Patent Publication Number: US-8526657-B2

Title: Headphone set

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
     This application is based on and claims the benefit of priority from the prior Japanese Patent Application No. 2008-333420 filed on Dec. 26, 2008, the entire contents of which is incorporated herein by reference. 
     BACKGROUND OF THE INVENTION 
     The present invention relates to headphone sets, and, especially, so-called an inner-ear type headphone set to be fit in the auricles of user&#39;s ears, equipped with a microphone installed in a headphone housing to pick up ambient sounds. 
     A noise-canceling headphone set having a noise-canceling function, which is now very popular, is one of the known headphone sets equipped with a microphone installed in a headphone housing to pick up ambient sounds. 
     One type of the noise-canceling headphone set is equipped with a microphone installed in a headphone housing to pick up ambient sounds through openings made in the housing. When the ambient sounds are picked up, signals are generated as having the reverse phase of the ambient sounds and combined with audio signals to be listened, and output to user&#39;s ears via speakers. 
     The noise-canceling mechanism cancels the ambient sounds almost completely, that pass through the gap between the headphone housing and user&#39;s ears or the housing itself to reach the user&#39;s ears. With this mechanism, users can enjoy sounds reproduced from audio signals to be listened with almost no effects of the ambient sounds. 
     With increased use of headphone sets for listening music in daily life, not only an overhead type with a headband to be put on the user&#39;s head, but also an inner-ear type to be inserted into the auricles of user&#39;s ears has been very popular now, as noise-canceling headphone sets. 
     The inner-ear type headphone sets include a canal type equipped with a cylindrical sound output tube installed in a headphone housing and attached with a rubber ear piece. The sound output tube is inserted into the canal of a user&#39;s ear so that the ear piece touches the inner wall of the canal. 
     Shown in  FIG. 1  is an appearance of a known inner-ear type noise-canceling headphone set. 
     Installed in a housing  104  are a speaker unit  102  and a microphone  103  aligned along a drive axis CL 101  of the speaker unit  102 . Provided on the back of the housing  104  are sound pick-up holes  104   a  through which ambient sounds are picked up by the microphone  103 . A sound output tube  105  is attached to the housing  104  as protruding in the opposite direction of the microphone  103 . 
     The sound output tube  105  is covered with an ear piece  106 . In use of the headphone set, the ear piece  106  is inserted into the canal of a user&#39;s ear so that the housing  104  is attached inside the auricle of the user&#39;s ear. 
     The known inner-ear type noise-canceling headphone set has several disadvantages as discussed below. 
     The housing  104  is large as indicated by allows L 101  in  FIG. 1 , so that the part of the housing  104  provided with the sound pick-up holes  104   a  protrudes from a user&#39;s ear. This structure allows window noises to be picked up by the microphone  103 , thus posing a difficulty in picking up ambient sounds efficiently. 
     When the window noises are picked up by the microphone  103 , the noises could be amplified and output via a speaker, after undergoing a noise-canceling procedure. 
     The microphone  103  is provided as apart from the ear piece  106 , with the speaker  102  interposed therebetween, as shown in  FIG. 1 . The arrangement has the center of gravity far from the ear piece  106 , thus users could not enjoy fitability to his or her ears and the ear piece  106  could easily be out of position due to user body movements. 
     SUMMARY OF THE INVENTION 
     A purpose of the present invention is to provide an inner-ear type headphone set equipped with a microphone, installed in a headphone housing, to pick up ambient sounds, achieving high fitability to auricles of user&#39;s ears with almost no effects of wind noises. 
     The present invention provides a headphone set comprising: a housing body having a first plane section and a second plane section that faces the first plane section, the first and second plane sections being almost perpendicular to a cross section of a cavum conchae of a user&#39;s ear when the housing body is fit in the cavum conchae, a speaker and a microphone aligned between the first and second plane sections, the speaker being located at the first plane section side, the microphone being located at the second plane section side; a sound output section provided at the first plane section, to give off sounds output by the speaker to an outer space of the housing body; a sound pick-up hole provided at the second plane section, through which the outer space communicates with an inner space of the housing body created between a sound pick-up section of the microphone and the second plane section. 
    
    
     
       BRIEF DESCRIPTION OF DRAWINGS 
         FIG. 1  shows an appearance of a known inner-ear type noise-canceling headphone set; 
         FIG. 2  shows an appearance of a canal-type headphone set having a noise-canceling function, a preferred embodiment according to the present invention; 
         FIG. 3  is a perspective view of an appearance of a left-ear headphone unit when fit in the auricle of the user&#39;s left ear, according to the present invention; 
         FIG. 4  is a perspective view of an appearance of the left-ear headphone unit when viewed from the user&#39;s left-ear auricle side, according to the present invention; 
         FIG. 5  is an illustration of the left-ear headphone unit attached to the user&#39;s left ear, according to the present invention; 
         FIG. 6  is a plan view of the left-ear headphone unit when viewed from the direction indicated by an arrow D 1  in  FIG. 3 , showing a speaker and a microphone both installed in a housing body of the left-ear headphone unit, according to the present invention; 
         FIG. 7  is a perspective sectional view of the left-ear headphone unit taken on line S 1 -S 1  in  FIG. 6 , when viewed from DOWN but obliquely in  FIG. 6 , according to the present invention; 
         FIG. 8  is an enlarged partially perspective sectional view illustrating the microphone and the surrounding components of the left-ear headphone unit, according to the present invention; and 
         FIG. 9  is a perspective view of the left-ear headphone unit when attached to the user&#39;s left ear, according to the present invention. 
     
    
    
     DETAILED DESCRIPTION OF PREFERRED EMBODIMENT 
     A preferred embodiment of a headphone set according to the present invention will be described with reference to the attached drawings. 
     Illustrated in  FIG. 2  is an appearance of a canal-type headphone set  50  having a noise-canceling function, a preferred embodiment according to the present invention. 
     The headphone set  50  is equipped with: a left-ear headphone unit  1 L; a right-ear headphone unit  1 R; cords  2 L and  2   r  pulled out from the units  1 L and  1 R, respectively; a coupler  4  that couples the two cords  2 L and  2   r  into a single connection cord  3 ; an operation unit  5  provided in-between the connection cord  3  and another connection cord  3 ; and a plug  6  provided at the end of the other connection cord  3 . 
     Installed in the headphone units  1 L and  1 R are speaker  7 L and  7 R for sound output, and microphones  12 L and  12 R for picking up ambient sounds, respectively. The speakers  7 L and  7 R, and the microphones  12 L and  12 R have an almost flat cylindrical shape. 
     Installed in the operation unit  5  are a printed circuit board C 2  mounted on which is an electronic circuit C 1  having a noise-canceling function, and a detachable battery BT, such as, a size AAA battery, as a power supply for the electronic circuit C 1 . 
     Provided to the operation unit  5  are a switch  5   a  to switch the noise-canceling function and a button  5   b  to pause the noise-canceling function for listening mainly ambient sounds. 
     When the headphone set  50  is used for, for example, listening music from an external music reproduction apparatus  71 , the plug  6  is connected to an audio output terminal  71   a  of the apparatus  71 . 
     When the noise-canceling function is turned off by the switch  5   a  of the operation unit  5  while the headphone set  50  is being used with the music reproduction apparatus  71 , an audio signal sent from the apparatus  71  via the plug  6  is supplied to the headphone units  1 L and  1 R through the connection cords  3 , the operation unit  5 , and the cords  2 L and  2   r . Thus, sounds based on the audio signal is output from the speakers  7 L and  7 R. 
     On the contrary, when the noise-canceling function is turned on by the switch  5   a , ambient sounds are picked up by the microphones  12 L and  12 R through a pick-up opening  8   g  (not shown in  FIG. 2  and which will be described later). The microphones  12 L and  12 R generate left and right ambient-sound audio signals that carry the ambient sounds. 
     The left and right ambient-sound audio signals are supplied to the electronic circuit C 1  of the operation unit  5 . The electronic circuit C 1  generates left and right canceling signals that have the reverse phase of the left and right ambient-sound audio signals, respectively. Then, the electronic circuit C 1  adds the left and right canceling signals to left and right audio signals supplied from the music reproduction apparatus  71 , respectively, to produce left and right noise-canceling audio signals. 
     The left and right noise-canceling audio signals are supplied to the speakers  7 L and  7 R, respectively. The speakers  7 L and  7 R output sounds based on the left and right noise-canceling audio signals, which cancel or reduce ambient sounds that reach the user&#39;s ears from outside the headphone set  50 . Thus, the user can enjoy the music from the external music reproduction apparatus  71 , without being bothered by ambient noises. 
     Described next is the left-ear headphone unit  1 L of the headphone set  50 . The description is also applied to the right-ear headphone unit  1 R of the headphone set  50  because the units  1 L and  1 R have the symmetrical structures. 
       FIG. 3  shows a perspective view of an appearance of the left-ear headphone unit  1 L when fit in the auricle of the user&#39;s left ear. 
     The arrows with signs FRONT and REAR indicate the directions of the front and rear sides of the user&#39;s head, respectively, when the left-ear headphone unit  1 L is inserted into the auricle of the user&#39;s left ear. The arrows with signs UP and DOWN indicate the user&#39;s parietal and neck sides, respectively, when the unit  1 L is fit in the auricle of the user&#39;s left ear. 
     The left-ear headphone unit  1 L has an egg-shaped housing body  8  having a small-radius section  8   a  having a smaller radius in the direction of REAR and a large-radius section  8   b  having a larger radius in the direction of FRONT when viewed from outside indicated by an arrow D 1 . The unit  1 L is longer in the directions of REAR and FRONT than UP and DOWN. 
     Provided on the housing body  8  in the direction of UP is a protruding member  8   c  that protrudes from the housing body  8  obliquely and upwardly. The protruding member  8   c  has an asymmetrical triangle shape with a summit section  8   c   1  that protrudes most from the housing body  8 , when viewed from D 1 . The direction of the arrow indicated by D 1  is substantially orthogonal to the outer surface of an ornament cap  8   f  which will be described later. 
     The protruding member  8   c  is constituted by the summit section  8   c   1  described above, a first oblique section  8   c   2  having a ridge that is gently joined to the outer curved line of the small-radius section  8   a , and a second oblique section  8   c   3  that joins the summit section  8   c   1  and the large-radius section  8   b  at an angle θ so that the section  8   c   3  steeply rises from the section  8   b.    
     Pulled out upwardly from the second oblique section  8   c   3  is the cord  2 L that is covered with a rubber bushing  9  at an end thereof at the protruding member  8   c  side, for high flexibility. 
     A protrusion  8   t  is formed on the protruding member  8   c  of the left-ear headphone unit  1 L only so that a user can distinguish the left- and right-ear headphone units  1 L and  1 R by the touch. 
     The egg-shaped housing body  8  is constituted by a main housing  8   d , an ornament ring  8   e  fixed to the housing  8   d , and the ornament cap  8   f  (described above) fixed to the ring  8   e  as covering the opening of the ring  8   e . The main housing  8   d  and the ornament ring  8   e  or the ornament cap  8   f  and the ring  8   e  may be formed as one member. 
     The main housing  8   d  is constituted by an inner housing  8   d   1  and an outer housing  8   d   2 . The inner housing  8   d   1  is located at the user&#39;s head (or ear) side when the left-ear headphone unit  1 L is inserted into the auricle of the user&#39;s left ear. 
     The main housing  8   d , the ornament ring  8   e , and the ornament cap  8   f  can be formed by resin injection molding with ABC (Acrylonitrile Butadiene Styrene) resin, PS (Polystyrene) resin, etc. 
     The ornament ring  8   e  is painted according to design, provided with the letter L by silk printing for the left-ear headphone unit  1 L so that a user can distinguish both units  1 L and  1 R. 
     The ornament cap  8   f  is provided with a manufacturer logo and/or a serial number, by silk printing, in a zone SK indicated by a double-dashed dotted line. 
     Provided at a part of the border between the ornament ring  8   e  and cap  8   f  is a sound pick-up opening  8   g  formed in a slit with an arc length L 1 , which will be described later in detail. 
     The left-ear headphone unit  1 L is described further with reference  FIG. 4  that shows a perspective view of an appearance of the unit  1 L when viewed from the user&#39;s left-ear auricle side. The arrows with the signs FRONT, REAR, UP and DOWN indicate the same directions as shown in and defined with respect to  FIG. 3 . 
     In  FIG. 4 , the inner housing  8   d   1  is constituted by a substantially flat egg-like base member  8   dk  and a wall member  8   dh  that stands as surrounding the base member  8   dk.    
     Attached to the base member  8   dk  in the large-radius section  8   b  side, obliquely in the direction the ear canal of the user&#39;s left ear, is a sound output tube  8   h  provided with a rubber ear piece  10  at its end. The ear piece  10  is detachable by a user. 
     Provided on the main housing  8   d  and in the vicinity of the sound output tube  8   h  is a sound-quality adjusting hole  8   i  that communicates a front space of the speaker  7 L (installed in the housing body  8 , as shown in  FIG. 7 ) and the outside. 
     The sounds given off by the speaker  7 L is output through the sound output tube  8   h  to the ear canal of the user&#39;s left ear. 
     Illustrated in  FIG. 5  is that the left-ear headphone unit  1 L is attached to the user&#39;s left ear, with the speaker  7 L and the microphone  12 L, both indicated with dashed lines, installed in the housing body  8 . 
     As illustrated in  FIG. 5 , the left-ear headphone unit  1 L is attached to an auricle E 2  of the user&#39;s left ear so that the entire unit  1 L is fit in a cavum conchae E 1 . In detail, the unit  1 L is fit in the cavum conchae E 1  in such a manner that the large-radius section  8   b  is situated between a tragus E 3  and the cavum conchae E 1  while the small-radius section  8   a  is touched by an inner wall E 4   a  of a helix E 4  that faces the tragus E 3 . The sound pick-up opening  8   g  is provided at a position that is not covered by the helix E 4  when the unit  1 L is attached to the left ear in the manner described above. 
     With respect to  FIG. 5 , one feature of the present invention lies in the arrangement of the speaker  7 L and the microphone  12 L in the housing body  8 . In detail, when the left-ear headphone unit  1 L is fit in the cavum conchae E 1  of the user&#39;s left ear, the speaker  7 L and the microphone  12 L are aligned between a first plane section and a second plane section (both not shown in  FIG. 5 ) of the housing body  8 . The first and second plane sections face each other in the housing body  8 . The first and second plane sections are almost perpendicular to the cross section of the cavum conchae E 1  of the user&#39;s ear when the unit  1 L is fit in the cavum conchae E 1 . 
     Described next with reference to  FIG. 6  are the speaker  7 L and the microphone  12 L both installed in the housing body  8  of the left-ear headphone unit  1 L.  FIG. 6  is a plan view of the unit  1 L when viewed from the direction indicated by the arrow D 1  (almost orthogonal to the zone SK) in  FIG. 3 . The arrows with the signs FRONT, REAR, UP and DOWN indicate the same directions as shown in and defined with respect to  FIG. 3 . 
     As shown in  FIG. 6 , the speaker  7 L and the microphone  12 L are aligned on a longitudinal axis CL 1  of the main housing  8   d , as arranged on the large-radius section  8   b  side and the small-radius section  8   a  side, respectively. Both have an almost flat cylindrical shape in the plan view of  FIG. 6 . 
     In this arrangement, highly efficient inner-space utilization is achieved for the small-radius section  8   a  when the center of the outer curvature of the section  8   a  agrees with the center of the microphone  12 L. Likewise, highly efficient inner-space utilization is achieved for the large-radius section  8   b  when the center of the outer curvature of the section  8   b  agrees with the center of the speaker  7 L. 
     In  FIG. 6 , the center of the outer curvature of the small-radius section  8   a  is a center RC 1  with a radius R 1  from the center RC 1  to the outer-most surface of the section  8   a  in the direction REAR, and the center of the outer curvature of the large-radius section  8   b  is a center RC 2  with a radius R 2  from the center RC 2  to the outer-most surface of the section  8   b  in the direction FRONT. 
       FIG. 6  shows that a center  12 LC of the microphone  12 L and a center  7 LC of the speaker  7 L agree with the curvature centers RC 1  and RC 2 , respectively. 
     The outer surface of the small-radius section  8   a  having the radius R 1  from the center RC 1  is preferably a zone through which the longitudinal axis CL 1  passes. Likewise, the outer surface of the large-radius section  8   b  having the radius R 2  from the center RC 2  is preferably a zone through which the longitudinal axis CL 1  passes. 
     The egg-shaped housing body  8  preferably has a large circumference at the front side of the user&#39;s head and a small circumference at the rear side of the user&#39;s head so that the left-ear headphone unit  1 L is fit well in the cavum conchae E 1  of the auricle E 2 , as shown in  FIG. 5 . 
     It is thus preferable to arrange the speaker  7 L at the FRONT side of the left-ear headphone unit  1 L and the microphone  12 L having a smaller radius than the speaker  7 L at the REAR side of the unit  1 L, as shown in  FIG. 6 , in accordance with the positional relationship between the cavum conchae E 1  and the opening of the ear canal of the user&#39;s left ear. 
     Installation of the microphone  12 L at the rear side of the left-ear headphone unit  1 L is described with reference to  FIGS. 7 to 9 . 
       FIG. 7  is a perspective sectional view of the left-ear headphone unit  1 L taken on line S 1 -S 1  in  FIG. 6 , when viewed from DOWN in  FIG. 6  but obliquely.  FIG. 8  is an enlarged partially perspective sectional view illustrating the microphone  12 L and the surrounding components. 
     Not shown in  FIGS. 7 and 8  for brevity are a pair of lead wires pulled from the rear surface of the speaker  7  that is opposite of a sound output surface  7 L 1  and another pair of lead wires pulled from the rear surface of the microphone  12 L that is opposite of a sound picked-up surface  12 L 1 . The two pairs of lead wires are extended into the cord  2 L. 
     As shown in  FIG. 7 , the speaker  7 L and the microphone  12 L are aligned between the base member  8   dk  of the inner housing  8   d   1  and an outer surface  8   m  (indicated by a chain double-dashed line) of the ornament cap  8   f  and the ornament ring  8   e  so that the speaker  7 L and the microphone  12 L are not overlapped each other in a direction in  FIG. 7  in which a width W lies, which will be discussed later. 
     The speaker  7 L is fixed in a circular rib  61  provided in the inner housing  8   d   1 . The microphone  12 L is attached to a cylindrical holder  13  with an opening at the bottom thereof so that it is tightly fit in the opening. 
     The holder  13  is made of an elastic material, such as, rubber. The holder  13  is provided at the outer housing  8   d   2  side, as being fixed in a circular rib  62  of the housing  8   d   2 . Provided on a top  13   a  of the holder  13  is a circular opening  13   b  exposed through which is at least a part of the sound picked-up surface  12 L 1  of the microphone  12 L. 
     The outer surface of the speaker  7 L is attached tight to the inner circular surface of the circular rib  61  of the inner housing  8   d   1 . The holder  13  is attached tight to the circular rib  62  of the outer housing  8   d   2 . Moreover, the outer surface of the microphone  12 L is attached tight to the inner surface of the holder  13 . This tight structure prevents the sounds from the speaker  7 L from being picked up by the microphone  12 L through the inner housing  8   d   1 . 
     The pick-up opening  8   g  (through which ambient sounds are picked up by the microphone  12 L) is provided as a slot between the ornament ring  8   e  and the ornament cap  8   f , as having the width W in a direction to the user&#39;s head when the headphone unit  1 L is attached to the user&#39;s left ear. 
     The ornament ring  8   e  is provided with a slant section  8   e   1 , as shown in  FIG. 8 , that inclines towards the inner housing  8   d   1  as it becomes closer to the pick-up opening  8   g.    
     With the slant section  8   e   1 , the pick-up opening  8   g  is opened towards the outside of the housing body  8  from inside thereof, in a direction away from the speaker  7 L, with the width W in the direction of the user&#39;s head when the headphone unit  1 L is attached to the user&#39;s left ear, or in the direction parallel to the plane of  FIG. 7 , and with the arc length L 1  ( FIG. 3 ) in a direction perpendicular to the plane of  FIG. 7 . 
     As shown in  FIG. 7 , the left-ear headphone unit  1 L is provided with an inner space SPm that is linked to the sound picked-up surface  12 L 1  of the microphone  12 L. The inner space SPm communicates with an ambient space SPg through the pick-up opening  8   g.    
     In  FIG. 7 , a double-dashed dotted line LN 1  indicates the outer surface of the ornament ring  8   e , that can be extended as linked to an outer edge section  8   f   1  of the ornament cap  8   f  if the pick-up opening  8   g  is not provided. 
     However, since the embodiment of the present invention is provided with the pick-up opening  8   g  and the slant section  8   e   1 , as shown in  FIG. 8 , the outer surface LN 1  of the ornament ring  8   e  is not linked to the outer edge section  8   f   1  of the ornament cap  8   f.    
     Discussed further with respect to  FIG. 9  are the pick-up opening  8   g  having the width W in the direction to the user&#39;s head, when the headphone unit  1 L is attached to the user&#39;s left ear, and the slant section  8   e   1  provided to the ornament ring  8   e.    
       FIG. 9  is a sectional view taken on line S 2 -S 2  in  FIG. 6  when the headphone unit  1 L is attached to the user&#39;s left ear, with an illustration of the auricle E 2  of the user&#39;s left ear. 
     As shown in  FIG. 9 , the slant section  8   e   1  is provided with a slant surface  8   e   1   a  that becomes closer to the inner housing  8   d   1  (a user&#39;s head H) from REAR to FRONT (indicating the same directions as shown in  FIG. 3 ). The slant section  8   e   1  having the slant surface  8   e   1   a  serves well to guide sounds that travel from REAR to the pick-up opening  8   g.    
     The headphone unit  1 L is designed such that the small-radius section  8   a  touches an inner wall E 4   a  of the helix E 4  of the auricle E 2  when attached to the user&#39;s left ear, with the pick-up opening  8   g  located in the vicinity of the wall E 4   a  due to the installation of the microphone  12 L in the section  8   a.    
     The arrangements allow the microphone  12 L to pick up sounds through the pick-up opening  8   g , which are mostly reflected at the inner wall E 4   a  of the helix E 4 , as indicated by arrows SND in  FIG. 9 . 
     When a user hears sounds with his or her ears, the sounds include those reflected at the inner wall E 4   a  of the helix E 4 . Thus, the sounds picked up through the pick-up opening  8   g  are very similar to the sounds which are actually heard by the user with his or her ears. 
     Therefore, the headphone set  50  according to the present invention shows excellent noise-canceling function, by utilizing the sounds picked up through the pick-up opening  8   g.    
     Concerning the noise-canceling function, the pick-up opening  8   g  is positioned in the vicinity of the inner wall E 4   a  of the helix E 4  and close to the user&#39;s head H, as shown in  FIG. 9 , and thus not affected by winds. 
     In detail, the winds that flow from REAR of the user&#39;s head H to FRONT are mostly prevented by the auricle E 2  from reaching the pick-up opening  8   g  that is located behind the auricle E 2  when viewed from REAR. On the other hand, the winds that flow from FRONT of the user&#39;s head H to REAR do not produce rapid flows inside the inner wall E 4   a  of the helix E 4  because the wall E 4   a  functions as a protective wall. Mainly, winds flow along a path AR and thus hardly produce rapid flows in the vicinity of the pick-up opening  8   g.    
     The mechanism described above can restrict wind noises at the pick-up opening  8   g  very well, which serves to improve the quality of sounds reproduced by the headphone set  50 , according to the present invention, with excellent noise-canceling function. 
     As described above, the headphone set  50  is equipped with the speaker  7 L and the microphone  12 L as aligned in the headphone unit  1 L as almost parallel to (or along) the user&#39;s head H, as shown in  FIG. 9 , thus the headphone unit  1 L becomes thinner. 
     The thin headphone unit  1 L does not protrude from the auricle E 2  of the user&#39;s ear so much so that the sound pick-up opening  8   g  provided to the unit  1 L, as described above, can reduce effects of wind noises to the sound reproduction and noise-canceling function. 
     The egg-like headphone unit  1 L is fit well inside the auricle E 2  of the user&#39;s ear due to the location of the small- and large-radius sections  8   a  and  8   b  at the rear and front sides, respectively, of the user&#39;s head, when attached to his or her ear. 
     The pick-up opening  8   g  is provided as having the width W in the direction to the user&#39;s head when the headphone unit  1 L is attached to the user&#39;s left ear, as described with respect to  FIG. 7 . And, the ornament ring  8   e  is provided with the slant section  8   e   1  that inclines towards the inner housing  8   d   1  as it becomes closer to the pick-up opening  8   g , as described with respect to  FIG. 8 , which opening  8   g  is positioned in the vicinity of the inner wall E 4   a  of the helix E 4  when the unit  1 L is attached to the user&#39;s left ear. 
     The arrangements allow the sounds reflected at the helix E 4  of the auricle E 2  of the user&#39;s ear to be guided to the pick-up opening  8   g  so that sounds very similar to those heard through his or her ear can be picked up through the opening  8   g , thus achieving excellent noise canceling function. 
     One requirement in design of the left-ear headphone unit  1 L (and also the right-ear headphone unit  1 R) lies in the distance between a first end and a second end of the housing body  8 , with the large- and small-radius sections  8   b  and  8   a  being provided at the first and second ends, respectively. 
     In detail, the distance between the first and second ends of the housing body  8  is determined so that, when the housing body  8  is fit in the cavum conchae E 1  of the user&#39;s ear, the large-radius section  8   b  is situated between the tragus E 3  of the user&#39;s ear and the cavum conchae E 1  while the small-radius section  8   a  is touched by the inner wall E 4   a  of the helix E 4  of the user&#39;s ear. 
     The pick-up opening  8   g  must be designed with well balanced sizes concerning the arc length L 1  ( FIG. 3 ) and width W ( FIGS. 7 and 8 ), too small sizes causing unstable phase of picked-up sounds while large sizes suffering wind noises. 
     It is further understood by those skilled in the art that the foregoing description is a preferred embodiment of the disclosed apparatus and that various changes and modifications may be made in the present invention without departing from the sprit and scope thereof. 
     For example, the present invention is applicable not only to the canal type but another type in the inner-ear type headphone sets, with a plurality of sound-output holes on the base member  8   dk  ( FIG. 4 ). 
     Moreover, the headphone set according to the present invention may not only be the type having the noise-canceling function but also a microphone-equipped headphone set having a speaker through which sounds are given off to a user&#39; ear and a microphone through which user&#39;s voices are output. 
     According to the present invention, such a microphone-equipped headphone set can also be fit well inside the auricle of a user&#39;s ear, with wind noises being restricted around the microphone, as discussed above. 
     As described above in detail, the present invention achieves high fitability to auricles of user&#39;s ears with almost no effects of wind noises for an inner-ear type headphone set equipped with a microphone, installed in a headphone housing, to pick up ambient sounds.