Abstract:
The invention is concerned with headphones having left and right supporting members ( 9, 19 ) for a sound transducer ( 11, 14, 20 ). In order to allow for an ameliorated out-of-head localization of acoustic or sound events without noteworthy loss of treble and midrange information in a hearing protecting manner the sound transducer ( 11, 14, 20 ) occupies a position tilted about a horizontal axis in the viewing direction of a headphones user and on a vertical axis intersecting the horizontal axis.

Description:
CROSS REFERENCE TO RELATED APPLICATIONS 
     This application is the U.S. national phase of and claims priority to International Application Number PCT/EP2012/055737 filed on Mar. 29, 2012 which claims priority to German Patent Application Number 202011004575.7 filed Mar. 29, 2011, the contents of each of which are herein incorporated by reference in their entireties. 
     BACKGROUND 
     The invention relates to headphones comprising left and right support members for a sound transducer. 
     Headphones are known in supra-aural or circum-aural design wherein the sound transducer is positioned in a baffle defining the supporting element of the sound transducer, said baffle being located inside left and right, semi-open or closed ear cups that are attached to the ends of a headphone strap and intended to abut the skull of a headphone user via headphone cushions either on his ear (supra-aural), or in an ear enveloping manner (circum-aural). Typically, each baffle carries a single sound transducer at its center, so that sound radiated by it is emitted in the direction substantially normal to the baffle. A disadvantage of this classical central arrangement of the sound transducer is that it promotes the in-head localization of acoustic or sound events produced by the headphones. Surprisingly effective as measure against the in-head localization has been found to not dispose the sound transducer in the center of the baffle but to dispose it offset out of said center downwardly and predominantly forward in viewing direction of a user. Headphones of this kind are disclosed, for example, in the WO/1991/001616. Even with these headphones sound is emitted in the direction substantially normal to the baffle but not directly into the ear canal. Rather, sound strikes the contoured outer ear of the user of the headphones and is reflected from there into the ear canal, recreating a major percentage of the information needed for the out-of-head localization of the “normal” listening situation in the surrounding space without headphones by means of sound generated through headphones for the user thereof. Depending on the individual shape of the outer ear and the auditory experience of a headphones user the irritating in-head localization in headphones use is overcome in this way. A similar effect is attained with headphones, the shells of which mounted on a headband and hence the baffles of the headphones are forwardly offset and tilted around a vertical axis angled towards the ear canal mounted on the headband (AKG 1000). 
     A disadvantage of these known headphones with reduced in-head localization is to be seen in the loss of treble and midrange information due to the fact that the sound is predominantly injected into the ear canal only after reflection on the skull of the headphones user and on his external ear structure, which loss of information turns out to more or less individually depend on the shape of the head and ears of the headphones user in practice resulting in selecting the sound level much too high thereby excessively burdening the ear. 
     SUMMARY OF THE INVENTION 
     An object of the present invention is to provide headphones of the kind defined above which ensure an improved out-of-head localization of acoustic or sound events without significant loss of treble and midrange sound information. 
     This object is achieved by claim  1 . Advantageous developments of the invention are specified in the dependent claims. 
     By means of the disposition of the two sound transducers tilted about two axes according to the invention, resulting in a location of the acoustic or sound center more distant from the ear, sound produced through the sound transducer of the headphones aims to the ear of a headphones user in a directed manner essentially avoiding loss of treble and midrange sound information. Due to the relatively large distance of the sound center from the ear of the headphones user, he does receive a listening experience close to a listening experience of a sound source disposed in the surrounding space in contrast to a listening experience received from a headphones sound transducer disposed in the vicinity of the ear. This benefits the out-of-head localization for listening trough headphones. 
     By means of the displacement of the sound transducer in the horizontal and/or vertical direction in addition to the tilting displacement in accordance with an advantageous development of the invention, especially the in-head localization of acoustic or sound events emitted by headphones can be converted selectively to an out-of-head localization. 
     An optimization of the suppression of in-head localization of acoustic or sound events in favor of off-the-head localization with acoustic or sound events predominantly perceived from the front through the inventive sound-guide is achieved by offsetting the sound center of the sound transducer with respect to the entrance to the ear canal predominantly forward in addition to the tilting of the transducer about two axes. 
     A particularly favorable guidance of sound with minimized distortion of sound is achieved by means of the hollow sound-guide body at one end thereof remote from the ear of a headphones user the sound transducer is located and the other end thereof extends to the vicinity of the ear of the headphones user. The sound-guide body may have different shapes. Particularly preferred is a funnel-shaped, and alternatively, a tubular sound guide body. In case of the funnel-shaped sound-guide body the sound transducer is located at the pointed end of the funnel, which funnel provides on its opposite far open end a large sound outlet, which allows, in addition to sounding the entrance to the ear canal to sound a large part of the outer ear. The tubular sound-guide body in contrast thereto enables to target the sound to a smaller ear region and also to use of a plurality of sound guide members connected to the support member to sound the ear by a plurality of tilted and staggered transducers. 
     Advantageously, each supporting element including the sound-guide body and the sound-guide bodies, respectively are made as a unitary injection molded part of plastic. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       The invention is further illustrated by the drawing: 
         FIG. 1  is a plan view of the side pointing away from the ear of a headphones user of a first embodiment of an element supporting a single sound transducer of the headphones of the present invention comprising a tubular waveguide body receiving the sound transducer; 
         FIG. 2  is a side view of the support element/transducer assembly of  FIG. 1 : 
         FIG. 3  is a plan view of the side pointing away from the ear of a headphones user of a second embodiment of an element supporting two sound transducer of the headphones of the present invention comprising two tubular waveguide bodies receiving each one of the two sound transducers; 
         FIG. 4  is a side view of a support element/transducer assembly of  FIG. 3 , 
         FIG. 5  is a plan view of the side pointing to the ear of a headphones user of a third embodiment of a transducer equipped with a single sound transducer of the headphones of the present invention comprising a funnel-shaped waveguide body receiving the sound transducer 
         FIG. 6  is a sectional view taken along the line A-A of the support element/transducer assembly of  FIG. 5 , 
         FIG. 7  is a sectional view taken along the line A-A of the support element/transducer assembly of  FIG. 5 , and 
         FIG. 8  is a plan view of the sound emitting side of the assembly of  FIG. 5 . 
     
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
     The support element  9  shown in  FIGS. 1 and 2  for a sound transducer  11 , from which in  FIGS. 1 and 2  only the backside with an electromagnetic driver is visible, is forming part of the right ear cup of stereo headphones. The left ear cup is a mirror image of the arrangement shown in  FIG. 1 . The support member  9  comprises a flat plate  10  at the circular edge of which a not shown ear pad is arranged, and a hollow sound-guide body  13  in the form of a tube of circular cross section, the longitudinal axis  12  of which runs tilted or angularly with respect to the disk  10 . The tubular sound-guide body  13  opens with one end into an eccentric ellipse-shaped opening in the disk  10  and supports at the other end the sound transducer  11  of generally circular disk shape, the longitudinal central axis of said transducer being aligned with the longitudinal axis  12  of the sound-guide body  13 . 
     The center Z of the disk supporting member  9  is located at the height of the entrance to the ear canal of the right ear of the headphones user at the position of the sound transducer in conventional headphones. Starting from this central position, the center Z′ of the transducer  11  is shifted or off-set by the distance a along the horizontal axis H in  FIG. 1  through the center Z to the right in the viewing direction of the headphones user, and downwardly by the distance b on the vertical axis V through the center Z. Furthermore, the sound transducer  11  is tilted with respect to the supporting member-plate  9  about a vertical axis parallel to the vertical axis V and a horizontal axis parallel to the horizontal axis H, resulting in a corresponding tilting of the tubular sound-guide body  13 , meaning that the sound transducer ( 11 ,  14 ,  20 ) taking a position tilted about a horizontal axis in the viewing direction of a headphones user and a vertical axis intersecting the horizontal axis and that sound generated from the sound transducer is specifically directed to or aimed at the right ear of the headphones user, that is in case of  FIGS. 1 and 2  to the entrance to the ear canal. Alternatively the tilt and displacement of the sound transducer with respect to the center Z of the disk support member  9  may be chosen so that a larger part of the outer ear is selectively sounded (provided with sound). 
     To keep the dimension of the supporting element  9  in direction of an axis perpendicular to the support member disk  10  due to the longitudinal extension of the tubular sound-guide body  13  at a predetermined tilt and offset position of the transducer  11  minimal, the lower edge of the sound transducer  11  supporting the tube end is disposed nearest possible to the support element disk  10 , as shown in  FIG. 2 . 
     The arrangement of the transducer  11  to the support member  9  as shown in  FIGS. 1 and 2  as well as the mirror-image configuration of this arrangement on the left ear ensures a significant reduction of in-head localization of acoustic or sound events encountered in conventional stereo headphones in favor of an out-of the-head localization or off-head localization, especially in favor of an in-front-of-head localization of acoustic or sound events. Moreover, this kind of sounding or sound provision for the headphones user generates an extremely clean, highly resolved and spatial sound image based on the sound events reproduces by the headphones. 
       FIGS. 3 and 4  show a modification of the support member/sound transducer assembly of  FIGS. 1 and 2  for the sounding of the left ear of a headphones user, wherein in addition to the transducer  11 ′ in the position of mirror image to the sound transducer  11  in  FIGS. 1 and 2  a further sound transducer  14  is arranged eccentrically and tilted on the disk support member  10 ′ of the support member  9 ′. Starting from the center of the disk support member  10 ′ the additional sound transducer  14  is disposed predominantly upwardly and forwardly offset to the sound transducers  11 ′. Like the transducer  11 ′ the additional transducer  14  also is disposed tilted on the supporting member disk  10 ′ such that the sound transducer  14  is directed in or points into sound radiation direction centrically passing through central longitudinal axis  15  as well as the longitudinal center axis  12 ′ of the sound transducer  11 ′ in the direction to the entrance to the auditory canal of the headphones user. 
     In order to allow the additional sound transducer  14  to be arranged tilted as desired and to be connected to the support member disk  10 ′, it sits at the end remote from the support member disk of a tubular sound-guide body  16 , the other end of which is connected flush to an eccentric oval opening in the support member disk  10  in the same manner as the sound-guide body  13 ′. 
     In the embodiment of the support element/transducer arrangement for irradiation sound to or sound the left ear of a headphones user of the present invention headphones shown in  FIGS. 6-7 , a single sound transducer  20  is used in a tilt/offset location or disposition mirror imaged to that one shown in  FIGS. 1 and 2 , said sound transducer being seated at the tip end a funnel-shaped sound-guide body  21  opening with its wide-open end into an oval inner edge  23  of a support member disk  22  of a supporting element  19 . The acoustic or sound center of the sound transducer  20  thus again is disposed downwardly and predominantly forwardly offset with respect to the entrance to the ear canal of a headphones user by the support member disk  22  of the stereo. 
     The support member plate  22  and the funnel-shaped sound-guide  21  constitute a one-piece injection-molded part, preferably an injection molded plastic part, additionally comprising at the outer edge of the support member disk  22  a rearwardly projecting stabilizing collar  24  having a cable guide opening  25  and a circular arc-shaped flange  26  for connection to a not shown headphone bracket.