction from an initial state and maintains the changed state in accordance with an increase in pressure from the pressure sensor, and returns the state of audio generated to the initial state in accordance with a predetermined reduction or greater reduction in pressure from the pressure sensor. It is thereby possible to change the state of audio generated on the basis of a natural operation, and also to avoid an unintentional change in the state of audio generated. According to another specific feature, the automatic adjustment unit automatically changes the state of audio generated from the audio generation unit when a change in pressure from the pressure sensor continues for a predetermined period of time or longer, and does not respond to a change in pressure that does not meet the predetermined period of time. It is thereby possible to avoid an unintentional change in the state of audio generated. 
     According to another feature, there is provided a mobile telephone characterized by comprising a right ear audio generation unit, and a left ear audio generation unit arranged at a different position than that of the right ear audio generation unit. It is thereby possible to achieve a natural posture for holding the mobile telephone up against the ear. According to a specific feature, the right ear audio generation unit and the left ear audio generation unit are each arranged at two corner parts at the upper part of the mobile telephone. According to another specific feature, a large-screen display unit is arranged on the same surface on which the right ear audio generation unit and the left ear audio generation unit are arranged. According to another specific feature, each of the right ear audio generation unit and the left ear audio generation unit air conduction speakers. 
     According to another feature, there is provided a mobile telephone in which a large-screen display unit is provided, and air conduction speakers are provided to the corner parts at the upper part of the surface to which the large-screen display unit is provided. It is thereby possible to achieve a natural posture for effectively holding the air conduction speakers against the ear even while interference between the large-screen display unit and the face is avoided. 
     Seventeenth Technical Feature 
     A seventeenth technical feature disclosed in the present specification provides a mobile telephone comprising: a pair of cartilage conduction vibration units; a sound source signal unit; and drive units for driving each of the pair of cartilage conduction vibration units in a mutually phase-inverted waveform on the basis of a sound source signal from the sound source signal unit. It is thereby possible to obtain cartilage conduction by contact with each of the pair of cartilage conduction vibration units, and also thereby possible to substantially eliminate air conduction that is based on the vibration of the pair of cartilage conduction vibration units. 
     According to a specific feature, the pair of cartilage conduction vibration units is provided to each of the pair of corner parts at the upper part of the mobile telephone, which are suitable for contact against the ear cartilage. According to a further specific feature, elastic body units are provided to the pair of corner parts, and the pair of cartilage conduction vibration units is supported on the elastic body units. It is thereby possible to protect the cartilage conduction vibration units from collision with an external unit. 
     According to a further specific feature, the outer surface of the elastic body units is beveled so as to have a smoothly convex shape, thus achieving suitable contact with the ear cartilage. According to another specific feature, the cartilage conduction vibration units include a piezoelectric bimorph element or an electromagnetic vibrator. 
     According to another specific feature, the drive units are capable of switching between a mode for driving each of the pair of cartilage conduction vibration units in mutually inverted waveforms on the basis of a sound source signal from the sound source signal unit, and a mode for driving each of the pair of cartilage conduction vibration units in mutually identical waveforms on the basis of a sound source signal from the sound source signal unit. It is thereby possible to switch between eliminating and increasing air conduction. 
     According to yet another specific feature, there is an environmental noise detection unit, and the drive units drive each of the pair of the cartilage conduction vibration units in mutually inverted waveforms on the basis of a sound source signal from the sound source signal unit whenever the environmental noise detected by the environmental noise detection unit is at or below a predetermined loudness. It is thereby possible to automatically eliminate air conduction when the environment is silent. 
     According to yet another specific feature, it is possible to adjust the balance for driving each of the pair of cartilage conduction vibration units in mutually inverted waveforms on the basis of a sound source signal from the sound source signal unit. It is thereby possible to effectively eliminate air conduction and also to regulate the state where air conduction is eliminated. 
     According to yet another feature, the drive units are capable of driving only one of the pair of cartilage conduction vibration units. It is thereby possible to avoid driving uselessly when there is no need to eliminate air conduction. 
     According to a more specific feature, the mobile telephone includes an environmental noise detection unit, and the drive units drive each of the pair of cartilage conduction vibration units in mutually inverted waveforms on the basis of a sound source signal from the sound source signal unit whenever the environmental noise detected by the environmental noise detection unit is at or below a predetermined loudness, and drive only one of the pair of cartilage conduction vibration units whenever the environmental noise detected by the environmental noise detection unit is at or above a predetermined loudness. It is thereby possible to cause only the cartilage conduction vibration unit that is in contact with the ear cartilage to vibrate, and in such a state to cause the other cartilage conduction vibration unit to vibrate in an inverted waveform and automatically eliminate air conduction when the environment becomes silent. 
     According to another feature, there is provided a mobile telephone in which the cartilage conduction vibration units are provided to the pair of corner parts at the upper part of the mobile telephone, and the outer surface of the corner parts is beveled so as to have a smoothly convex shape. It is thereby made possible to make contact with the ear cartilage without incurring substantial pain and also possible to comfortably listen by cartilage conduction with the corner parts appropriately fitted to the cartilage around the external auditory meatus. 
     According to another feature, there is provided a mobile telephone comprising: a pair of cartilage conduction vibration units; a sound source signal unit; drive units capable of driving each of the pair of cartilage conduction vibration units on the basis of a sound source signal from the sound source signal unit; a selection unit for selecting a cartilage conduction vibration unit to be driven by a drive unit; and a controller for controlling the waveform inversion of the sound source signal from the sound source signal unit. The pair of cartilage conduction vibration units can thereby be used to achieve a variety of different forms of cartilage conduction. 
     Eighteenth Technical Feature 
     An eighteenth technical feature disclosed in the present specification provides a mobile telephone comprising a surface of the outer wall and a vibration source arranged inward from the surface of the outer wall, wherein when the vibration of the vibration source is transmitted to the surface of the outer wall, and the surface of the outer wall is brought into contact with at least a part of the ear cartilage around the entrance part of the external auditory meatus without making contact with the auricular helix, the sound pressure inside the external auditory meatus at about 1 cm from the entrance part of the external auditory meatus has an increase of at least 10 dB over that in the non-contact state. A mobile telephone in which it is possible to listen to sound by cartilage conduction can thereby be provided. 
     According to another feature, there is provided a mobile telephone comprising an surface of the outer wall and a vibration source arranged inward from the surface of the outer wall, wherein when the vibration of the vibration source is transmitted to the surface of the outer wall, and the surface of the outer wall is brought into contact with at least a part of the ear cartilage around the entrance part of the external auditory meatus without making contact with the auricular helix, the sound pressure inside the external auditory meatus at about 1 cm from the entrance part of the external auditory meatus changes by at least 5 dB due to the change in contact pressure. A mobile telephone by which the volume can be changed by a change in contact pressure during cartilage conduction can thereby be provided. 
     According to another feature, there is provided a mobile telephone comprising an surface of the outer wall and a vibration source arranged inward from the surface of the outer wall, wherein when the vibration of the vibration source is transmitted to the surface of the outer wall, and the entrance part of the external auditory meatus is occluded by the surface of the outer wall being brought into contact with at least a part of the ear cartilage around the entrance part of the external auditory meatus without contact being made with the auricular helix, the sound pressure in the external auditory meatus at about 1 cm from the entrance part of the external auditory meatus has an increase of at least 20 dB compared to the non-contact state. A mobile telephone by which it is possible to listen to sound by the earplug bone conduction effect during cartilage conduction can thereby be provided. 
     According to the specific features above, the sound pressure that is increased or changed is at 1,000 Hz. 
     According to yet another feature, the increase or change in sound pressure is in a state where the output of the vibration source is not changed. The sound pressure is thereby increased or changed without the volume being altered. 
     According to another specific feature, the state where the surface of the outer wall is brought into contact with at least a part of the ear cartilage around the entrance part of the external auditory meatus without making contact with the auricular helix is a state where the surface of the outer wall is brought into contact with the outside of the tragus. According to a more specific feature, the state where the sound pressure in the external auditory meatus at about 1 cm from the entrance part of the external auditory meatus is increased by at least 10 dB when the surface of the outer wall is brought into contact with at least a part of the ear cartilage around the entrance part of the external auditory meatus without making contact with the auricular helix, compared to the non-contact state, is one where the contact pressure of the surface of the outer wall against the outside of the tragus is 250 g. 
     According to another specific feature, the vibration source is arranged such that the vibration thereof is transmitted to the surface of the corner parts of the outer wall, and the state where the surface of the outer wall is brought into contact with at least a part of the ear cartilage around the entrance part of the external auditory meatus without making contact with the auricular helix is a state where the surface of the corner parts of the outer wall is brought into contact with the outside of the tragus. It is thereby possible to achieve contact suitable for obtaining cartilage conduction in the mobile telephone. 
     According to a more specific feature, the corner parts of the outer wall are constituted of a different material from the other portions of the outer wall. According to another more specific feature, the vibration source is either held inside the outer wall at the corner parts of the outer wall or is held inside the corner parts of the outer wall. 
     According to another feature, there is provided a mobile telephone comprising a surface of an outer wall, a vibration source arranged inward from the surface of the outer wall, and volume adjustment means, the vibration of the vibration source being transmitted to the surface of the outer wall and sound being listened to by the contact of the surface of the outer wall with at least a part of the ear cartilage around the entrance part of the external auditory meatus without contact with the auricular helix, wherein: in a room where the noise level (the A-weighted sound pressure level) is 45 dB or less, the mobile telephone being brought into proximity with the entrance part of the external auditory meatus and the surface of the outer wall being arranged so as to not be in contact, the volume is minimized and pure sound at 1,000 HZ is generated from the vibration source, and also narrow-band noise (⅓ octave-band noise) at a marginal level where the pure sound at 1,000 Hz is masked and cannot be heard is generated from a loudspeaker at a position separated from the entrance part of the external auditory meatus by 1 m. When the narrow-band noise at 1,000 Hz is subsequently increased by 10 dB from the marginal level, bringing the surface of the outer wall into contact with at least a part of the ear cartilage around the entrance part of the external auditory meatus without making contact with the auricular helix makes it possible to listen to pure sound at 1,000 Hz without the need to adjust or change the volume adjusting means. A mobile telephone in which the volume can be changed by a change in contact pressure during cartilage conduction can thereby be provided. 
     According to another feature, there is provided a mobile telephone comprising a surface of an outer wall, a vibration source arranged inward from the surface of the outer wall, and volume adjustment means, the vibration of the vibration source being transmitted to the surface of the outer wall and sound being listened to by the contact of the surface of the outer wall with at least a part of the ear cartilage around the entrance part of the external auditory meatus without contact with the auricular helix, wherein: in a room where the noise level (the A-weighted sound pressure level) is 45 dB or less, the mobile telephone being brought into proximity with the entrance part of the external auditory meatus and the surface of the outer wall being arranged so as to not be in contact, the volume is minimized and pure sound at 1,000 HZ is generated from the vibration source, and also narrow-band noise (⅓ octave-band noise) at a marginal level where the pure sound at 1,000 Hz is masked and cannot be heard is generated from a loudspeaker at a position separated from the entrance part of the external auditory meatus by 1 m. When the narrow-band noise at 1,000 Hz is subsequently increased by 20 dB from the marginal level, bringing the surface of the outer wall into contact with at least a part of the ear cartilage around the entrance part of the external auditory meatus without making contact with the auricular helix to occlude the entrance part of the external auditory meatus makes it possible to listen to pure sound at 1,000 Hz without the need to adjust or change the volume adjusting means. 
     Nineteenth Technical Feature 
     A nineteenth technical feature disclosed in the present specification provides a sound output device in which the vibration of a vibration source arranged inward from the surface of an outer wall is transmitted to the surface of the outer wall, and sound is listened to by the contact of the surface of the outer wall with at least a part of the ear cartilage around the entrance part of the external auditory meatus, wherein the vibration source causes there to be generated, from the surface of the outer wall, air conduction of a frequency characteristic trending inversely with respect to the frequency characteristic during cartilage conduction. It is thereby possible for the frequency characteristic during cartilage conduction and the frequency characteristic of the vibration source to be complementary to each other and, as a result, for the frequency characteristic of the sound reaching the tympanic membrane to approach flatness. 
     According to a specific feature, the average air conduction generated by the vibration source from the surface of the outer wall from 500 Hz to 1 kHz is 5 dB less than the average air conduction generated by the vibration source from the surface of the outer wall from 1 kHz to 2.5 kHz. 
     According to another specific feature, the sound output device is provided with an equalizer for correcting the frequency characteristic in consideration of the frequency characteristic specific to cartilage conduction in regard to the vibration source is driven by a sound source signal of the sound source signal output unit. It is thereby made possible for frequency characteristic of the sound reaching the tympanic membrane to approach flatness in consideration of the frequency characteristic of the cartilage conduction. 
     According to a more specific feature, the equalizer corrects for the frequency characteristic, which is different from when the external auditory meatus is in an open state, when the vibration source is driven in the state where the external auditory meatus is occluded. It is thereby made possible for the frequency characteristic of the sound reaching the tympanic membrane to approach flatness in consideration of the frequency characteristic of cartilage conduction during the state where the earplug bone conduction effect occurs. 
     According to another specific feature, there is a low-pass filter for correcting the frequency characteristic in consideration of the frequency characteristic specific to cartilage conduction in terms of the manner in which the vibration source is driven by a sound source signal of the sound source signal output unit. According to a further specific feature, the low-pass filter trims frequencies at 2.5 kHz and higher when the sound output device is used in a mobile telephone. In yet another specific feature, the low-pass filter trims frequencies at 10 kHz and higher when the sound output device is used in an audio device. Concern can thereby be given to the surroundings during, for example, silence. 
     According to another feature, there is provided a sound output device which includes a sound source signal output unit for outputting a sound source signal, a surface of an outer wall, a vibration source arranged inward from the surface of the outer wall and driven by the sound source signal from the sound source signal output unit, and an air conduction generation unit drive by the sound source signal from the sound source signal output unit, wherein the air conduction generated by the transmission of the vibration of the vibration source to the surface of the outer wall has a different frequency characteristic from that of the air conduction generated form the air conduction generation unit, it being possible to listen to sound by direct air conduction generated from the air conduction generation unit or by air conduction through cartilage conduction when the surface of the outer wall is brought into contact with at least a part of the ear cartilage around the entrance part of the external auditory meatus. The uncomfortable change in acoustics depending on the manner in which sound is being listened to can thereby be attenuated. 
     According to another feature, there is provided a sound output device which includes a sound source signal output unit for outputting a sound source signal, a surface of an outer wall, a vibration source arranged inward from the surface of the outer wall and driven by the sound source signal from the sound source signal output unit, and an air conduction generation unit drive by the sound source signal from the sound source signal output unit, wherein the frequency characteristic of the drive signal when the vibration source is driven by the sound source signal is different from the frequency characteristic of the drive signal when the air conduction generation unit is driven by the sound source signal, it being possible to listen to sound by direct air conduction generated from the air conduction generation unit or by air conduction through cartilage conduction when the surface of the outer wall is brought into contact with at least a part of the ear cartilage around the entrance part of the external auditory meatus. The uncomfortable change in acoustics depending on the manner in which sound is being listened to can thereby be attenuated. 
     According to another feature, there is provided a sound output device which includes a vibration source arranged inward from the surface of an outer wall, a sound source signal output unit for outputting a sound source signal, and an equalizer for correcting the frequency characteristic in consideration of the frequency characteristic specific to cartilage conduction in regard to the vibration source being driven by the sound source signal of the sound source signal unit, wherein the vibration of the vibration source is transmitted to the surface of the outer wall, and the surface of the outer wall is brought into contact with at least a part of the ear cartilage around the entrance part of the external auditory meatus, whereby it is possible to listen to sound. It is thereby possible for consideration to be given to the frequency characteristic during cartilage conduction and, as a result, for the frequency characteristic of sound reaching the tympanic membrane to approach flatness. According to a specific feature, the equalizer corrects for the frequency characteristic, which is different from when the external auditory meatus is in an open state, in regard to driving of the vibration source in the state where the external auditory meatus is occluded. According to a more specific feature, the sound output device is provided with a detection unit for detecting whether or not the external auditory meatus is in an occluded state, and the equalizer automatically switches to the state where the frequency characteristic is corrected, on the basis of the detection by the detection unit. According to another more specific feature, the sound output device is provided with a low-pass filter for correcting the frequency characteristic in consideration of the frequency characteristic specific to cartilage conduction in regard to driving of the vibration source by the sound source signal of the sound source signal unit, and, when the equalizer corrects the frequency characteristic in the state where the external auditory meatus is occluded, the state is considered not to be silent, and the low-pass filter is made not to function. 
     According to another feature, there is provided a sound output device which includes a vibration source arranged inward from the surface of an outer wall, a sound source signal output unit for outputting a sound source signal, and a low-pass filter for correcting the frequency characteristic in consideration of the frequency characteristic specific to cartilage conduction in regard to driving of the vibration source by the sound source signal of the sound source signal output unit, wherein the vibration of the vibration source is transmitted to the surface of the outer wall, and the surface of the outer wall is brought into contact with at least a part of the ear cartilage around the entrance part of the external auditory meatus, whereby it is possible to listen to sound. Concern can thereby be given to the surroundings during, for example, silence. According to a specific feature, it is possible to switch between whether or not the low-pass filter is made to function. It is thereby possible to provide support for times of silence and to properly use an emphasis on acoustics. According to a more specific feature, the sound output device is provided with an environmental noise detection unit for detecting environmental noise, and there is an automatic switch for whether or not the low-pass filter is made to function, on the basis of the detection results from the environmental detection unit. 
     According to another feature, there is provided a sound output device which includes a vibration source arranged inward from the surface of an outer wall, and a sound source signal output unit for outputting a sound source signal, wherein the vibration of the vibration source is transmitted to the surface of the outer wall, and the surface of the outer wall is brought into contact with at least a part of the ear cartilage around the entrance part of the external auditory meatus, whereby it is possible to listen to sound; the sound output device being characterized in that the frequency characteristic is different when the external auditory meatus is in an occluded state and when the external auditory meatus is in an open state, in regard to driving of the vibration source by the sound source signal of the sound source signal output unit. It is thereby possible to reduce the discomfort arising from the presence or absence of the earplug bone conduction effect. 
     Twentieth Technical Feature 
     A twentieth technical feature disclosed in the present specification provides a mobile telephone comprising: a cartilage conduction vibration source; an outer surface having no localized projections; a cartilage contact unit on the outer surface, to which the vibration of the cartilage conduction vibration source is transmitted such that the amplitude or the acceleration of the vibration reaches a maximum; and a cartilage non-contact unit on the outer surface exhibiting an amplitude or acceleration of vibration less than that at the cartilage contact unit. The vibration energy of the cartilage conduction vibration source is thereby concentrated on the cartilage contact unit and the dispersion to the cartilage non-contact unit is thereby reduced. The usage of the mobile telephone will also not be hindered, because the cartilage contact unit is set to the outer surface having no localized projections. 
     According to another feature, there is provided a mobile telephone comprising: a cartilage conduction vibration source; an outer surface; a cartilage contact unit on the outer surface, which is set to a position removed from both the central up-down axis and central left-right axis of the outer surface and to which the vibration of the cartilage conduction vibration source is transmitted such that the amplitude or the acceleration of the vibration reaches a maximum; and a cartilage non-contact unit on the outer surface exhibiting an amplitude or acceleration of vibration less than that at the cartilage contact unit. Because the cartilage contact unit is set to a position removed from both the central up-down axis and the central left-right axis of the outer surface, the resulting arrangement is suitable for contact with the ear cartilage at the entrance part of the external auditory meatus. 
     According to a specific feature, the cartilage contact unit is set to a corner part of the upper part of the mobile telephone. The resulting configuration is thereby suitable for bringing the surface of the outer wall into contact with at least a part of the ear cartilage around the entrance part of the external auditory meatus without making contact with the auricular helix. 
     According to a more specific feature, cartilage contact units are set in each of the pair of corner parts at the upper part of the mobile telephone. It is thereby possible to concentrate the vibration energy of the cartilage conduction vibration source on the ear cartilage both when the mobile telephone is held up against the right ear and when the mobile telephone is held up against the left ear. 
     According to another specific feature, the amplitude or the acceleration of vibration in the cartilage non-contact unit is ¼ or less the acceleration of vibration in the cartilage contact unit. The vibration energy of the cartilage conduction vibration source can thereby be concentrated on the cartilage contact unit and the dispersion to the cartilage non-contact unit can thereby be reduced. 
     According to another specific feature, the amplitude or the acceleration of vibration in the cartilage non-contact unit reduces monotonically as the distance from the cartilage contact unit increases. The vibration energy of the cartilage conduction vibration source can thereby be concentrated on the cartilage contact unit and the dispersion to the cartilage non-contact unit can thereby be reduced. 
     According to another feature, there is provided a mobile telephone comprising: a cartilage conduction vibration source; a chassis; a cartilage contact unit for holding the cartilage conduction vibration source so as not to be in contact with the chassis; and an anti-vibration material interposed between the cartilage contact unit and the chassis of the mobile telephone. The vibration energy of the cartilage conduction vibration source can thereby be concentrated on the cartilage contact unit. 
     According to a more specific feature, the aforesaid cartilage contact unit is constituted of a hard material, and the aforesaid anti-vibration material is constituted of an elastic body. The vibration energy of the cartilage conduction vibration source can thereby be concentrated on the cartilage contact unit. 
     As another element for concentrating the vibration energy of the cartilage conduction vibration source onto the cartilage contact unit, it is also suitable: to avoid the primary vibration direction of the cartilage conduction vibration source and support the same on the chassis of the mobile telephone; to reduce the surface area of contact between the cartilage contact unit and the chassis of the mobile telephone supporting the same; to limit the position at which the cartilage conduction vibration source is held to the vicinity of the cartilage contact unit; to make the cartilage contact material of a different material from that of the chassis of the mobile telephone; and the like. In addition to the cases of the independent usage of such elements, it is also possible to employ an appropriate combination of a plurality of elements. 
     According to another feature, there is provided a mobile telephone comprising: a cartilage conduction vibration source; a T-coil; and a controller for preventing the cartilage conduction vibration source from vibrating whenever the T-coil is being used. The greater discomfort that occurs compared to listening to sound using the T-coil is thereby prevented, and the unnecessary consumption of power by cartilage conduction when the T-coil is operating is thereby prevented. In the description above, in a preferred configuration, to prevent accidental conflation where cartilage conduction is turned off in tandem when the T-coil is turned on by a mistaken operation, the T-coil will not turn on unless a special operation is intentionally done. 
     Twenty-First Technical Feature 
     A twenty-first technical feature disclosed in the present specification provides a mobile telephone comprising: a telephone function unit; a cartilage conduction vibration unit; an application processor for controlling the telephone function unit; a power management unit for supplying a plurality of different voltages to the telephone function unit; a drive circuit for driving the cartilage conduction vibration unit on the basis of the power supplied from the power management; and a controller for controlling the power management unit and the drive circuit on the basis of an instruction from the application processor. The cartilage conduction vibration unit can thereby be driven directly, and power voltage can be supplied to the cartilage conduction vibration unit integratedly with the supply of power voltage to the various constituent elements inside the mobile telephone, other integrated forms of control also being possible as well. According to a more specific feature, the power management unit, the drive circuit, and the controller are configured as a single-chip integrated circuit. 
     According to another specific feature, the drive circuit has a boosted-voltage circuit, and the integrated circuit has a connective terminal for external attachment of a condenser for the boosted-voltage circuit. The cartilage conduction vibration element (piezoelectric bimorph) can thereby be driven without the need to add a separate chip for the boosted-voltage circuit. 
     According to another specific feature, the mobile telephone is controlled by a controller and has a cartilage conduction acoustic processing for an audio signal for driving the cartilage conduction vibration unit. It is thereby possible to integrate the control of the power management with the control for acoustic processing. Accordingly, the mobile telephone can be endowed with a suitable cartilage conduction function merely by a normal audio signal being inputted to the integrated IC and the cartilage conduction vibration unit being connected to the integrated IC. According to a more specific feature, the power management unit, the drive circuit, the controller, and the cartilage conduction acoustic signal processing unit are configured as a single-chip integrated circuit. 
     According to another specific feature, the mobile telephone includes a speaker, a microphone, and an analog front-end unit by which the speaker and microphone are connected, the analog front-end unit being controlled by the controller. The output of audio signals can thereby be collectively switched and adjusted. Specifically, the transfer of digital control signals between the integrated IC and the application processor, the digital control signals relating to the functions of the overall mobile telephone inclusive of the functions of the cartilage conduction vibration unit, can be integrated with the transfer of analog audio signals between the integrated IC and the application processor. According to a more specific feature, the analog front-end unit switches between driving the cartilage conduction vibration unit and driving the speaker on the basis of the control by the controller. According to another more specific feature, the power management unit, the drive circuit, the controller, the cartilage conduction acoustic signal processing unit, and the analog front-end unit are configured as a single-chip integrated circuit. 
     According to another feature, there is provided a mobile telephone comprising: a telephone function unit; a cartilage conduction vibration unit; an application processor for controlling the telephone function unit; a power management unit for supplying a plurality of different voltages to the telephone function unit; a cartilage conduction acoustic signal processing unit for an audio signal for driving the cartilage conduction vibration unit; and a controller for controlling the power management unit and the cartilage conduction acoustic signal processing unit on the basis of an instruction from the application processor. The control for acoustic processing relating to cartilage conduction can thereby be integrated with the control for power management. According to a specific feature, the power management unit, the cartilage conduction acoustic signal processing unit, and the controller are configured as a single-chip integrated circuit. 
     According to another specific feature, the mobile telephone has a speaker, a microphone, and an analog front-end unit by which the speaker and microphone are connected, the analog front-end unit being controlled by the controller. The output of audio signals can thereby be collectively switched and adjusted. According to a more specific feature, the analog front-end unit switches between driving the cartilage conduction vibration unit and driving the speaker on the basis of the control by the controller. According to yet another more specific feature, the power management unit, the cartilage conduction acoustic signal processing unit, the controller, and the analog-front end unit are configured as a single-chip integrated circuit. 
     According to another feature, there is provided a single-chip integrated circuit which includes: a power management unit for supplying a plurality of different voltages for telephone functions; a connecting part by which a cartilage conduction vibration element, which is one of the constituent elements of the cartilage conduction vibration unit, is connected; a drive circuit for driving the cartilage conduction vibration unit on the basis of the power supplied from the power management; and a controller for controlling the power management unit and the drive circuit on the basis of digital data from an external unit. The cartilage conduction vibration unit can thereby be driven directly, and power voltage can be supplied to the cartilage conduction vibration unit integratedly with the supply of power voltage to the various constituent elements inside the mobile telephone, it being possible to also integrate the control thereof. 
     According to a specific feature, the drive circuit has a boosted-voltage circuit, and the integrated circuit has a connective terminal for external attachment of a condenser for the boosted-voltage circuit. The cartilage conduction vibration element (piezoelectric bimorph) can thereby be driven merely by the single-chip integrated circuit. 
     According to another specific feature, the single-chip integrated circuit is controlled by the controller and has a cartilage conduction acoustic signal processing unit for an audio signal for driving the cartilage conduction vibration unit. It is thereby possible to integrate the control of the power management with the control for acoustic processing. According to another specific feature, the single-chip integrated circuit includes a connecting part for the speaker, a connecting part for the microphone, and an analog front-end unit connected to each of the connecting parts, the analog front-end unit being controlled by the controller. According to a more specific feature, the analog front-end unit switches between driving the cartilage conduction vibration unit and driving the speaker on the basis of the control by the controller. 
     According to another feature, there is provided a single-chip integrated circuit which includes: a power management unit for supplying a plurality of different voltages for telephone functions; a connecting part by which a cartilage conduction vibration element, which is one of the constituent elements of the cartilage conduction vibration unit, is connected; an audio signal acoustic signal processing unit for an audio signal for driving the cartilage conduction vibration unit; and a controller for controlling the power management unit and the cartilage conduction acoustic signal processing unit on the basis of digital data from an external unit. According to a specific feature, the single-chip integrated circuit includes a connecting part for the speaker, a connecting part for the microphone, and an analog front-end unit connected to each of the connecting parts, the analog front-end unit being controlled by the controller. According to a more specific feature, the analog front-end unit switches between driving the cartilage conduction vibration unit and driving the speaker on the basis of the control by the controller. 
     Twenty-Second Technical Feature 
     A twenty-second technical feature disclosed in the present specification provides a mobile telephone comprising: a cartilage conduction vibration source provided inside a chassis; and an elastic body integrally affixed to and covered by the exterior of the chassis. The vibration of the chassis of the mobile telephone is thereby suppressed and sound leakage due to the generation of air conduction sound is thereby attenuated. According to a specific feature, the mobile telephone has a cartilage conduction unit for conducting the vibration of the cartilage conduction vibration source and for making contact with the ear cartilage, it being thus possible to listen to sound by cartilage conduction even while sound leakage to the surroundings due to the generation of air conduction sound is attenuated. 
     According to a more specific feature, the cartilage conduction unit is an elastic body. The elastic body has an acoustic impedance approximating that of ear cartilage, wherefore it is possible to listen to sound by cartilage conduction even when sound leakage to the surroundings due to the generation of air conduction sound is attenuated. According to a further specific feature, the cartilage conduction unit can be an elastic body integrally affixed to and covered by the exterior of the chassis. More specifically, the cartilage conduction unit can be connected with an elastic body integrally affixed to and covered by the exterior of the chassis. 
     According to another specific feature, the cartilage conduction unit is a rigid body, and the elastic body also covers the cartilage conduction unit. Sound leakage to the surroundings due to the generation of air conduction sound can thereby be attenuated even while favorable cartilage conduction is obtained. According to a more specific feature, the cartilage conduction unit is supported on the chassis via a vibration isolation material, and the transmission of vibrations to the chassis is attenuated. According to a further specific feature, the vibration isolation material is an elastic body of the same material as the elastic body integrally affixed to and covered by the exterior of the chassis. 
     According to another specific feature, the cartilage conduction vibration source is supported on the cartilage conduction unit in a state of non-contact with the chassis, and the direct transmission of vibration from the cartilage conduction vibration source to the chassis is avoided. In the case where priority is given to structural simplicity, it is also possible for the cartilage conduction vibration source to be supported on the chassis. The chassis will then have greater vibration, but such vibration can be attenuated by the elastic body integrally affixed to and covered by the exterior of the chassis. 
     According to another feature, there is provided a mobile telephone comprising: an elastic body integrally affixed to and covered by the exterior of the chassis, and a cartilage conduction vibration source supported by the elastic body in a state of non-contact with the chassis. It is thereby possible to attenuate sound leakage to the surroundings due to the generation of air conduction sound even while avoiding the direct transmission of vibration from the cartilage conduction vibration source to the chassis, and to listen to sound by cartilage conduction. 
     According to a specific feature, the cartilage conduction vibration source is supported on the inside of the elastic body, and the outside of the elastic body at the part supporting the cartilage conduction vibration source serves as a cartilage conduction unit for making contact with the ear cartilage. According to a further specific feature, the cartilage conduction vibration source is supported on the inside of the elastic body via a rigid support unit. 
     According to another specific feature, the mobile telephone has a support structure for supporting the internal configuration of the mobile telephone on the chassis from the inside such that the weight thereof vibrates integrally. The vibration from the interior and the exterior of the chassis of the mobile telephone can thereby be suppressed. 
     According to another feature, there is provided a mobile telephone comprising: a cartilage conduction vibration source provided to the interior of a chassis; and a support structure for supporting the internal configuration of the mobile telephone on the chassis from the inside such that the weight thereof vibrates integrally. The vibration of the chassis of the mobile telephone is thereby suppressed and sound leakage due to the generation of air conduction sound is thereby attenuated. Internal configurations contributing to the above include a battery. 
     According to a specific feature, the mobile telephone has a finely subdividing structure for finely subdividing surplus space of the interior of the chassis. The vibration of the chassis of the mobile telephone can thereby be suppressed and the air inside the chassis prevented from resonating, and the generation of air conduction sound can thereby be attenuated. 
     According to another feature, there is provided a mobile telephone comprising: a cartilage conduction vibration source provided to the interior of a chassis, and a finely subdividing structure for finely subdividing the surplus space of the interior of the chassis. The air inside the chassis can thereby be prevented from resonating, and the generation of air conduction sound can thereby be attenuated. An example of a finely subdividing structure is a barrier wall. Another example of a finely subdividing structure is a nonwoven cloth packed inside the chassis. 
     Twenty-Third Technical Feature 
     A twenty-third technical feature disclosed in the present specification provides a sound output device having: a chassis; a cartilage conduction unit defining a convex face shape on the chassis surface; and a cartilage conduction vibration source for transmitting vibration to the cartilage conduction unit. In so doing, the cartilage conduction unit arranged touching the ear is naturally accommodated within the ear, affording contact with the ear cartilage over a wide surface area. 
     The ear-contacting part of an ordinary telephone handset has a concave face in order to form a closed space to the front of the ear; however, the handset for cartilage conduction according to the present invention conversely has a convex face, providing a natural shape that readily conforms to the ear in the aforedescribed manner. 
     According to a specific feature, the cartilage conduction unit has a convex face shape fitting into a depression of ear having the external auditory meatus opening as the bottom. According to a more specific feature, the cartilage conduction unit has a convex face shape, the apex of which enters the external auditory meatus opening. According to a yet more specific feature, the cartilage conduction unit has a conical shape. According to another yet more specific feature, the cartilage conduction unit has a spherical face shape. 
     According to another specific feature, the cartilage conduction vibration source transmits vibration from the inside of a cartilage conduction unit which is situated inside the chassis. In so doing, desired vibration can be propagated to a cartilage conduction unit defining a convex face shape at the chassis surface. Optionally, a space to the inside of the cartilage conduction unit defining a convex face shape can be utilized when situating the cartilage conduction vibration source. 
     According to a more specific feature, a support part is furnished for the purpose of supporting the cartilage conduction vibration source, and transmitting vibration thereof to the inside of a cartilage conduction unit. In so doing, support of the cartilage conduction vibration source and transmission of vibration to the inside of the cartilage conduction unit can be achieved. 
     According to a more specific feature, the support part supports a center part of the cartilage conduction vibration source. According to another more specific feature, the support part supports an end part of the cartilage conduction vibration source. In so doing, effective vibration of the cartilage conduction vibration source and transmission thereof can be achieved. 
     According to another specific feature, the sound output device is configured as a handset of a land-line telephone. In the present invention, the configuration of a cartilage conduction unit defining a convex face shape at the chassis surface is suitable for implementation in a handset of a land-line telephone. 
     According to another specific feature, a stereo audio output device is configured from a pair of sound output devices. In this way, a configuration of a cartilage conduction unit defining a convex face shape at the chassis surface is suited to sound output from a stereo audio output device. 
     According to another feature, there is provided a sound output device having a cartilage conduction unit defining a convex face of conical shape, and a cartilage conduction vibration source for transmitting vibration to a cartilage conduction unit. This conical shape is configured on the presumption that a conical side face will contact the entire circumference of the external auditory meatus opening in satisfactory fashion when the distal end thereof is inserted into the external auditory meatus opening; the depth to which the cone is inserted into the external auditory meatus opening does not have a large influence on cartilage conduction, and a state of constant satisfactory contact of the cartilage conduction unit against the entire circumference of the external auditory meatus can be achieved, regardless of individual differences in the size of the external auditory meatus opening. By employing such a pair of sound output devices which wrap around from the left and right to respectively press against the external auditory meatus opening of each ear, a satisfactory configuration for a stereo audio device can be achieved. 
     According to another feature, there is provided a sound output device having a cartilage conduction unit, and cartilage conduction vibration sources including a plurality of vibration sources having different frequency characteristics, for transmitting vibration to the cartilage conduction unit. By employing a plurality of cartilage conduction vibration sources of different frequency characteristics in complementary fashion in this way, the frequency characteristics of the cartilage conduction unit can be improved. An example of a plurality of vibration sources employed in complementary fashion is a combination of a low-end element and a high-end element. 
     Twenty-Fourth Technical Feature 
     A twenty-fourth technical feature disclosed in the present specification provides a mobile telephone having a right-ear cartilage conduction unit, a left-ear cartilage conduction unit, a linking unit for linking the right-ear cartilage conduction unit and the left-ear cartilage conduction unit, and a cartilage conduction vibration source for transmitting vibration to the right-ear cartilage conduction unit or to the left-ear cartilage conduction unit. This linking unit has various useful functions. 
     According to a specific feature, the linking unit provides rigid joining of the right-ear cartilage conduction unit and the left-ear cartilage conduction unit. In so doing, the relative positional relationship of the right-ear cartilage conduction unit and the left-ear cartilage conduction unit can be stabilized, and the right-ear cartilage conduction unit and the left-ear cartilage conduction unit attached to a mobile telephone in a stable manner. According to a more specific feature, the right-ear cartilage conduction unit, the left-ear cartilage conduction unit, and the linking unit are provided as a practical component integrally formed from a hard material. 
     According to another specific feature, a vibration isolating part is furnished between the right-ear cartilage conduction unit, the left-ear cartilage conduction unit, and the linking unit, and the chassis of the mobile telephone. This vibration isolating part is useful in reducing sound leakage to the surrounding area arising from air conduction occurring when vibration is transmitted to the chassis. According to a more specific feature, the vibration isolating part is formed of an elastomer material. Typically, higher vibration isolating effect is obtained with a vibration isolating part that is softer and thicker, but on the other hand, doing so makes the hold on the right-ear cartilage conduction unit and the left-ear cartilage conduction unit unstable. In accordance with this feature, by providing a rigid joint between the right-ear cartilage conduction unit and the left-ear cartilage conduction unit through the linking unit, the relative positions of both can be maintained, and both can be attached in more stable fashion to the chassis. 
     According to another specific feature, the linking unit transmits vibration between the right-ear cartilage conduction unit and the left-ear cartilage conduction unit. Various useful functions can be obtained by doing so. According to a more specific feature, a cartilage conduction vibration source is joined to either the right-ear cartilage conduction unit or the left-ear cartilage conduction unit, and the linking unit transmits vibration of the cartilage conduction vibration source from the right-ear cartilage conduction unit or the left-ear cartilage conduction unit, whichever has the cartilage conduction vibration source joined thereto, to the unjoined unit. In so doing, useful cartilage conduction can also be obtained from the cartilage conduction unit to which the cartilage conduction vibration source is not joined. 
     According to another more specific feature relating to transmission of vibration between the right-ear cartilage conduction unit and the left-ear cartilage conduction unit by the linking unit, the cartilage conduction vibration source includes a first vibration source and a second vibration source respectively joined to the right-ear cartilage conduction unit and the left-ear cartilage conduction unit, and the linking unit mixes vibration of the first vibration source and the second vibration source. According to another more specific feature, drive signals of mutually inverted waveform are presented to the first vibration source and the second vibration source, and the vibrations thereof are mixed, whereby generation of air-conducted sound through transmission of vibration to the chassis can be reduced. 
     According to another specific feature, the right-ear cartilage conduction unit, the left-ear cartilage conduction unit, and the linking unit are exposed at the mobile telephone surface. In so doing, the cartilage conduction structure can be concentrated at the mobile telephone surface, facilitating the layout of components inside the mobile telephone, as well as obtaining good cartilage conduction through contact from the outside. 
     According to a separate feature, the right-ear cartilage conduction unit and the left-ear cartilage conduction unit are exposed at the mobile telephone surface, while the linking unit is not exposed at the mobile telephone surface. In so doing, good cartilage conduction through contact of the right-ear cartilage conduction unit and the left-ear cartilage conduction unit from the outside can be obtained, and a high degree of freedom in linkage of the two can be achieved. 
     According to another specific feature, the linking unit links the right-ear cartilage conduction unit and the left-ear cartilage conduction unit while bypassing the internal configuration of the mobile telephone. The layout of components inside the mobile telephone can be facilitated thereby. An example of a configuration of the mobile telephone is an in-camera. In this case, the right-ear cartilage conduction unit, the left-ear cartilage conduction unit, and the in-camera, which are all preferably situated in an upper part of the mobile telephone, can be laid out with no interference. 
     According to another specific feature, the right-ear cartilage conduction unit and the left-ear cartilage conduction unit are respectively situated at two corners in an upper part of the mobile telephone. In so doing, contact against the ear cartilage in a natural manner can be achieved regardless of whether the mobile telephone is held in the right hand or held in the left hand, the aforedescribed preferred placement being achievable through the linking unit linking the right-ear cartilage conduction unit and the left-ear cartilage conduction unit. 
     According to another specific feature, there is provided a mobile telephone having a cartilage conduction unit, a cartilage conduction vibration source of elongated shape joined at one end to the cartilage conduction unit, and a weight attached to the other end of the cartilage conduction vibration source. The weight is not supported by any [part] other than this other end, and the inertia afforded by the load thereof is imparted to the other end of the cartilage conduction vibration source. 
     Twenty-Fifth Technical Feature 
     A twenty-fifth technical feature disclosed in the present specification provides an incoming-talk unit for a mobile telephone, having a cartilage conduction unit capable of contacting ear cartilage, an incoming call vibrator, and a short-range communication unit for communicating with the mobile telephone. In so doing, it is possible to be notified of and answer an incoming call while the mobile telephone remains stowed, for example, in a purse or the like; and during videoconferencing or the like, the risk of bothering others, or loss of privacy, due to the other caller&#39;s voice escaping to the surrounding area, can be prevented. According to a specific feature, the unit has a cartilage conduction vibration source for the cartilage conduction unit, and vibration of the cartilage conduction vibration source is employed concomitantly as a vibration source for the incoming call vibrator. 
     According to a specific feature, the incoming-talk unit is further with an outgoing-talk unit. Use as an outgoing-talk/incoming-talk unit is possible thereby. In cases of a compact configuration of such an outgoing-talk/incoming-talk unit, the outgoing-talk unit is preferably a bone conduction microphone. According to a more specific feature, the bone conduction microphone is situated at a location contacting the cheekbone when the cartilage conduction unit is placed in contact against the ear cartilage. 
     According to another specific feature, there is provided a mobile telephone having a cartilage conduction unit capable of contacting ear cartilage, an outgoing-talk unit, a telephone function unit, and a short-range communication unit for communicating with a mobile telephone, capable of independently making calls through the cartilage conduction unit, the outgoing-talk unit, and the telephone function unit, and provided with a cartilage conduction unit and an outgoing-talk unit through communication via the short-range communication unit, and capable of being used as an outgoing-talk/incoming-talk unit for another mobile telephone. In so doing, the various advantages afforded by cartilage conduction can be utilized during in calls made using another, ordinary mobile telephone. In this case, with a view to reasonable use in combination with another mobile telephone, it is preferable for the mobile telephone provided with the aforedescribed features to be configured as an ultra-compact mobile telephone. 
     According to a specific feature, the mobile telephone provided with the aforedescribed features has an incoming call vibrator, the mobile telephone being capable of being used as an incoming call vibrator unit for another mobile telephone, by being operated as an incoming call vibrator via the short-range communication unit. According to a more specific feature, the incoming call vibrator is set up so as to perform different incoming call vibration when there is an incoming call to the telephone function unit, versus when there is an incoming call to the other mobile telephone, transmitted by the short-range communication unit. 
     According to another specific feature, the mobile telephone provided with the aforedescribed features has a display unit, the display unit producing a different display when there is an incoming call to the telephone function unit, versus when there is an incoming call to the other mobile telephone, transmitted by the short-range communication unit. According to another specific feature, the mobile telephone provided with the aforedescribed features has an operating unit, and call answering is initiated through an identical operation performed by the operating unit, when there is an incoming call to the telephone function unit, and when there is an incoming call to the other mobile telephone, transmitted by the short-range communication unit. 
     According to a specific feature, there is provided a mobile telephone that comprises a first section and second section which are separable, the first section being furnished with an outgoing-talk unit, a telephone function unit, and a short-range communication unit for communicating with the second section, and the second section being furnished with a cartilage conduction unit capable of contacting ear cartilage and a short-range communication unit for communicating with the first section, and that functions as an integrated mobile telephone when the first section and the second section are joined, while when the second section is separated from the first section, the second section functions as a remote incoming-talk unit for short-range communication with the first section. In so doing, while the first section is kept stowed, for example, in a purse or the like, it is possible to receive incoming calls through the separated second section, as well as to prevent the risk of bothering others, or loss of privacy, due to the other caller&#39;s voice escaping to the surrounding area, during videoconferencing or the like. 
     According to a specific feature, the second section is furnished with an incoming call vibrator, and when the second section is separated from the first section, the second section functions as a remote incoming call vibrator for the first section. In so doing, it is possible to be notified of and answer incoming calls while keeping the separated second section on the body, for example, in a pocket or the like. According to a specific feature, the unit has a cartilage conduction vibration source for the cartilage conduction unit, and vibration of the cartilage conduction vibration source is employed concomitantly as a vibration source for the incoming call vibrator. 
     According to a specific feature, the first section and the second section are respectively furnished with an operating unit for performing a call answer operation, the operating unit of the second section being disabled when the first section and the second section are joined. According to another specific feature, the first section is furnished with an incoming-talk unit, the incoming-talk unit being disabled when the first section and the second section are joined. According to yet another specific feature, the second section is furnished with an outgoing-talk unit, the outgoing-talk unit being disabled when the first section and the second section are joined. According to a more specific feature, the outgoing-talk unit of the second section is a bone conduction microphone. 
     According to another specific feature, the first section and the second section are respectively furnished with charging means for performing charging of the second section from the first section. In so doing, when the first section is being charged while the first section and the second section are in the joined state, charging of the second section can take place simultaneously as well. According to a more specific feature, the device is configured such that the charging means detects whether or not the first section and the second section are in the joined state, and automatically switches between enabling and disabling functions of the aforedescribed units. 
     According to yet another specific feature, an elastic body is anchored to either the first section or the second section, and the first section or the second section is detachably attached to the other via the elastic body. In so doing, utilizing the separable configuration for the first section and the second section, vibration from the cartilage conduction unit of the second section is not readily propagated to the first section when the two are joined. According to a more specific feature, the elasticity of the elastic body is utilized for detachable attachment of the first section and the second section. 
     Twenty-Sixth Technical Feature 
     A twenty-sixth technical feature disclosed in the present specification provides a mobile telephone having a telephone function unit, a cartilage conduction unit, a cartilage conduction vibration source for vibrating the cartilage conduction unit, a power supply unit for supplying power to the cartilage conduction vibration source, and a power supply control unit for providing a supply of power to the power supply unit when the cartilage conduction unit is in a state able to contact ear cartilage, while halting the supply of power to the power supply unit when the cartilage conduction unit is in a state of non-contact with ear cartilage. Efficient supply of power to the cartilage conduction vibration source is possible thereby. 
     According to a specific feature, the mobile telephone has a power switch, and the state of non-contact of the cartilage conduction unit with ear cartilage refers to a state immediately following turning on of the power switch. According to another specific feature, the mobile telephone has a speaker for outputting sound during videoconferencing, and the state of non-contact of the cartilage conduction unit with ear cartilage refers to the videoconferencing mode state. 
     According to yet another specific feature, the state of non-contact of the cartilage conduction unit with ear cartilage refers to a non-talk state. More specifically, the power supply control unit initiates supply of power to the power supply unit in response to a call initiation signal, and halts the supply of power to the power supply unit in response to a call termination signal. 
     According to a more specific feature, the call initiation signal is an incoming call signal. According to another more specific feature, the call initiation signal is a call request signal. According to another more specific feature, the call termination signal is a call disconnect signal. 
     According to another specific feature, the power supply unit is a voltage booster circuit. According to another specific feature, the cartilage conduction vibration source is a piezoelectric bimorph element. These features are more preferable when combined. 
     According to yet another specific feature, the mobile telephone has an amplifier for providing a call signal to the cartilage conduction vibration source, and the power supply unit supplies power to this amp. According to a more specific feature, a muting circuit is inserted between the cartilage conduction vibration source and the amplifier, and muting is performed by the muting circuit, for predetermined time intervals before and after initiation and termination of supply of power to the power supply unit. More specifically, the power supply control unit initiates muting by the muting circuit, in response to call initiation signals and call termination signals. According to another specific feature, in the aforedescribed configurations, the power supply unit and the power supply control unit are preferably configured as a one-chip integrated circuit. 
     According to another feature, there is provided a mobile telephone having a telephone function unit, a cartilage conduction unit, a cartilage conduction vibration source for vibrating the cartilage conduction unit, a power supply unit for supplying power to the cartilage conduction vibration source, an amplifier for providing a call signal to the cartilage conduction vibration source, and a muting circuit inserted between the cartilage conduction vibration source and the amplifier, for muting for a predetermined time interval, and a muting control unit for initiating muting by the muting circuit, in response to call initiation signals and call termination signals. In so doing, it is possible to control power supply in such a way that popping noises are not produced by the cartilage conduction vibration source at initiation and termination of a call. 
     According to a specific feature, the call initiation signal is an incoming call signal. According to another more specific feature, the call initiation signal is a call request signal. According to another specific feature, the call termination signal is a call disconnect signal. 
     According to another specific feature, the mobile telephone has a power supply control unit that initiates or halts the supply of power to the power supply unit during intervals of muting by the muting circuit. According to another specific feature, in the aforedescribed configurations, the power supply unit, the power supply control unit, and the muting circuit are preferably configured as a one-chip integrated circuit. 
     According to another specific feature, in the aforedescribed configuration the power supply unit is a voltage booster circuit. According to another specific feature, the cartilage conduction vibration source is a piezoelectric bimorph element. These features are more preferable when combined. 
     Twenty-Seventh Technical Feature 
     A twenty-seventh technical feature disclosed in the present specification provides a mobile telephone in which a cartilage conduction unit for touching ear cartilage is furnished to a mobile telephone upper part, and a videoconferencing in-camera is furnished to a mobile telephone lower part. In so doing, the cartilage conduction unit and the videoconferencing in-camera can be situated effortlessly. According to a specific feature, the mobile telephone has a display screen, and the videoconferencing in-camera is furnished to the opposite side from the cartilage conduction unit with the display screen therebetween. 
     According to a more specific feature, the display screen is rectangular, and the videoconferencing in-camera is situated such that a direction perpendicular to the lengthwise sides of the display screen is a vertical direction. In so doing, image capture can take place in a satisfactory manner, while holding the mobile telephone in landscape mode oriented so that the lengthwise sides of the display screen are horizontal. According to another more specific feature, the display screen is rectangular, and the videoconferencing in-camera is furnished to the mobile telephone lower part and biased towards a location positioned to the upper side when the mobile telephone is held oriented so that the lengthwise sides of the display screen are horizontal. In so doing, the face of the user can be captured from above while holding the mobile telephone in landscape mode. 
     According to yet another specific feature, the mobile telephone has orientation detection means for detecting the orientation of the mobile telephone, and image auto-rotation means for rotating an image on the display screen by 90 degrees, on the basis of the orientation detection means, and is moreover furnished with misoperation prevention means for preventing misoperation of the image auto-rotation means on the basis of the videoconferencing in-camera being situated such that a direction perpendicular to the lengthwise sides of the display screen is a vertical direction. In so doing, confusion as to which way an image is pointing can be avoided, while the videoconferencing in-camera is situated such that a direction perpendicular to the lengthwise sides of the display screen is a vertical direction. 
     According to yet another specific feature, the mobile telephone has a piezoelectric bimorph element as the vibration source for the cartilage conduction unit, the piezoelectric bimorph element being adapted to detect the impact of a finger applied to the cartilage conduction unit while the mobile telephone is held in an orientation such that the lengthwise sides of the display screen are horizontal, thereby serving concomitantly as an operation input during videoconferencing. In so doing, the piezoelectric bimorph element can be effectively utilized as a vibration source for the cartilage conduction unit while held in landscape orientation. 
     According to yet another specific feature, the mobile telephone has a piezoelectric bimorph element as the vibration source for the cartilage conduction unit, vibration of the piezoelectric bimorph element being concomitantly employed to provide notification that videoconferencing is in progress, through vibration transmitted to a hand holding the mobile telephone with the lengthwise sides of the display screen horizontal. In so doing, the piezoelectric bimorph element can be effectively utilized as a vibration source for the cartilage conduction unit while held in landscape orientation. 
     According to another specific feature, a light-emitting unit is furnished in proximity to the videoconferencing in-camera, and the line of sight is directed towards the videoconferencing in-camera by emission of light from the light-emitting unit. In so doing, smooth videoconferencing at a natural line of sight can be achieved. 
     According to another feature, there is provided a mobile telephone that has a videoconferencing in-camera, and a main camera for capturing images from the opposite side in relation to the videoconferencing in-camera, and that during videoconferencing transmits an image from the main camera and an image from the videoconferencing in-camera. In so doing, it is possible to transmit images having richer information content. 
     According to another feature, there is provided a mobile telephone that has a videoconferencing in-camera, a main camera for capturing images from the opposite side relative to the videoconferencing in-camera, and a display screen, and that, during videoconferencing, displays on the display screen an image from the main camera and a received image from the videoconferencing in-camera. More accurate image transmission is possible thereby. 
     According to another feature, there is provided a mobile telephone that has a videoconferencing in-camera and a display screen, and that, during videoconferencing, displays on the display screen a received image from the videoconferencing in-camera, and a received image taken from the opposite side in relation to the videoconferencing in-camera. In so doing, it is possible to transmit images having richer information content. 
     According to another feature, there is provided a mobile telephone that has a videoconferencing in-camera, a main camera for capturing images from the opposite side relative to the videoconferencing in-camera, and a display screen, and that, during videoconferencing, displays on the display screen an image from the main camera and a received image taken from the opposite side in relation to the videoconferencing in-camera. In so doing, videoconferencing in which the callers share what they are looking at with one another are possible. 
     Twenty-Eighth Technical Feature 
     A twenty-eighth technical feature disclosed in the present specification provides a cartilage conduction vibration source device having a sound signal input unit for inputting a sound signal, an acoustic signal processing unit for acoustic processing, for purposes of cartilage conduction vibration, of the sound signal input from the sound signal input unit, a power source input unit, a voltage booster circuit unit for boosting an input voltage to the power source input unit, and an amplifier unit supplied with power by the voltage booster circuit unit, for outputting a processed signal processed by the acoustic signal processing unit, to the cartilage conduction vibration source as a drive signal. In so doing, it is possible for the cartilage conduction vibration source to be readily driven in a manner suited to cartilage conduction, by input of an ordinary sound signal and driving by an ordinary power source. 
     According to a specific feature, the sound signal input unit inputs an analog signal from an audio signal output unit, the acoustic signal processing unit and the amplifier unit are constituted by analog circuits, and an analog drive signal is output to the cartilage conduction vibration source. In so doing, the cartilage conduction vibration source can be readily driven in a manner suited to cartilage conduction, on the basis of sound output for an ordinary speaker. 
     According to another specific feature, the sound signal input unit inputs an analog signal from an audio signal output unit, the acoustic signal processing unit is constituted by an AD conversion circuit, a digital acoustic processing circuit, and a DA conversion circuit, and the amp circuit is constituted by an analog circuit which outputs the output of the DA conversion circuit to the cartilage conduction unit as an analog drive signal. In so doing, driving of the cartilage conduction vibration source in a manner suited to cartilage conduction on the basis of sound output for an ordinary speaker can be accomplished at low cost. 
     According to another specific feature, the sound signal input unit inputs a digital signal from the audio signal output unit, the acoustic signal processing unit is constituted by a digital acoustic processing circuit and a DA conversion circuit, and the amp circuit is constituted by an analog circuit which outputs the output of the DA conversion circuit to the cartilage conduction unit as an analog drive signal. In so doing, driving of the cartilage conduction vibration source in a manner suited to cartilage conduction on the basis of ordinary digital sound output can be accomplished at low cost, and with a simple configuration. 
     According to another specific feature, the sound signal input unit inputs a digital signal from the audio signal output unit, the acoustic signal processing unit is constituted by a digital acoustic processing circuit, and the amp circuit is constituted by an analog circuit which outputs the output of the digital acoustic processing circuit to the cartilage conduction unit as a digital drive signal. In so doing, driving of the cartilage conduction vibration source in a manner suited to cartilage conduction on the basis of ordinary digital sound output can be accomplished by a digital circuit only. 
     According to another specific feature, there is provided a cartilage conduction vibration source device having a vibration source module to which a digital drive signal is input, and in which a low pass filter for the digital drive signal and a piezoelectric bimorph element serving as a cartilage conduction vibration source are integrated. The low pass filter is necessary in cases in which the piezoelectric bimorph element is driven by digital drive signals, but merely by using the aforedescribed vibration source module, driving of the cartilage conduction vibration source in a manner suited to cartilage conduction can be accomplished without the burden entailed by having to make preliminary adjustment of the low-pass filter. 
     According to another specific feature, there is provided a cartilage conduction vibration source device having a sound signal output unit for outputting an analog sound signal, an analog sound signal input unit for inputting an analog sound signal, an analog acoustic signal processing unit for acoustic processing, for purposes of cartilage conduction vibration, of a sound signal input from the analog sound signal input unit, an analog amplifier unit for outputting an analog processed signal processed by the analog acoustic signal processing unit, to the cartilage conduction vibration source as a drive signal, and a cartilage conduction vibration source driven by the analog drive signal. In so doing, a suitable cartilage conduction vibration source can be realized through analog circuits. 
     According to another specific feature, there is provided a cartilage conduction vibration source device having a sound signal output unit for outputting an analog sound signal, an analog sound signal input unit for inputting an analog sound signal, an AD conversion circuit for converting a sound signal input from the analog sound signal input unit to a digital signal, a digital acoustic signal processing unit for acoustic processing, for purposes of cartilage conduction vibration, of the output of the AD conversion circuit, a DA conversion circuit for converting a processed signal processed by the digital acoustic signal processing unit to an analog signal, an analog amplifier unit for outputting the output of the DA conversion circuit to the cartilage conduction vibration source as an analog drive signal, and a cartilage conduction vibration source driven by the analog drive signal. In so doing, a suitable cartilage conduction vibration source can be realized at controlled cost, on the basis of analog sound output. 
     According to another specific feature, there is provided a cartilage conduction vibration source device having a sound signal output unit for outputting a digital sound signal, a digital sound signal input unit for inputting a digital sound signal, a digital acoustic signal processing unit for acoustic processing, for purposes of cartilage conduction vibration, of a sound signal input from the digital sound signal input unit, a DA conversion circuit for converting a processed signal processed by the digital acoustic signal processing unit to an analog signal, an analog amplifier unit for outputting the output of the DA conversion circuit to the cartilage conduction vibration source as an analog drive signal, and a cartilage conduction vibration source driven by the analog drive signal. In so doing, a suitable cartilage conduction vibration source can be realized at controlled cost, on the basis of digital sound output. 
     According to another feature, there is provided a cartilage conduction vibration source device having a sound signal output unit for outputting a digital sound signal, a digital sound signal input unit for inputting a digital sound signal, a digital acoustic signal processing unit for acoustic processing, for purposes of cartilage conduction vibration, of a sound signal input from the digital sound signal input unit, a digital amplifier unit for outputting a processed signal processed by the digital acoustic signal processing unit to the cartilage-conduction vibration source as a digital drive signal, a low-pass filter for the digital drive signal, and a cartilage-conduction vibration source driven by a drive signal having passed through the low-pass filter. In so doing, a suitable cartilage conduction vibration source can be realized through digital circuits. In this case, it is possible to integrate the low-pass filter and the cartilage-conduction vibration source and provide these as a vibration source module. 
     Twenty-Ninth Technical Feature 
     A twenty-ninth technical feature disclosed in the present specification provides a mobile telephone having a chassis, a cartilage conduction unit differing in acoustic impedance from the chassis and connected to the chassis, a cartilage-conduction vibration source for transmitting vibration to the cartilage conduction unit, and a load connection unit for connecting a load of an internal structure load to the chassis in proximity to the cartilage conduction unit in the chassis. In so doing, vibration of the chassis is suppressed in proximity to the cartilage conduction unit, which corresponds to an entrance section for vibration transmission, and by avoiding connection of the cartilage conduction unit and the chassis at closely approximating acoustic impedance, it is possible to ensure some degree of freedom in vibration of the cartilage conduction unit and obtain satisfactory cartilage conduction. 
     According to a specific feature, the load connection unit connects the load of the internal structure over a small cross-sectional area to the chassis. In so doing, it is possible for the load connection location to be specifically concentrated in proximity to the cartilage conduction unit, which corresponds to an entrance section for vibration transmission, and it is possible to effectively suppress chassis vibration. 
     According to another specific feature, the cartilage conduction unit and the chassis are connected via a vibration isolating material. In so doing, the effect of avoiding connection of the cartilage conduction unit and the chassis at closely approximating acoustic impedance can be enhanced. According to a more specific feature, a section situated away from the load connection unit is furnished with another load connection unit for connecting a load of an internal structure to the chassis. In so doing, the internal structure is reliably held through a simple configuration. 
     According to another specific feature, the cartilage conduction unit and the chassis are connected directly. In so doing, the number of parts is reduced, and the holding structure for the cartilage conduction unit and the chassis is simple. According to a more specific feature, the cartilage conduction unit is configured from an elastic body of greatly different acoustic impedance from the chassis. 
     According to another specific feature, the internal structure is held to the chassis via a lower vibration isolating material, in a section away from the load connection unit. In so doing, it is possible for the internal structure to be held in reliable fashion without diminishing the effect of specifically concentrating the load connection location to one in proximity to the cartilage conduction unit, which corresponds to an entrance section for vibration transmission. 
     According to another specific feature, the load-connected internal structure is a cell. The cell constitutes a large proportion of the load in a mobile telephone, and is moreover a coherent section, and therefore load connection is preferred. According to a more specific feature, the load connection part is furnished to a holder for holding the cell while avoiding a center section thereof. In so doing, it is possible for the load of the cell to be specifically concentrated in suitable fashion at a location in proximity to the cartilage conduction unit. Furthermore, as the center part of the cell swells with the passage of time during use, in order to avoid this, the configuration of the holder is preferably one that avoids the center section. According to another specific feature, it is possible for the internal structure to be a frame structure than includes a cell holding unit. 
     According to another feature, there is provided a mobile telephone having a chassis, a vibration isolating material connected to the chassis, a cartilage conduction unit connected to the chassis via the vibration isolating material, a cartilage-conduction vibration source for transmitting vibration to the cartilage conduction unit, and a load connection unit for connecting a load of an internal structure to the chassis in proximity to the cartilage conduction unit on the chassis. In so doing, vibration of the chassis can be suppressed, without diminishing good cartilage conduction capability, in the manner described previously. 
     In cases in which the cartilage conduction unit connected to the chassis via the vibration isolating material in the aforedescribed manner, it is possible for the chassis and the cartilage conduction unit to be made of materials of equal acoustic impedance. In so doing, the materials for the mobile telephone are more readily procured, and reduction in cost thereof is possible. 
     According to another feature, there is provided a mobile telephone having an internal structure, a cartilage conduction unit connected to the internal structure, a cartilage-conduction vibration source for transmitting vibration to the cartilage conduction unit, and a chassis connected to the internal structure via the vibration isolating material. In so doing, in the first instance, an internal structure constituting most of the load in the mobile telephone is connected to the cartilage conduction unit thus suppressing transmission of vibration, and moreover, the internal structure is connected, via the vibration isolating material, to the chassis which represents a relatively small proportion of the load, thus suppressing vibration of the chassis, which defines the outer surfaces of the mobile telephone. 
     According to a specific feature, the cartilage conduction unit is connected to the internal structure via the vibration isolating material. According to another specific feature, the cartilage conduction unit is an elastic body. According to these features, good cartilage conduction can be ensured, while suppressing vibration of the chassis. 
     Thirtieth Technical Feature 
     A thirtieth technical feature disclosed in the present specification provides a cartilage-conduction vibration source device having a sound signal input unit for inputting a sound signal, an acoustic signal processing unit for variable processing, for purposes of cartilage conduction, of a sound signal input from the sound signal input unit, a control signal input unit for inputting a control signal for purposes of variable processing in the acoustic signal processing unit, and an amplifier unit for outputting a processed signal processed by the acoustic signal processing unit to a cartilage-conduction vibration source as a drive signal. In so doing, it is possible to drive the cartilage-conduction vibration source for purposes of cartilage conduction, in an appropriate manner according to changes in conditions. 
     According to a specific feature, the acoustic signal processing unit modifies acoustic processing in such a way that the drive signal output to the cartilage-conduction vibration source differs in frequency characteristics, according to whether a sound has arrived via a communication unit or the sound has not arrived via the communication unit. In so doing, the cartilage-conduction vibration source can be driven in a manner that increases the contribution of direct air conduction in cartilage conduction for sounds not arriving via the communication unit, relative to sounds arriving via the communication unit. 
     According to another specific feature, the acoustic signal processing unit modifies acoustic processing in such a way that the drive signal output to the cartilage-conduction vibration source differs in frequency characteristics for a normal individual, versus a person with conductive hearing loss. In so doing, the cartilage-conduction vibration source can be driven in a manner that increases the contribution of cartilage bone conduction in cartilage conduction for a person with conductive hearing loss, relative to a normal individual. 
     According to another specific feature, the acoustic signal processing unit modifies acoustic processing in such a way that the drive signal output to the cartilage-conduction vibration source differs in frequency characteristics in cases in which the external auditory meatus entrance is unoccluded, versus cases in which the entrance is occluded. In so doing, the cartilage-conduction vibration source can be driven in a manner that halts the contribution of direct air conduction in cartilage conduction in cases in which the external auditory meatus entrance is occluded. 
     According to another specific feature, the acoustic signal processing unit has a plurality of acoustic signal processing units, the contributions of the plurality of acoustic signal processing units to the drive signal being modified on the basis of a control signal. In so doing, acoustic processing optimized for each conduction element of cartilage conduction can be respectively devised, and variable acoustic processing controlled through modification of these contributions. 
     According to a specific feature, there is provided a cartilage-conduction vibration source device having a sound signal input unit for inputting a sound signal, a plurality of acoustic signal processing units for processing, for purposes of cartilage conduction, of a sound signal input from the sound signal input unit, and an amplifier unit for outputting a processed signal processed by the plurality of acoustic signal processing units and synthesized, to a cartilage-conduction vibration source as a drive signal. In so doing, acoustic processing can take place through synthesis of acoustic processing optimized for each conduction element of cartilage conduction. 
     According to a specific feature, the plurality of acoustic signal processing units have a first acoustic signal processing unit for carrying out acoustic processing on the basis of the frequency characteristics of cartilage bone conduction from the cartilage-conduction vibration source, and a second acoustic signal processing unit for carrying out acoustic processing on the basis of the frequency characteristics of direct air conduction from the cartilage-conduction vibration source. 
     According to another feature, there is provided a cartilage-conduction vibration source device having a sound signal input unit for inputting a sound signal, an acoustic signal processing unit for processing, for purposes of cartilage conduction, of a sound signal input from the sound signal input unit, and an amplifier unit for outputting a processed signal processed by the acoustic signal processing unit to a cartilage-conduction vibration source as a drive signal, the amplifier unit having a gain adjustment unit for adjusting gain according to input signal level, such that the output level is brought to a predetermined drive signal level for the cartilage-conduction vibration source. In so doing, the capabilities of the cartilage-conduction vibration source can be utilized to maximum effect, to achieve appropriate cartilage conduction. 
     According to a specific feature, there is provided a mobile telephone having the aforedescribed cartilage-conduction vibration source device. According to a more specific feature, the mobile telephone is configured as a mobile device having a combination large-screen display unit/touch screen. According to a more specific feature, a cartilage conduction unit is furnished to a distal end of an extendable and retractable holder joined to the mobile telephone body by a universal joint. 
     According to another feature, there is provided a mobile telephone configured as a mobile device, having a combination large-screen display unit/touch screen furnished to the body thereof, and a sound output unit furnished to a distal end of an extendable and retractable holder joined to the body by a universal joint. In so doing, calling is possible through a simple operation while viewing the large screen. According to a specific feature, the sound output unit is a cartilage conduction unit. 
     Thirty-First Technical Feature 
     A thirty-first technical feature disclosed in the present specification provides a mobile telephone accessory device having an input unit for an external sound signal output by a mobile telephone, a cartilage conduction unit for vibrating on the basis of an external sound signal input from the input unit, and a support unit for supporting the cartilage conduction unit on the mobile telephone. In so doing, an ordinary mobile telephone can be transformed into a cartilage conduction mobile telephone. 
     According to a specific feature, the holder unit is a soft cover sheathing the mobile telephone, the cartilage conduction unit being situated in an upper corner of the soft cover. In so doing, an ordinary mobile telephone can be transformed into a cartilage conduction mobile telephone by being sheathed with the soft cover. 
     According to a more specific feature, the soft cover is configured to be thicker in an upper portion, a cartilage-conduction vibration source being situated in one corner of the upper section, whereby when the mobile telephone is sheathed in the soft cover, the one corner of the thick section where the cartilage-conduction vibration source is situated is supported as a cartilage conduction unit on the mobile telephone. In so doing, the soft cover can be configured as a suitable mobile telephone accessory device. 
     According to a more specific feature, an external earphone plug for insertion of an external output jack of a mobile telephone is situated as an input unit, within the other corner of the thick section of the soft cover. In so doing, there can be configured a mobile telephone accessory device that suitably utilizes the external output of an ordinary mobile telephone. 
     According to a more specific feature, the external earphone plug is situated in the other corner of the thick section where the external output jack of the mobile telephone is insertable prior to sheathing the mobile telephone in the soft cover. In so doing, the mobile telephone can be sheathed by the soft cover, while easily making connection to an external output output from the mobile telephone. 
     According to another more specific feature, the soft cover has a drive unit for driving the cartilage-conduction vibration source, on the basis of a sound signal input from the input unit. In so doing, the cartilage-conduction vibration source can be driven in a suitable manner, on the basis of an external output output from the mobile telephone. According to more specific feature, the soft cover has a power supply unit for supplying power to the drive unit. Suitable cartilage conduction on the basis of an external output output from the mobile telephone can be accomplished thereby. 
     According to another more specific feature, the cartilage-conduction vibration source is an electromagnetic vibrator. In doing, there can be obtained a cartilage-conduction vibration source that is easily assembled into the soft cover. 
     According to another feature, there is provided a mobile telephone having a cartilage conduction vibration unit situated in one upper corner sandwiched between a front face and a rear face, and capable of transmitting vibration from the front face side to the rear face side, and a microphone having symmetrical directionality with respect to the front face side and the rear face side. In so doing, it is possible to make calls in suitable fashion, with the single cartilage conduction vibration unit placed against either the right ear or the left ear. 
     According to a specific feature, the microphone is situated on a side face between the front face and the rear face. According to another specific feature, the microphone is situated on a bottom face between the front face and the rear face. These features respectively facilitate placement of a microphone having symmetrical directionality with respect to the front face side and the rear face side. 
     According to another specific feature, the microphone is furnished to a lower corner which is situated in proximity to the side directly below the upper corner furnished with the cartilage conduction vibration unit. In so doing, the microphone can pick up sound in proximity to mouth, both in the case of placing the single cartilage conduction vibration unit against the right ear, and the case of placing it against the left ear. 
     Thirty-Second Technical Feature 
     A thirty-second technical feature disclosed in the present specification provides a mobile telephone having a sound signal source unit for outputting a sound signal, an equalizer for applying correction to a sound signal output from the sound signal source unit, doing so on the basis of the vibration frequency characteristics of ear cartilage, and a cartilage-conduction vibration source vibrated by the sound signal corrected by the equalizer. In so doing, there can be provided a cartilage conduction mobile telephone incorporating a medical aspect relating to vibration transmission in ear cartilage. 
     According to a specific feature, the equalizer performs correction to boost the gain at the high end within the frequency band at which the cartilage-conduction vibration source is vibrated. This configuration incorporates the medical knowledge that, in the frequency characteristics of vibration transmission in ear cartilage, vibrational acceleration is low at the high end within the frequency band at which the cartilage-conduction vibration source is vibrated. 
     According to a more specific feature, with the external auditory meatus in the occluded state, the equalizer performs correction to boost the gain at the high end within the frequency band at which the cartilage-conduction vibration source is vibrated, to a level higher than the gain when the external auditory meatus is in the unoccluded state. This configuration is based on the medical knowledge that, during cartilage conduction with the external auditory meatus in the unoccluded state, the direct air conduction component is quite large at the high end within the frequency band at which the cartilage-conduction vibration source is vibrated. The configuration moreover takes into account the fact that this direct air conduction component disappears with the external auditory meatus in the occluded state. 
     According to a more specific feature, the mobile telephone has a detection unit for detecting pressing of the mobile telephone against the ear cartilage, and when the output of the detection unit is at or above a predetermined level, the equalizer performs correction to boost the gain at the high end within the frequency band at which the cartilage-conduction vibration source is vibrated, to a level higher than the gain when the external auditory meatus is in the unoccluded state. In so doing, equalization switching can take place in suitable fashion. 
     According to another more specific feature, the mobile telephone has a detection unit for detecting environment noise, and when the output of the detection unit is above a predetermined level, the equalizer performs correction to boost the gain at the high end within the frequency band at which the cartilage-conduction vibration source is vibrated, to a level higher than the gain when the external auditory meatus is in the unoccluded state. This configuration is designed so that equalization switching takes place on the assumption that, when environment noise is above a predetermined level, the user will press the mobile telephone against the ear cartilage to the extent that the external auditory meatus entrance is occluded. 
     According to a more specific feature, the equalizer performs correction to boost the gain at the high end within the frequency band at which the cartilage-conduction vibration source is vibrated, to a level higher than the gain when the external auditory meatus is in the unoccluded state, doing so on the basis of a moving average output of a detection unit. In so doing, equalization switching can takes place in a smooth manner while preventing misoperation. 
     According to a more specific feature, when determined on the basis of the output of the detection unit that the external auditory meatus is obstructed, the equalizer performs correction to rapidly boost the gain at the high end within the frequency band at which the cartilage-conduction vibration source is vibrated, to a level higher than the gain when the external auditory meatus is in the unoccluded state; while halting correction to boost the gain, when output changes of the detection unit have been ascertained multiple times during a decision that the external auditory meatus is unoccluded. This configuration is designed to perform equalization rapidly when the external auditory meatus is occluded, due to the fact that under this condition sounds audible through the external auditory meatus occlusion effect are louder, and changes in sound quality tend to be more noticeable; as well as to prevent excessive equalization switching due to misoperation when the external auditory meatus is unoccluded. 
     According to another specific feature, the mobile telephone has an external sound output unit or a short-range wireless communication unit, and the equalizer performs correction to boost the gain at the high end within the frequency band at which the cartilage-conduction vibration source is vibrated, to a level higher than the gain in sound output from these external output means. This configuration uses equalization appropriate to ordinary air conduction as a benchmark, but incorporates a medical aspect relating to the frequency characteristics of vibration transmission in ear cartilage. 
     According to another specific feature, there is provided a mobile telephone accessory device having an input unit for input of a sound signal output from a mobile telephone, an equalizer for applying correction to a sound signal from the input unit, doing so on the basis of vibration transmission frequency characteristics of ear cartilage, and a cartilage-conduction vibration source vibrated by the sound signal corrected by the equalizer. In so doing, there can be provided an accessory device for a mobile telephone, in which sound output that uses equalization appropriate to ordinary air conduction as a benchmark is input from the mobile telephone, and on the basis thereof, cartilage conduction incorporating a medical aspect relating to vibration transmission in ear cartilage is achieved. 
     According to a specific feature, the equalizer performs correction to boost the gain at the high end within the frequency band at which the cartilage-conduction vibration source is vibrated. Input of sound signals from the mobile telephone to the accessory device may be carried out through a wired connection, or through wireless short-range communication means such as short-range wireless or infrared communication. 
     Thirty-Third Technical Feature 
     A thirty-third technical feature disclosed in the present specification provides a mobile telephone in which elastic bodies are interposed between an upper edge part of the mobile telephone including both upper corners, and other sections of the mobile telephone, and a cartilage-conduction vibration source is furnished inside the upper edge part, such that there is substantially no contact thereof with other sections of the mobile telephone. In so doing, the upper edge of the mobile telephone including both upper corners of the mobile telephone can be vibrated efficiently. 
     According to a specific feature, the cartilage-conduction vibration source is furnished to the inside center of the upper edge part. In so doing, both upper corners of the mobile telephone can be vibrated efficiently, and an upper edge center part can be vibrated efficiently as well. 
     According to another specific feature, the upper edge part is an upper frame of the mobile telephone. In so doing, the upper edge of the mobile telephone including both upper corners of the mobile telephone can be vibrated efficiently, in a manner consistent with the configuration of the mobile telephone. According to a more specific feature, a front face panel of the mobile telephone contacts the upper frame of the mobile telephone. In so doing, suitable cartilage conduction from a front face upper part of the mobile telephone may be obtained in a manner consistent with the configuration of the mobile telephone. 
     According to a more specific feature, the mobile telephone is furnished with two side frames situated with elastic bodies interposed in relation to the upper frame, and contacting the front face panel. In so doing, vibration of the lower front face panel is effectively suppressed. 
     According to a more specific feature, a section of the front face panel contacting the upper frame is at least partially thinner than sections contacting the two side frames. In so doing, vibration of the lower front face panel is effectively suppressed. 
     According to another specific feature, the upper edge part gives rise to cartilage conduction through ear cartilage, when either of the two upper corners is placed in contact with the ear cartilage. In so doing, it is possible take advantage of cartilage conduction when using the mobile telephone. 
     According to another specific feature, the upper edge part gives rise to cartilage conduction through ear cartilage when a center part thereof is placed in contact with the ear cartilage. In so doing, cartilage conduction may be obtained during use as an ordinary mobile telephone. 
     According to another specific feature, the upper edge part is configured to produce predetermined air-conducted sound. In so doing, the air-conducted sound required of an ordinary mobile telephone can be obtained, without furnishing an ordinary speaker. 
     According to another specific feature, the upper edge part is furnished with an external earphone jack which vibrates together with the upper edge part. According to a more specific feature, when detected that an external earphone plug has been inserted into the external earphone jack, vibration of the cartilage-conduction vibration source is prohibited. According to another specific feature, an in-camera is situated in proximity to the upper edge part, and when a mode for using the in-camera is detected, vibration of the cartilage-conduction vibration source is prohibited. According to another specific feature, the upper edge part is furnished with a window through which a power switch can move up or down without contacting the upper edge part. 
     According to another feature, there is provided a mobile telephone having an antenna, and a cartilage-conduction vibration source furnished to the antenna, for concomitantly employing the antenna as a cartilage conduction unit. In so doing, suitable cartilage conduction can be obtained from a front face upper part of the mobile telephone in a manner consistent with the configuration of the mobile telephone. 
     Thirty-Fourth Technical Feature 
     A thirty-fourth technical feature disclosed in the present specification provides a listening device having a cartilage conduction unit for contacting the outside of the base of the ear, and a cartilage-conduction vibration source for propagation of vibration to the cartilage conduction unit. In so doing, the external auditory meatus entrance region is completely free, and so entry of sounds, such as a car horn, into the ear in an emergency situation is unimpeded, nor is there the discomfort associated with inserting an earphone or the like into the external auditory meatus entrance. An external auditory meatus occluding effect can readily be obtained, for example, by covering the ear with the hand in order to enhance the cartilage conduction effect, whereby increased volume and blockage of outside noise can be achieved. 
     According to a specific feature, the listening device provided with the aforedescribed features has an ear-hook unit for linear contact while hooked around the outside of the base of the ear, the inner edge of the ear-hook unit functioning as the cartilage conduction unit. In so doing, suitable holding of the cartilage conduction unit, and satisfactory cartilage conduction, can be achieved. 
     According to a more specific feature, the ear-hook unit is configured of elastic material having acoustic impedance close to that of ear cartilage. In so doing, satisfactory cartilage conduction and a comfortable fit to the outside of the base of the ear can be achieved. 
     According to another specific feature, the cartilage-conduction vibration source is situated in proximity to a section closest to the external auditory meatus entrance, at the outside of the cartilage of the base of ear. In so doing, vibration of the cartilage-conduction vibration source can generate air-conducted sound from the external auditory meatus inner wall through the agency of the cartilage surrounding the external auditory meatus opening, which is then transmitted to the eardrum. 
     According to a more specific feature, a piezoelectric bimorph element is employed as the cartilage-conduction vibration source, adopting a configuration in which one end of the piezoelectric bimorph element is supported by the cartilage conduction unit in proximity to a section closest to the external auditory meatus entrance, at the outside of the cartilage of the base of ear, and the other end side of the piezoelectric bimorph element does not contact the cartilage conduction unit. According to a more specific feature, an electromagnetic vibrator is employed as the cartilage-conduction vibration source, the electromagnetic vibrator being situated in proximity to a section closest to the external auditory meatus entrance, at the outside of the cartilage of the base of ear. 
     According to another more specific feature, the device has a microphone, and a vibration transmission prevention means is devised between the microphone and the cartilage conduction unit contacting the outside of the base of the ear. In so doing, the effects of vibration of the cartilage conduction unit on the microphone can be reduced, in cases in which the listening device of the present invention is applied to an outgoing-talk/incoming-talk device for the purpose of making calls. 
     According to another more specific feature, the vibration transmission prevention means involves configuring the microphone, a power supply unit, and a short-range communication unit for communication with the mobile telephone as separate body from the cartilage conduction unit, the cartilage-conduction vibration source of the cartilage conduction unit and the separate body being connected by flexible cable. According to another more specific feature, a microphone, a power supply unit having a cell, a short-range communication unit for communication with the mobile telephone, and the cartilage conduction unit are configured as an integrated body, the vibration transmission prevention means being realized by situating the cell between the microphone and the cartilage conduction unit in order to suppress vibration due to the load of the cell. 
     According to another feature, there is provided a listening device having a cartilage conduction unit having a passage hole at the center, for insertion into the external auditory meatus entrance, a shutter for opening and closing the passage hole, and a shutter drive unit for driving opening and closing of the shutter by a signal from the outside. In so doing, appropriate external auditory meatus occluding effect can be obtained automatically, or by a manual operation, without the need to push the cartilage conduction unit or block the ear with the hand. 
     According to a specific feature, the listening device has a parameter detection unit, and the shutter drive unit drives opening or closing of the shutter through a signal from the parameter detection unit. The parameter detection unit, for example, detects outside noise, and when the outside noise is above a predetermined level, generates a signal to occlude the shutter, or when the outside noise is below a predetermined level, generates a signal to unocclude the shutter. According to another specific feature, the listening device has a manually-operated unit, and the shutter drive unit drives opening or closing of the shutter through an operation signal generated by operation of the manually-operated unit. 
     According to another feature, there is provided a listening device having an external auditory meatus insertion unit having a passage hole at the center, for insertion into the external auditory meatus entrance, a shutter for opening and closing the passage hole, and a shutter drive unit for driving opening and closing of the shutter by a signal from the outside. In so doing, appropriate external auditory meatus occluding effect can be obtained automatically, or by a manual operation, without the need to push the cartilage conduction unit or block the ear with the hand. 
     Thirty-Fifth Technical Feature 
     A thirty-fifth technical feature disclosed in the present specification provides an outgoing-talk/incoming-talk device having a cartilage conduction unit for contacting the mastoid side of the region of attachment of the auricle, and a contact microphone. In so doing, the outgoing-talk/incoming-talk device can be worn compactly on the head, making it possible, for example, for a helmet or the like to be worn from above. 
     According to a specific feature, the outgoing-talk/incoming-talk device has a cell, the contact microphone being isolated from the cartilage conduction unit by the cell. In so doing, propagation of vibration of the cartilage conduction unit to the contact microphone is suppressed by the cell, making it possible for the contact microphone to be used in suitable fashion. According to another specific feature, the outgoing-talk/incoming-talk device is furnished with canceling means for canceling vibration of the cartilage conduction unit picked up by the contact microphone. In so doing, it possible for the contact microphone to be used in suitable fashion. 
     According to another specific feature, the contact microphone is furnished in proximity to the cartilage conduction unit. In so doing, the outgoing-talk/incoming-talk device can be accommodated compactly in a space behind the ear, making it possible, for example, for a helmet or the like to be worn from above. 
     According to a more specific feature, the contact microphone is situated contacting an area in proximity to the mastoid. According to another more specific feature, the contact microphone is situated contacting an area in proximity to the lower jaw. According to another more specific feature, the contact microphone is situated contacting an area in proximity to the mastoid side of a sternomastoid muscle. With each of these features, suitable voice pickup of can be achieved with the contact microphone in a compact arrangement in proximity to the cartilage conduction unit. 
     According to another specific feature, the device has a wireless communication capable of wireless communication with external equipment. In so doing, the outgoing-talk/incoming-talk device can be given a compact configuration, making it possible, for example, for a helmet or the like to be worn from above. 
     According to another specific feature, cartilage conduction units are furnished so as to respectively contact the mastoid side of the region of attachment of the auricle in each ear. In so doing, stereo listening becomes possible, and the constituent elements of the outgoing-talk/incoming-talk device can be apportioned among both ears, enhancing compactness of the device. 
     According to a more specific feature, the outgoing-talk/incoming-talk device is furnished with a support unit for supporting cartilage conduction units which are furnished for both ears and linked thereto. According to a more specific feature, the contact microphone is furnished to the support unit. According to a specific feature, the contact microphone is situated so as to pick up vibration of the sternomastoid muscle. 
     According to another specific feature, the contact microphone is furnished asymmetrically with respect to cartilage conduction units furnished for both ears, and mutually different canceling is performed on the respective vibrations of the cartilage conduction units picked up by the contact microphone. 
     According to another specific feature, cells are respectively situated in proximity to cartilage conduction units furnished for both ears. In so doing, there can be realized an outgoing-talk/incoming-talk device in which the cells, which occupy considerable volume, are situated in a compact arrangement, making it possible, for example, for a helmet or the like to be worn from above. 
     According to another feature, there is furnished an outgoing-talk/incoming-talk device having a cartilage conduction unit for contacting the mastoid side of the region of attachment of the auricle, and a cover unit for covering an area in proximity to the external auditory meatus entrance. In so doing, sounds obtained through cartilage conduction unit can be heard at higher volume. According to a specific feature, the cover unit is a helmet. 
     INDUSTRIAL APPLICABILITY 
     The various inventions disclosed in the present specification can be applied, for example, to a mobile telephone, a sound output device of a telephone handset or the like, a cartilage-conduction vibration source device for a mobile telephone, a mobile telephone soft cover, a mobile telephone accessory device such as headset or soft cover, an incoming-talk device such as a headset employed with a mobile telephone, or the like, or to an outgoing-talk/incoming-talk device such as a headset employed with a mobile telephone, or the like. 
     LIST OF REFERENCE SIGNS 
     
         
           5881 ,  5881   a ,  5881   b ,  5881   c  Chassis 
           5824 ,  5824   a ,  5824   b ,  5824   c ,  5924 ,  5926  Cartilage conduction unit 
           2525   d ,  2525   e ,  2525   f ,  2525   g ,  2525   h ,  2525   i ,  2525   j ,  2525   k ,  2525   m  Cartilage-conduction vibration source 
           5827 ,  5827   a ,  5827   b  Support unit 
           6024 ,  6124 ,  6224 ,  6324 ,  6424  Right-ear cartilage conduction unit 
           6026 ,  6126 ,  6226 ,  6326 ,  6426  Left-ear cartilage conduction unit 
           6027 ,  6127 ,  6227 ,  6327 ,  6427  Linking unit 
           2525 ,  2525   p ,  2525   q  Cartilage-conduction vibration source 
           6001 ,  6101 ,  6201 ,  6301 ,  6401  Chassis 
           6065 ,  6165 ,  6265 ,  6365 ,  6465  Vibration isolating part 
           2525   q  First vibration source 
           2525   p  Second vibration source 
           36  Drive unit 
           6017 ,  6117 ,  6217  In-camera 
           6025 ,  6125 ,  6225  Weight 
           6024 ,  6124 ,  6224  Cartilage conduction unit 
           6524 ,  6626 ,  6724 ,  6726  Cartilage conduction unit 
           6525  Incoming call vibrator 
           6546  Short-range communication unit 
           2525  Cartilage-conduction vibration source 
           6523  Incoming-talk unit 
           6523  Bone conduction microphone 
           6545  Telephone function unit 
           6505  Display unit 
           6509 ,  6609  Operating unit 
           1601  Other mobile telephone 
           6601   a ,  6701   a  First section 
           6601   b ,  6701   b  Second section 
           223  Outgoing-talk unit 
           45  Telephone function unit 
           1446  Short-range communication unit with second section 
           6546  Short-range communication unit with first section 
           213  Incoming-talk unit 
           1448   b ,  6648   a  Charging means 
           6765  Elastic body 
           5312 ,  5315 ,  5322 ,  5345  Telephone function unit 
           6124 ,  6126  Cartilage conduction unit 
           5325  Cartilage-conduction vibration source 
           5354  Power supply unit 
           5321 ,  5353 ,  5354   a  Power supply control unit 
           5351  Speaker 
           5354  Voltage booster circuit 
           5325  Piezoelectric bimorph element 
           5340  Amp 
           5340   a  Muting circuit 
           5303  One-chip integrated circuit 
           5321  Muting controller 
           5124 ,  5126  Cartilage conduction unit 
           6917  Videoconferencing in-camera 
           6905  Display screen 
           49  Orientation detection means 
           53 ,  239  Screen auto-rotation means 
           239  Misoperation prevention means 
           25  Piezoelectric bimorph element 
           6965  Light-emitting unit 
           6955  Main camera 
           7036 ,  7136 ,  7236  Sound signal input unit 
           7038 ,  7138  Acoustic signal processing unit 
           7054   a  Power input unit 
           7054  Voltage booster circuit unit 
           7040   a ,  7040   b ,  7240   a ,  7240   b ,  7340   a ,  7340   b  Amp unit 
           7013 ,  7313  Cartilage-conduction vibration source 
           7313   a  Low-pass filter 
           7313  Vibration source module 
           7039  Sound signal output unit 
           7401 ,  7401   a ,  7401   b ,  7501 ,  7601 ,  7701   a  Chassis 
           7424 ,  7426  Cartilage conduction unit 
           2525  Cartilage conduction unit 
           7448 ,  7448   a  Internal structure 
           7408  Load-connection part 
           7465  Vibration isolating material 
           7467  Lower vibration isolating material 
           4263   a ,  4263   b  Elastic body (cartilage conduction unit) 
           7448  Cell 
           7406 ,  7416  Holder 
           7748   a  Frame structure 
           7748   b ,  7748   c  Internal structure 
           7701   b ,  701   b  Chassis connected to internal structure 
           7236  Sound signal input unit 
           7538  Acoustic signal processing unit 
           7538   d  Control signal input unit 
           7540  Amp unit 
           7540   b  Gain adjustment unit 
           7013  Piezoelectric bimorph element 
           7438   b  First acoustic signal processing unit 
           7438   c  Second acoustic signal processing unit 
           7601 ,  7701  Mobile device 
           7605 ,  7705  Mobile device with combination touch panel/large screen 
           7681 ,  7781  Support 
           7603 ,  7703  Universal joint 
           7624 ,  7724  Sound output unit 
           7885  Input unit 
           7824  Cartilage conduction unit 
           7863  Support unit 
           7863  Soft cover 
           7824  One corner in thick section 
           7825  Cartilage-conduction vibration source 
           7885  External earphone plug 
           7840  Drive unit 
           7848  Power supply unit 
           7825  Electromagnetic vibrator 
           5124  Cartilage conduction vibration unit 
           7923 ,  8023  Microphone 
           212  Sound signal source unit 
           8138  Equalizer 
           228  Cartilage-conduction vibration source 
           38 ,  242 ,  1588 ,  8124  Detection unit 
           8146  External sound output unit 
           8147  Short-range wireless communication unit 
           1847  Input unit 
           8238  Equalizer 
           1626  Cartilage-conduction vibration source 
           8281  Mobile telephone accessory device 
           8224 ,  8226  Two upper corners 
           8227  Upper edge part 
           228  Cartilage-conduction vibration source 
           8201   f ,  8201   j  Elastic body 
           8227  Upper edge frame 
           8201   a  Front face panel 
           82101   c ,  8201   e  Two side frames 
           8225  Electromagnetic vibrator 
           8227  Antenna 
           8246  External earphone jack 
           8017  In-camera 
           8209  Power switch 
           8382 ,  8482  Cartilage conduction unit 
           8325 ,  8425  Cartilage-conduction vibration source 
           8382 ,  8482  Ear-hook unit 
           8325 ,  8345  Piezoelectric bimorph element 
           8323 ,  8423  Microphone 
           8381   a ,  8485  Vibration transmission prevention means 
           8348 ,  8485  Power supply unit 
           8387 ,  8487  Short-range communication unit 
           8384  Separate body 
           8381   a  Cable 
           8485  Cell 
           8524   a ,  8526   a  Passage hole 
           8524 ,  8526  Cartilage conduction unit 
           8558 ,  8559  Shutter 
           8557   a ,  8557   a  Shutter drive unit 
           8541  Parameter detection unit 
           8509  Manually-operated unit 
           8524 ,  8526  External auditory meatus insertion unit 
           8482 ,  8924   a ,  8924   b  Cartilage conduction unit 
           8623  Contact microphone 
           8485 ,  8985   a ,  8985   b  Cell 
           8636 ,  8640 ,  9140 ,  9140   a  Canceling means 
           8487  Wireless communication unit 
           8981   a ,  9081   a  Support unit 
           9081   b  Cover unit 
           9081   b  Helmet