Patent Publication Number: US-2007098202-A1

Title: Variable output earphone system

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS/INCORPORATION BY REFERENCE  
      This application makes reference to and claims priority to U.S. Provisional Application Ser. No. 60/730,762, filed on Oct. 27, 2005, entitled “Variable Output Earphone System,” which is incorporated herein by reference in its entirety.  
      This application also makes reference to: 
      U.S. Pat. No. 4,170,720, issued on Oct. 9, 1979;     U.S. Pat. No. 5,128,566, issued on Jul. 7, 1992;     U.S. Pat. No. 5,131,046, issued on Jul. 14, 1992; and     U.S. Pat. No. 5,144,675, issued on Sep. 1, 1992.    

      Each of the above stated issued patents is hereby incorporated herein by reference in its entirety. 
    
    
     BACKGROUND OF THE INVENTION  
      Earphones used in connection with the listening or play-back features of audio devices are widely used. For instance, the compact size of portable audio devices, such as variations of the Walkman™, compact disc devices, MP3 players, and iPods™, among others, along with the associated quality in stereo or digital sound produced by such devices, make these devices appealing to a large consumer base.  
      However, one segment of the population that is often unable to enjoy the full benefits of the sound quality obtainable through the use of earphones with such audio devices are individuals who have different hearing levels in each ear. For example a typical audio device has only one volume control. This limitation in volume control provides an individual who has hearing loss in one ear with few options. In such situations, the listener is unable to adjust or set the volume levels for each ear independently of the volume level set for the other ear so that the listener may both comfortably listen to the audio source and enjoy the effects of stereo or digital sound. For example, if the listener has the volume too low, the listener may be unable to hear the audio through one ear. Furthermore, periods of increased sound volume intended to compensate for the hearing loss In one ear may result in uncomfortable listening and/or hearing loss in the other ear.  
      In some prior art earphone devices, the volume level for one speaker channel may be manufactured to have a factory pre-set volume level that is higher or lower than the volume level of the other speaker channel. For example the earphone&#39;s right speaker channel may be pre-set to have a volume level that is 10 dB different than the earphone&#39;s left speaker channel. However, such devices do not allow the listener to control or adjust the difference in volume levels between each earphone speaker so as to suit the listener&#39;s particular hearing impairment.  
      Hearing loss may also affect an individual&#39;s ability to hear certain frequencies. For instance, many individuals with hearing loss may have normal or near normal hearing for low frequencies, but have difficulty hearing high frequencies. Further, some types of audio playback, music, or radio transmissions are essentially considered constant-level. In such situations, a hearing impaired listener may be able to obtain desirable audio levels without a significant negative impact on listening quality by adjusting the speaker balance, and perhaps with the addition of a treble boost. However, such adjustments are not desirable for all types of audio. For example, classical music may have a dynamic range of 30-50 dB. In such situations, more sophisticated electronics may be required to accommodate what is known as recruitment, which is the common experience that low-level sounds may be much more different in loudness between ears than high-intensity sounds for someone with a hearing loss in one ear.  
      Thus, a need exists for earphones that allow the listener to separately adjust the audio volume levels of each earphone speaker channel so as to accommodate for a hearing impairment in one ear or different hearing levels in both ears, and allow the listener to enjoy the effect of stereo or digital sound.  
      Further limitations and disadvantages of conventional and traditional approaches will become apparent to one of skill in the art, through comparison of such systems with the present invention as set forth in the remainder of the present application with reference to the drawings.  
     BRIEF SUMMARY OF THE INVENTION  
      A variable output earphone system, substantially as shown in and/or described in connection with at least one of the figures, as set forth more completely in the claims.  
      Various advantages, aspects and novel features of the present invention, as well as details of an illustrated embodiment thereof, will be more fully understood from the following description and drawings.  
    
    
     BRIEF DESCRIPTION OF SEVERAL VIEWS OF THE DRAWINGS  
       FIG. 1  illustrates an earphone having an in-line volume control positioned along the wiring of the earphone, in accordance with an embodiment of the present invention.  
       FIG. 2  illustrates an electronic circuit that provides a volume control in accordance with an embodiment of the present invention.  
       FIG. 3  illustrates an electronic circuit that provides a volume control and a high frequency boost, in accordance with an embodiment of the present invention.  
       FIG. 4  illustrates an electronic circuit that provides a volume control, a high frequency boost, and a battery powered amplifier, in accordance with an embodiment of the present invention.  
    
    
     DETAILED DESCRIPTION OF THE INVENTION  
      Embodiments of the present invention relate to an earphone that allows for individual adjustment of different audio levels produced out of a first and second speaker to compensate for hearing impairment in one or both ears. The earphone may include a jack plug that is configured for insertion into an audio source that has a first volume control, which may be used to set the audio volume level produced by the first speaker. The earphone may also include a second volume control having an inlet and an outlet, the inlet being operably connected to the jack plug. The second volume control may be configured to adjust the audio volume level produced by the second speaker. The maximum audio volume level of the second volume control may be approximately the same as the audio volume level set by the first volume control. The minimum audio volume of the second volume control may be inaudible.  
      In one embodiment of the present invention, a first volume control located on the audio source, such as a portable radio, compact disc player, tape player: ipod™, stereo, MP3 player, television, or computer, among others, is used to control the audio volume level of a first speaker that is heard by a hearing impaired ear. A second volume control may adjust the audio volume level setting of the first volume control so that volume level produced by the second speaker may be lower than that of the first speaker. The second volume control may be positioned on the earphone, earphone wiring, or connected between the audio source and the earphone. The second volume control may have a range that has a maximum level that is approximately equal to the audio volume level setting of the first volume control, and may be reduced to an at least nearly inaudible level.  
       FIG. 1  illustrates an earphone having an in-line volume control positioned along the wiring of the earphone, in accordance with an embodiment of the present invention. Referring to  FIG. 1 , the earphone  100  may comprise a jack plug  110 , a first speaker  112 , a second speaker  114 , and a first volume control  102  The jack plug  110  may be sized and configured to be inserted into an audio source that has a second volume control. The jack plug  110  may be operably connected to a first speaker  112  so that the first speaker  112  produces sound at a volume level in accordance with the volume setting of the second volume control.  
      The first volume control  102  may be an in-line volume control that is operably connected to the jack plug  110  and the second speaker  114 . The wired connection between the jack plug  110  and the first volume control  102  may allow the first volume control  102  to receive approximately the same level of current and/or voltage that is delivered to the first speaker  112 . Circuitry within the first volume control  102  may then adjust the delivered current and/or voltage so that the volume level produced by the second speaker  114  may be set by the listener to be lower than that produced by the first speaker  112 . The first volume control  102  may comprise a dial  103 , key pad (not pictured), or buttons (not pictured), among others, that allows the listener to adjust the audio volume level produced by the second speaker  114 , for example. The first volume control  102  may also comprise a slide control, or a switch  104 , for adjusting low and high frequency levels (designated by position HF  108 ) and/or selecting frequency responses, such as bass boost for example (designated by position BASS  106 ).  
      While  FIG. 1  illustrates an earphone  100  having a jack plug  110  for insertion into an audio source, in another embodiment of the present invention, the earphone  100  may be wireless. In such an embodiment, a radio frequency transmitter may send or receive audio signals to or from the earphone  100 . The earphone may then comprise circuitry that may allow the volume of each earphone speaker to be individually adjusted so as to accommodate the hearing abilities of each ear.  
       FIG. 2  Illustrates an electronic circuit that provides a volume control, in accordance with an embodiment of the present invention. Referring to  FIG. 2 , the earphone  200  may comprise a jack plug  202 , a left earphone speaker (LES)  204 , a right earphone speaker (RES)  206 , and volume control circuitry (VCC)  216 . The earphone  200  may further comprise a capacitor  212 , and resistors  214 ,  210 , and  208 . The VCC may comprise a variable resistor  218 , resistors  220 ,  222 ,  224 , and a switch  226 . The switch  226  may be adapted to select between positions A and B. In instances when the switch  226  is in position A, the RES  206  may be coupled to the variable resistor  218  via a first signal path comprising resistor  224 . In instances when the switch  226  is in position B, the RES  206  may be coupled to the variable resistor  218  via a second signal path comprising resistors  220  and  222 .  
      As shown, the jack plug  202  may be operably connected to wiring for the earphone speakers. For illustration purposes, the earphone wiring associated with the designation as being “left” (or L) may pass a current and/or voltage onto the first speaker channel that directs sound into the hearing impaired ear, while “right” (or R) designates the wiring that transports the current and/or voltage to the second volume control and then onto the second speaker channel. The left speaker channel wire is shown to pass the current and/or voltage from the audio source to the resistor  208  and then onto the first speaker. In such an arrangement, the volume level produced by the first speaker  204  may correspond to the volume level set by the volume control on the audio source coupled to the earphone  200  via the jack  202 .  
      The right speaker channel wire may deliver the current and/or voltage from the audio source to the VCC  216 . The VCC  216  may be configured to allow the listener to adjust the audio volume produced by the second speaker  206 . In one embodiment of the invention, the VCC  216  may be configured so that the maximum volume produced by the second speaker is at least approximately equal to the audio volume level set by the volume control of the audio source that is coupled via the jack  202 . However, the minimum volume level of the VCC  216  may permit the audio volume produced by the second speaker  206  to be reduced to an at least nearly inaudible level.  
      In an exemplary embodiment of the inventions a listener may place the first speaker  204  into a hearing impaired ear. The listener may then adjust the volume control on the audio source coupled to the earphone  200  via the jack  202  so that the volume level allows the individual to comfortably listen to the audio source through the hearing impaired ear. Then, with the second speaker  206  placed in the individual&#39;s other ear, the VCC  216  may be used to reduce the audio volume produced by the second speaker  206  to a level lower than that produced by the first speaker  204 . By being able to adjust the volume levels of the first speaker  204  and the second speaker  206  individually, the listener may be able to customize the audio levels to suit his/her hearing needs or impairment(s). Such adjustments to the RES  206  may be performed independently of adjustments in the volume to the LES  204   
      In another embodiment of the invention, the listener may further independently adjust the RES  206  by using the switch  226  and selecting between the first signal path or the second signal processing path within the VCC  216 . For example, the listener may obtain a relatively flat perceived frequency response for the RES  206  if the switch  226  is in position A, or a mild bass boost for the LES  206 , if the switch  226  is in position B. Values for the resistors  220 ,  222 , and  224  may be selected accordingly.  
       FIG. 3  illustrates an electronic circuit that provides a volume control and a high frequency boost in accordance with an embodiment of the present invention. Referring to  FIG. 3 , the earphone  300  may comprise a jack plug  302 , a left earphone speaker (LES)  304  a right earphone speaker (RES)  306 , and volume control circuitry (VCC)  314  The earphone  300  may further comprise a resistor  316  and a frequency boost circuit (FBC)  309 .  
      The FBC  309  may comprise a switch  308 , a capacitor  312 , and a resistor  310  The switch  308  may be adapted to select between positions A and B. In instances when the switch  308  is in position A, the LES  304  may be directly coupled to the jack plug  302  via a first signal path  311 , in instances when the switch  308  is in position B, the LES  304  may be coupled to the jack plug  302  via a second signal path  313  comprising the resistor  310  and the capacitor  312 . In this regard, a high frequency boost may be activated within the earphone  300  by switching the switch  308  to position B. When activated via the switch  308 , the high frequency boost may allow for an increase in the sensitivity of high frequency sounds in the LES  304 , while also reducing the sensitivity of the LES  304  to low frequency sounds. For example, in one embodiment of the invention, activation of the high frequency boost may reduce the sensitivity of the LES  304  to low frequencies by approximately 15 dB. In this regard, the boost in high frequency and reduction in low frequency within the earphone system  300  may allow listeners who have a hearing impairment to hear a more natural sound.  
      Even though the VCC  314  is illustrated as comprising only a single variable resistor, the present invention may not be so limited. In another embodiment of the invention, the VCC  314  may be the same as the VCC  216  of  FIG. 2 .  
       FIG. 4  illustrates an electronic circuit that provides a volume control, a high frequency boost, and a battery powered amplifier, in accordance with an embodiment of the present invention. Referring to  FIG. 4 , the earphone  400  may comprise a jack plug  402 , a left earphone speaker (LES)  404 , a right earphone speaker (RES)  406 , and volume control circuitry (VCC)  414 . The earphone  400  may further comprise a resistor  416 , a frequency boost circuit (FBC)  409 , and an amplifier  418 .  
      The FBC  409  may comprise a switch  408 , a capacitor  412 , and a resistor  410 . The switch  408  may be adapted to select between positions A and B. In instances when the switch  408  is in position A, the LES  404  may be directly coupled to the jack plug  402  via a first signal path  411 . In instances when the switch  408  is in position B, the LES  404  may be coupled to the jack plug  402  via a second signal path  413  comprising the resistor  410  and the capacitor  412 . In this regard, a high frequency boost may be activated within the earphone  400  by switching the switch  408  to position B. When activated via the switch  408 , the high frequency boost may allow for an increase in the sensitivity of high frequency sounds in the LES  404 , while also reducing the sensitivity of the LES  404  to low frequency sounds. For example, in one embodiment of the invention, activation of the high frequency boost may reduce the sensitivity of the LES  404  to low frequencies by approximately 15 dB. In this regard, the boost in high frequency and reduction in low frequency within the earphone system  400  may allow listeners who have a hearing impairment to hear a more natural sound.  
      In another embodiment of the invention, the earphone system  400  may utilize the amplifier  418  for increasing the dynamic range of music within the earphone system  400 , thereby allowing for an increase in gain for quiet sounds. The amplifier  418  may comprise, for example, a battery-operated wide-dynamic range compression amplifier, such as a K-AMP. Furthermore, for those with hearing loss in both ears, battery operated amplifiers may be added to both the right and left channel. Even though a single amplifier is added in-line only to the LES  404 , the present invention may not be so limited and another amplifier may be added in-line to the RES  406 . Examples of such battery powered amplifiers are illustrated in U.S. Pat. Nos. 4,170,720, 5,128,566, 5,131,046, and 5,144,675, which are incorporated herein by reference in their entirety.  
      In yet another embodiment of the invention, by using a high-sensitivity earphone such as the Etymotic Research ER6i earphone, the full volume output with most portable players, when using the earphone system  300  in  FIG. 3  or  400  in  FIG. 4 , will be adequate for a user/listener with at least a 70 dB hearing loss. When the hearing loss occurs mostly in the high-frequency region, the introduction of frequency selective circuits, such as the circuits represented by  313  in  FIG. 3  or  413  in  FIG. 4 , will provide adequate output for a 70 dB high-frequency loss and less output where the hearing is closer to normal.  
      Accordingly, aspects of the invention may be realized in hardware, software, firmware or a combination thereof. The invention may be realized in a centralized fashion in at least one computer system or in a distributed fashion where different elements are spread across several interconnected computer systems. Any kind of computer system or other apparatus adapted for carrying out the methods described herein is suited. A typical combination of hardware, software and firmware may be a general-purpose computer system with a computer program that, when being loaded and executed, controls the computer system such that it carries out the methods described herein.  
      One embodiment of the present invention may be implemented as a board level product, as a single chip, application specific integrated circuit (ASIC), or with varying levels integrated on a single chip with other portions of the system as separate components. The degree of integration of the system will primarily be determined by speed and cost considerations. Because of the sophisticated nature of modern processors, it is possible to utilize a commercially available processor, which may be implemented external to an ASIC implementation of the present system. Alternatively, if the processor Is available as an ASIC core or logic block, then the commercially available processor may be implemented as part of an ASIC device with various functions implemented as firmware.  
      The present invention may also be embedded in a computer program product, which comprises all the features enabling the implementation of the methods described herein and which when loaded in a computer system is able to carry out these methods. Computer program in the present context may mean for example any expression, in any language, code or notation, of a set of instructions intended to cause a system having an information processing capability to perform a particular function either directly or after either or both of the following; a) conversion to another language, code or notation; b) reproduction in a different material form. However other meanings of computer program within the understanding of those skilled in the art are also contemplated by the present invention.  
      While the invention has been described with reference to a preferred embodiment, it will be understood by those skilled in the art that various changes may be made and equivalents may be substituted without departing from the scope of the invention. In addition, many modifications may be made to adapt a particular situation or material to the teachings of the invention without departing from its scope. Therefore, it is intended that the invention not be limited to the particular embodiment disclosed, but that the invention will include all embodiments failing within the scope of the appended claims.