Patent Publication Number: US-9843874-B2

Title: Equalized hearing aid system

Description:
BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     This application relates to a hearing aid system, and more particularly to a hearing aid system comprising a user configurable equalizer. 
     2. Description of the Prior Art 
     A hearing aid is defined and regulated by the U.S. Food and Drug Administration (FDA) and is an electroacoustic device which is designed to amplify sound for the wearer, usually with the aim of making speech more intelligible, and to correct impaired hearing as measured by audiometry. 
     Most forms of correctable hearing loss exhibit different characteristics according to frequency of the sound. For example, one user may find difficulty in hearing lower frequencies while another user&#39;s difficulty may reside in higher frequencies. Many hearing aids address this problem using frequency compression and/or by shifting inputted frequencies to a higher or lower frequency where they may be more audible to the user of the hearing aid without requiring excessive amplification. Unfortunately, shifting of frequencies often results in an unnatural sound quality. 
     Another difficulty in the use of such hearing aids is that such approaches are frequently fixed at manufacture and are not readily adjustable depending upon local environmental variables or user preferences in different situations. 
     SUMMARY OF THE INVENTION 
     An equalized hearing aid system is proposed that gives the user great flexibility to easily control amplitudes of different audio frequency bands whether from a single source or simultaneously from multiple sources, and may include one speaker or a plurality of speakers providing multiple audio channels. 
     The equalized hearing aid system comprises a microphone, a first variable gain amplifier, a first equalizer, a first mixer, and a first speaker coupled in series forming a first signal path, and a second mixer coupled to the first equalizer within the first signal path. The equalized hearing aid system may further include a Bluetooth module coupled to the first equalizer, and/or a control interface coupled to the first equalizer for controlling the first equalizer. The equalized hearing aid system is configured such that the Bluetooth module may transmit control signals received from another Bluetooth enabled device to the first equalizer for controlling the equalizer, to transmit audio signals received from the microphone to another Bluetooth enabled device, and/or transmit audio signals received from another Bluetooth enabled device to the second mixer. 
     The equalized hearing aid system may further comprise the microphone, a second variable gain amplifier, a second equalizer, a third mixer, and a second speaker coupled in series forming a second signal path with a fourth mixer coupled to the second equalizer within the second signal path. A third equalizer may be coupled to input signal into the first signal path and a fourth equalizer may be coupled to input signal into the second signal path. 
     A preferred equalized hearing aid system may comprise a microphone, a first variable gain amplifier, a first equalizer, a first mixer, and a first speaker coupled in series forming a first audio channel with a second mixer coupled to the first equalizer within the first signal path, the microphone, a second equalizer, a third mixer, and a second speaker coupled in series forming a second audio channel with a fourth mixer coupled to the second equalizer within the second audio channel, a control interface coupled to the first equalizer for controlling the first equalizer and to the second equalizer for controlling the second equalizer, and a Bluetooth module coupled to the first and second equalizers, wherein the Bluetooth module is configured to transmit audio signals received from another Bluetooth enabled device to the first and second equalizers and/or control signals received from the Bluetooth enabled device to the first and/or second equalizers for controlling the first and/or second equalizer respectively. An output of the Bluetooth module is preferably coupled to the second mixer and to the fourth mixer. A third equalizer may be coupled to input signal into the first signal path and a fourth equalizer may be coupled to input signal into the second signal path. 
     An equalized hearing aid system may also comprise a microphone, a first variable gain amplifier, a first equalizer, a first mixer, and a first speaker coupled in series forming a first signal path, a second mixer coupled to the equalizer within the first signal path. The microphone, a second variable gain amplifier, a second equalizer, a third mixer, and a second speaker coupled in series forming a second signal path with a fourth mixer coupled to the second equalizer within the second signal path. A control interface may be coupled to the first equalizer for controlling the first equalizer and to the second equalizer for controlling the second equalizer. A Bluetooth module may be coupled to the first equalizer and to the second equalizer with the Bluetooth module configured to transmit audio signals received from another Bluetooth enabled device to at least one of the first and second signal paths and/or to transmit control signals received from the another Bluetooth enabled device to at least one of the first equalizer for controlling the first equalizer and to the second equalizer for controlling the second equalizer. A third equalizer may be coupled to input signal into the second mixer and a fourth equalizer may be coupled to input signal into the fourth mixer. The Bluetooth module may be further configured to transmit control signals received from another Bluetooth enabled device to at least one of the third equalizer for controlling the third equalizer and to the fourth equalizer for controlling the fourth equalizer. 
     These and other objectives of the present invention will no doubt become obvious to those of ordinary skill in the art after reading the following detailed description of the preferred embodiment that is illustrated in the various figures and drawings. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is a functional block diagram of an equalized hearing aid. 
         FIG. 2  is a functional block diagram of an equalized hearing aid having preferred enhancements to the equalized hearing aid of  FIG. 1 . 
         FIG. 3  is a functional block diagram of an equalized hearing aid having preferred enhancements to the equalized hearing aid of  FIG. 1 . 
         FIG. 4  is a functional block diagram of an equalized hearing aid having preferred enhancements to the equalized hearing aid of  FIG. 2 . 
         FIG. 5  is a functional block diagram of an equalized hearing aid having preferred enhancements to the equalized hearing aid of  FIG. 3 . 
         FIG. 6  is a functional block diagram of an equalized hearing aid having preferred enhancements to the equalized hearing aid of  FIG. 4 . 
         FIG. 7  is a functional block diagram of an equalized hearing aid having preferred enhancements to the equalized hearing aid of  FIG. 5 . 
         FIG. 8  is a functional block diagram of an equalized hearing aid having preferred enhancements to the equalized hearing aid of  FIG. 6 . 
         FIG. 9  is a functional block diagram of an equalized hearing aid that illustrates variations of the equalized hearing aids shown in  FIG. 1 ,  FIG. 3 ,  FIG. 5 , and  FIG. 7 . 
         FIG. 10  is a functional block diagram of an equalized hearing aid that illustrates variations of the equalized hearing aids shown in  FIG. 2 ,  FIG. 4 ,  FIG. 6 , and  FIG. 8 . 
     
    
    
     DETAILED DESCRIPTION 
     An equalizer as used herein is a circuit or equipment used to strengthen or weaken the energy of specific frequency bands by adjusting amplitude of audio signals at particular frequencies. Equalization may be used to eliminate unwanted sounds, make certain sounds more prominent, enhance particular aspects of a tone, combat feedback, adjust the timbre of individual sounds, and to fit individual sounds within or remove individual sounds from the overall frequency spectrum of the mix. 
     Bluetooth as used herein is a wireless technology standard for exchanging data over short distances using short-wavelength UHF radio waves in the industrial, scientific and medical (ISM) band from 2.4 to 2.485 GHz. Bluetooth is managed by the Bluetooth Special Interest Group (SIG), which oversees development of the specification. Herein, the term Bluetooth refers to wireless technology consistent with the Bluetooth specification. Bluetooth® Core Specification 4.2 is included herein by reference. 
     Throughout this application, the term “preferably” means desired but is optional and not required according to design considerations. The term “coupled” means having a direct or an indirect electrical path, again, according to design considerations. Although even a wire inherently changes a signal within it, a direct electrical path between components A and B is intended to mean that no additional component is in the electrical path between components A and B that is used to intentionally delay, store, and/or alter the signal between components A and B. 
       FIG. 1  is a functional block diagram of an equalized hearing aid  100 , i.e., a hearing aid that comprises an equalizer. Equalized hearing aid  100  comprises a microphone  10 , a first variable gain amplifier (VGA)  20 , a first equalizer  30 , a first mixer  72  optionally connected to a first auxiliary input AUX_IN_ 1 , and a first speaker  50  coupled in series to form a signal path. The first mixer  72  is configured to optionally receive Bluetooth signal and/or signal from the first auxiliary input AUX_IN_ 1  for output to the first speaker  50  and/or combine the received signal with signal received from the first equalizer  30  to output the combined signal to the first speaker  50 . The first mixer  72  is also configured to optionally bypass any received Bluetooth signal and/or signal from the first auxiliary input AUX_IN_ 1  and output signal received from the first equalizer  30  to the first speaker  50  according to user preference. The first equalizer  30  preferably includes a driver module for driving electrically coupled speakers, however the driver module may be located in the first mixer  72 , in the first speaker  50 , or another suitable location according to design considerations. 
     To offer a means of control of the first equalizer  30 , equalized hearing aid  100  also preferably includes a control interface  60  coupled or detachably coupled to the first equalizer  30 . The control interface  60  preferably can control the first equalizer  30  parameters and sound volume through the first equalizer  30 . The control interface  60  may include knobs, dials, buttons, or other control hardware and/or software to control the first equalizer  30  to adjust amplitude of the audio signals at particular frequencies via the first equalizer  30 . The control interface  60  preferably can be any user-defined interface, such as an Inter-Integrated Circuit (I 2 C) interface, a Universal Asynchronous Receiver/Transmitter (UART) interface, a Serial Peripheral Interface (SPI), or any other suitable interface. The control interface  60  preferably further includes a connector  61 , such as an audio jack or a Universal Serial Device (USB) port, so that at least a portion of the control interface  60  may be decoupled from the first equalizer when not needed. When the connector  61  is present and the user desires to adjust the equalization levels, at least a portion of the control interface  60  can be coupled to the first equalizer  30  via the connector  61  so that the appropriate command signals may be sent from the at least a portion of the control interface  60  to the first equalizer  30 . 
     In  FIG. 1 , sound is received by the microphone  10 , generating audio signals that may be amplified by the first VGA  20 , then sent to the first equalizer  30  for adjustment of amplitude of the audio signals at particular frequencies according to settings selected by the user via the control interface  60 . After equalization, the audio signals may be transmitted to the first speaker  50  via the first mixer  72 . 
       FIG. 2  is a functional block diagram of an equalized hearing aid  150  having preferred enhancements to the equalized hearing aid  100  of  FIG. 1 . In  FIG. 2 , as in all figures, components having similar functionality share the same identification label number. 
     The equalized hearing aid  150  may include the microphone  10 , the first variable gain amplifier  20 , the first equalizer  30 , the first mixer  72 , and the first speaker  50  coupled in series to form the first signal path, and the interface  60  of  FIG. 1 . In addition to what is shown in  FIG. 1 , the equalized hearing aid  150  also preferably includes the microphone  10 , a second variable gain amplifier  25 , a second equalizer  35 , a second mixer  74  configured to receive input from a second auxiliary input AUX_IN_ 2 , and a second speaker  55  coupled in series to form a second signal path. The second equalizer  35  is also coupled to the interface  60 . 
     In  FIG. 2 , preferably, the second VGA  25  is functionally similar to the VGA  20 , the second equalizer  35  is functionally similar to the first equalizer  30 , and the second mixer  74  is functionally similar to the first mixer  72 . The two speakers  50 ,  55  preferably respectively correspond to a left and a right audio channel. The left and right audio channels may carry a same audio signal or different audio signals according to design or user preferences. The interface  60  is also preferably configured to allow independent control of the parameters for the two equalizers  30 ,  35  and independent control of respective audio volumes of the two speakers  50 ,  55 . 
       FIG. 3  is a functional block diagram of an equalized hearing aid  200  having preferred enhancements to the equalized hearing aid  100  of  FIG. 1 . 
     The equalized hearing aid  200  may include the microphone  10 , the first variable gain amplifier  20 , the first equalizer  30 , the first mixer  72 , and the first speaker  50  coupled in series. The equalized hearing aid  200  also preferably comprises the control interface  60  and also preferably includes the Bluetooth module  80  coupled to the first equalizer and is configured to transmit control signals received from another Bluetooth enabled device  95  to the first equalizer  30  for controlling the first equalizer  30 . 
     The Bluetooth module  80  may be further coupled to a second mixer  70  via connection line  205 . The second mixer  70  is preferably coupled within the first signal path in series between the equalizer  30  and the first mixer  72  and mixes audio signals received by the Bluetooth module  80  with audio signals exiting the first equalizer  30 . Thus, when the Bluetooth module  80  is paired with a suitable Bluetooth enabled device  95 , for example a smartphone, a computer, or tablet, audio signals transmitted by the Bluetooth enabled device  95  are received by the Bluetooth module  80 , transmitted from the Bluetooth module  80  to the second mixer  70 . According to user preference, the audio signals from the Bluetooth module  80  and received by the second mixer  70  may be combined by the second mixer  70  with equalized audio signals originating at the microphone  10  to produce a combined audio signal transmitted to the first mixer  72 . The second mixer  70  may be optionally configured by a user to ignore audio signals audio signals from the Bluetooth module  80  and transmit equalized audio signals originating at the microphone  10  to the first mixer  72  or alternatively configured by a user to ignore equalized audio signals originating at the microphone  10  and transmit the audio signals from the Bluetooth module  80  to the first mixer  72 . 
     The first mixer  72  is also configured to optionally bypass any received Bluetooth signal and/or signal from the first auxiliary input AUX_IN_ 1  and output signal received from the first equalizer  30  to the first speaker  50  according to user preference or to optionally bypass signal received from the first equalizer  30  and output any received Bluetooth signal and/or signal from the first auxiliary input AUX_IN_ 1  to the first speaker  50 . The equalized hearing aid  200  preferably also includes a connection line  201  between the microphone  10  and the Bluetooth module  80  so that audio signals received by the microphone  10  may be transmitted from the Bluetooth module  80  to the Bluetooth enabled device  95  when desired. 
     It is again noted that the first mixer  72  is configured to also receive an auxiliary signal and/or an audio Bluetooth signal and any one or combination of any of the signals received by the first mixer  72  may be output to the first speaker  50  according to design considerations. 
       FIG. 4  is a functional block diagram of an equalized hearing aid  250  having preferred enhancements to the equalized hearing aids  150  and  200 . The equalized hearing aid  250  may include the microphone  10 , the first VGA  20 , the first equalizer  30 , the second mixer  70 , the first mixer  72 , the first speaker  50 , the interface  60 , the second VGA  25 , the second equalizer  35 , the third mixer  74 , the fourth mixer  75 , and the second speaker  55  coupled as shown in  FIG. 4 . The Bluetooth module  80  is coupled to the microphone  10  via connection line  201  so that audio signals from the microphone  10  can be transmitted to the Bluetooth enabled device  95  when desired. The equalized hearing aid  250  preferably also includes a connection line  205  coupling the mixers  70  and  75  to each other and to the Bluetooth module  80 . The Bluetooth module  80  is further configured to transmit control signals received from another Bluetooth enabled device  95  to at least one of the first equalizer  30  for controlling the first equalizer  30  and the second equalizer  35  for controlling the second equalizer  35 . 
       FIG. 5  is a functional block diagram of an equalized hearing aid  300  having preferred enhancements to the equalized hearing aids  100 ,  150 ,  200 , and  250 . 
     The equalized hearing aid  300  may include the microphone  10 , the first VGA  20 , the first equalizer  30 , the second mixer  70 , the first mixer  72 , and the first speaker  50  coupled in series, and also preferably includes the control interface  60 , and the Bluetooth module  80  along with connection line  201  between the Bluetooth module  80  and the output of the microphone  10 , connection line  210  between the Bluetooth module  80  and the first equalizer  30 , and connection line  205  between the Bluetooth module  80  and the second mixer  70 . 
     Thus, when the Bluetooth module  80  is paired with the suitable Bluetooth enabled device  95 , audio signals transmitted by the Bluetooth enabled device  95  are received by the Bluetooth module  80 , transmitted from the Bluetooth module  80  to the second mixer  70 , and combined by the second mixer  70  with equalized audio signals originating at the microphone  10  to produce a combined audio signal transmitted to the first mixer  72 . It is again noted that the first mixer  72  is configured to also receive an auxiliary signal and/or an audio Bluetooth signal and any one or combination of any of the signals received by the first mixer  72  may be output to the first speaker  50  according to design considerations. The Bluetooth module  80  is further configured to transmit control signals received from another Bluetooth enabled device  95  to the first equalizer  30  for controlling the first equalizer  30  via connection line  210 . 
       FIG. 6  is a functional block diagram of an equalized hearing aid  350  having preferred enhancements to the equalized hearing aids  100 ,  150 ,  200 ,  250 , and/or  300 . The equalized hearing aid  350  may include the microphone  10 , the first VGA  20 , the first equalizer  30 , the second mixer  70 , the first mixer  72 , and the first speaker  50  coupled in series. The equalized hearing aid  350  also preferably comprises the microphone  10 , the second VGA  25 , the second equalizer  35 , the fourth mixer  75 , the third mixer  74 , and the second speaker  55  coupled in series, and the control interface  60  and the Bluetooth module  80 . 
     Also preferably included are the connection line  201  coupling the output of the microphone  10  with the Bluetooth module  80  and the second VGA  25 , connection line  210  coupling the Bluetooth module  80  with the first equalizer  30 , connection line  204  coupling the Bluetooth module  80  with the second equalizer  35 , connection line  202  coupling the interface  60  with the first equalizer  30 , connection line  207  coupling the interface  60  with the second equalizer  35 , and connection line  205  coupling the second mixer  70  with the fourth mixer  75 . Because adjustment of the equalization levels of the audio signals received by the equalizers  30  and  35  can be made using the Bluetooth enabled device  95 , the control interface  60  may or may not be included in the equalized hearing aid  350  according to design considerations. 
       FIG. 7  is a function block diagram of an equalized hearing aid  400  that illustrates variations of the equalized hearing aids  100 ,  150 ,  200 ,  250 ,  300 , and  350 . The equalized hearing aid  400  may include the microphone  10 , the first VGA  20 , the first equalizer  30 , the second mixer  70 , the first mixer  72 , and the first speaker  50  coupled in series, and also may comprise the control interface  60 , the Bluetooth module  80 , and the second equalizer  35 . Also preferably included are the connection line  201  coupling the output of the microphone  10  with the Bluetooth module  80 , connection line  210  coupling the Bluetooth module  80  with the first equalizer  30 , connection line  215  coupling the Bluetooth module  80  with the second equalizer  35 , connection line  202  coupling the interface  60  with the first equalizer  30 , connection line  206  coupling the interface  60  with the second equalizer  35 , and connection line  220  coupling the second equalizer  35  to the second mixer  70 . 
     The equalized hearing aid  400  offers the ability to use the interface  60  to adjust parameters controlling the equalizers  30 ,  35 , while parameters controlling the equalizers  30 ,  35  can also be set using the Bluetooth enabled device  95  via the Bluetooth module  80 . Because the different audio signal sources (microphone  10  and Bluetooth enabled device  95 ) may have different audio characteristics, this enables a user to easily adjust the mixed audio signal exiting the second mixer  70  according to the user&#39;s desire. 
       FIG. 8  is a functional block diagram of an equalized hearing aid  450  having preferred enhancements to the equalized hearing aids  100 ,  150 ,  200 ,  250 ,  300 ,  350 , and/or  400 . The equalized hearing aid  450  may include the microphone  10 , the first VGA  20 , the first equalizer  30 , the second mixer  70 , the first mixer  72 , and the first speaker  50  coupled in series to form the first signal path. The equalized hearing aid  450  also preferably comprises the microphone  10 , the second VGA  25 , the second equalizer  35 , the fourth mixer  75 , the third mixer  74 , and the second speaker  55  coupled in series forming the second signal path, and the control interface  60  and the Bluetooth module  80 . New enhancements preferably included in the equalized hearing aid  450  include a third equalizer  90  and a fourth equalizer  95 . 
     Also preferably included are the connection line  201  coupling the output of the microphone  10  with the Bluetooth module  80  and the second VGA  25 , connection line  215  coupling the Bluetooth module  80  with the third equalizer  90  and coupling the Bluetooth module  80  with the fourth equalizer  95 , connection line  210  coupling the Bluetooth module  80  with the first equalizer  30  and coupling the Bluetooth module  80  with the second equalizer  35 , connection line  202  coupling the interface  60  with the first equalizer  30 , connection line  206  coupling the interface  60  with the second equalizer  35 , the third equalizer  90 , and the fourth equalizer  95 , connection line  208  coupling the fourth equalizer  95  with the fourth mixer  75 , and connection line  220  coupling the third equalizer  90  with the second mixer  70 . 
     The structure of the equalized hearing aid  450  permits a user of the Bluetooth enabled device  95  to set control parameters of at least one of the first equalizer  30 , the second equalizer  35 , the third equalizer  90 , and the fourth equalizer  95 , respectively. The interface  60  also permits a user to set control parameters of at least one of the first equalizer  30 , the second equalizer  35 , the third equalizer  90 , and the fourth equalizer  95 , respectively. The parameters for each of the four equalizers  30 ,  35 ,  90 ,  95  may be the same or may differ according to user considerations. This arrangement allows the user to determine a desired and possibly separate balance between audio sources (microphone  10 , Bluetooth enabled device  95 , auxiliary input AUX_IN_ 1 , AUX_IN_ 2 ) for each of the two channels respectively output by the two speakers  50  and  55 . 
     A particular advantage of the equalized hearing aids  150 ,  250 ,  350 , and  450  is the ability to individually control audio characteristics for each of the left and right channels; something that is appreciated by a user where capabilities of one ear may differ from capabilities of the user&#39;s other ear. 
       FIG. 9  is a functional block diagram of an equalized hearing aid  500  that is a possible variation of the equalized hearing aids  200 ,  300 , and/or  400 . A difference in the equalized hearing aid  500  is that the second mixer  70  is serially coupled between the microphone  10  and the first equalizer  30  instead of between the first equalizer  30  and the first mixer  72  according to design considerations. 
     Placement of the second mixer  70  between the microphone  10  and the first equalizer  30  allows audio signals transmitted from the Bluetooth module  80  to be mixed with audio signals originating from the microphone  10  before being transmitted to the first equalizer  30 . 
       FIG. 10  is a functional block diagram of an equalized hearing aid  550  that is a possible variation of the equalized hearing aids  150 ,  250 , and/or  350 . A difference in the equalized hearing aid  550  is that the second mixer  70  is serially coupled between the microphone  10  and the first equalizer  30  and the fourth mixer  75  is serially coupled between the microphone  10  and the second equalizer  35 , again according to design considerations. 
     Placement of the mixers  70  and  75  between the microphone  10  and the first equalizer  30  and the second equalizer  35  respectively allows audio signals originating from the microphone  10  to be mixed with audio signals transmitted from the Bluetooth module  80  before entering the first equalizer  30  and/or the second equalizer  35 . This arrangement provides the ability to individually control audio characteristics for each of the left and right channels when desired. 
     An equalized hearing aid is proposed that includes an equalizer that is adjustable via a control interface  60  and/or a Bluetooth enabled device  95  depending upon local environmental variables or user preferences in different situations. The included Bluetooth module  80  additionally permits sound acquired by the microphone  10  to be transmitted to the Bluetooth enabled device  95  and/or sound or audio signals originating from the Bluetooth enabled device and/or an auxiliary input to reproduce sound with the speaker  50 , or generate individual left and right audio channels to possibly reproduce stereo sound with the speakers  50  and  55 . The disclosed equalized hearing aids permit the user great flexibility to control amplitudes of differing audio frequency bands whether from a single source or simultaneously from multiple sources and is easily user adjustable depending upon local environmental variables or user preferences in different situations through the use of the control interface  60  or the Bluetooth enabled device  95 . 
     Those skilled in the art will readily observe that numerous modifications and alterations of the device and method may be made while retaining the teachings of the invention. Accordingly, the above disclosure should be construed as limited only by the metes and bounds of the appended claims.