(19) United States
`(12) Patent Application Publication (10) Pub. No.: US 2005/0058313 A1
`
`Victorian et al.
`(43) Pub. Date:
`Mar. 17, 2005
`
`US 20050058313A1
`
`(54) EXTERNAL EAR CANAL VOICE
`DETECTION
`
`(76)
`
`Inventors: Thomas A. Victorian, Plymouth, MN
`(US); David A. Preves, Chanhassen,
`MN (US); J. Virgil Bradley, Plymouth,
`MN (US)
`
`Correspondence Address:
`Schwegman, Lundberg, Woessner & Kluth, P.A.
`PO. Box 2938
`
`Minneapolis, MN 55402 (US)
`
`(21) Appl. No.:
`
`10/660,454
`
`(22)
`
`Filed:
`
`Sep. 11, 2003
`
`Publication Classification
`
`Int. Cl.7 ............................... H04R 3/00; H03G 3/20
`(51)
`(52) US. Cl.
`............................................ 381/315; 381/328
`
`ABSTRACT
`(57)
`Ear-level full duplex audio communication systems each
`include one or two ear attachment devices, such as in-the-ear
`(ITE) or behind-the-ear (BTE) devices, that Wirelessly com-
`municates to a remote device such as a computer, a personal
`digital assistant (PDA), a cellular phone, a walkie talkie, or
`a language translator. When used as a hearing aid, such a
`system allows a hearing impaired individual to communicate
`with or through the remote device, such as to talk to another
`person through a cellular phone. When being used as an ear
`piece Wirelessly extended from the remote device, such
`system allows an individual with normal hearing to privately
`communicate with or through the remote device without the
`need of holding the device or wearing any device wired to
`the remote device. Each ear attachment device includes a
`
`voice operated exchange (VOX), housed within the device,
`to preserve energy and hence, maximize the period between
`battery replacement or recharges. The VOX also gates
`various sounds detected by the system to control possible
`echoes and ringing.
`
`[0/8
`
`
`
`[00
`
`Bose Exhibit 1043
`Bose Exhibit 1043
`Bose v. Koss
`Bose v. Koss
`
`

`

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`US 2005/0058313 A1
`
`Mar. 17, 2005
`
`EXTERNAL EAR CANAL VOICE DETECTION
`
`TECHNICAL FIELD
`
`[0001] This document generally relates to ear-level com-
`munication systems and particularly, but not by way of
`limitation,
`to such systems communicating with remote
`devices via full duplex audio.
`BACKGROUND
`
`[0002] Ear-level communication systems are used for
`hearing impaired individuals to use a communication device
`such as a cellular phone or other devices transmitting audio
`signals. They also allow private, hand-free use of such a
`communication device by individuals with normal hearing.
`
`:0003] An ear-level communication system generally
`includes tethered or wireless headsets with a microphone
`300m or a microphone within a cord of the headset to detect
`voice of the person wearing the headsets. An alternative way
`0 detect voice is via bone connection. Examples include a
`‘clam” shell device that couples to the helix and a custom
`earmold with a vibration detector on the outer shell. Voice is
`
`3icked up by detecting bone vibration caused by, and
`epresentative of, the voice of the person wearing the device.
`
`:0004] Bi-directional communication has been achieved
`3y a simplex system including a device in the ear canal that
`30th transmits sound to and picks up sound within the ear
`canal. The device is tethered to a push-to-talk (PTT) system
`such as a walkie talkie. It is not full duplex and therefore
`equires interaction by the user in order to switch from listen
`node to talk mode.
`
`a
`
`_0005] Voice operated exchange (VOX) is used to con-
`serve energy when voice is not being detected or transmit-
`ed. For example, a headset system includes two ear
`Jieces—for full duplex communication with one earpiece
`for transmitting and the other for receiving voice—and uses
`ear canal voice detection to trigger a VOX circuit in a control
`nit wired to the headset. The system requires a headset with
`wo headphones and wires connecting the headphone to a
`control unit such as a device clipped on belt. In another
`example, a full duplex system includes a single headphone
`o transmit and receive voice, again with a VOX circuit in a
`control unit wired to the headphone.
`
`Such ear-level communication systems are likely to
`:0006]
`3e worn by person for log periods of time. Users with
`iearing loss may use such a system on a regular basis, both
`as a conventional hearing aid allowing communication
`directly with a person and as a hearing aid allowing com-
`nunicating through another device. Users with normal hear-
`ing may wear such a system to be communicatively con-
`iected to another person or facility without the need to hold
`a device at any time. For appearance or secrecy reasons,
`ninimal visibility is generally desirable. Wired connection
`Jetween a headset or earpiece and a controller makes the
`system easily visible and is cumbersome to users who need
`0 communicate while being physically active.
`
`_0007] Thus, there is a need for an ear-level communica-
`ion system that is not easily visible. A need related to
`niniaturization is that the longevity of the system between
`3attery replacements or recharges.
`SUMMARY
`
`:0008] Ear-level full duplex audio communication sys-
`ems each include one or two ear attachment devices, such
`
`as in-the-ear (ITE) or behind-the-ear (BTE) devices, that
`wirelessly communicates to a remote device. Such a system
`allows a hearing impaired individual to communicate with
`or through the remote device, such as to talk to another
`person through a cellular phone. Such a system also func-
`tions as an ear piece wirelessly extended from the remote
`device that allows an individual to privately communicate
`with or through the remote device without
`the need of
`holding the device.
`
`In one embodiment, a system includes an earmold
`[0009]
`configured for use as an ITE device. The earmold houses a
`microphone for use in an ear canal, a processor, and a
`wireless transmitter. The microphone receives an occluded
`sound from about the ear canal. The processor processes the
`occluded sound. The wireless transmitter receives the pro-
`cessed occluded sound from the processor and transmits a
`wireless signal representing the occluded sound.
`
`In one embodiment, a system includes an ITE
`[0010]
`module and a BTE module attached to the ITE module. The
`
`ITE module includes a microphone for use in an ear canal.
`The microphone receives an occluded sound from about the
`ear canal. The BTE module includes a processor and a
`wireless transmitter. The processor processes the occluded
`sound. The wireless transmitter receives the processed
`occluded sound from the processor and transmits a wireless
`signal representing the occluded sound.
`
`In one embodiment, a system includes a first ear-
`[0011]
`level device and a second ear-level device for use in two
`
`opposite ears. The first ear-level device includes a micro-
`phone, a first processor, and a wireless transmitter. The
`microphone is for use in one ear canal to receive an occluded
`sound from about that ear canal. The first processor converts
`the occluded sound to an electrical signal. The wireless
`transmitter receives the electrical signal and transmits an
`outgoing wireless signal representing the occluded sound.
`The second ear-level device includes a wireless receiver, a
`second processor, and a speaker. The wireless receiver
`receives an incoming wireless signal representing a remote
`sound. The second processor converts the incoming wireless
`signal to the remote sound. The speaker is for use in the
`opposite ear canal to transmit the remote sound to that ear
`canal.
`
`In one embodiment, an occluded sound is detected
`[0012]
`using a microphone placed in an ear canal. An incoming
`radio signal representing a remote sound from a remote
`device is also detected. A voice operated exchange (VOX)
`housed within an ear-level communication device is started
`
`when at least one of the occluded sound and the incoming
`radio signal is detected if the VOX is not already on. The
`ear-level communication device includes one of an ITE
`device and a BTE device. When the occluded sound is
`
`detected while the incoming radio signal is not detected, the
`occluded sound is gated on, and remote sound is gated off.
`When the incoming radio signal
`is detected while the
`occluded sound is not detected, the remote sound is gated on,
`and the occluded sound is gated off.
`
`[0013] This Summary is an overview of some of the
`teachings of the present application and not intended to be
`an exclusive or exhaustive treatment of the present subject
`matter. Further details about the present subject matter are
`found in the detailed description and appended claims. Other
`aspects of the invention will be apparent to persons skilled
`
`

`

`US 2005/0058313 A1
`
`Mar. 17, 2005
`
`in the art upon reading and understanding the following
`detailed description and Viewing the drawings that form a
`part thereof, each of which are not to be taken in a limiting
`sense. The scope of the present invention is defined by the
`appended claims and their equivalents.
`
`BRIEF DESCRIPTION OF THE DRAWINGS
`
`In the drawings, which are not necessarily drawn to
`[0014]
`scale, like numerals describe similar components throughout
`the several views. The drawings illustrate generally, by way
`of example, but not by way of limitation, various embodi-
`ments discussed in the present document.
`
`[0015] FIG. 1 is an illustration of an embodiment of an
`ear-level communication system and portions of an envi-
`ronment in which it is used. This ear-level communication
`
`system uses a single ear-level device.
`
`[0016] FIG. 2 is an illustration of an embodiment of
`another ear-level communication system and portions of an
`environment in which it is used. This ear-level communi-
`
`cation system uses a pair of ear-level devices.
`
`:0017] FIG. 3A is an illustration of one exemplary exte-
`ior configuration of an in-the-ear (ITE) device used as the
`single ear-level device of FIG. 1 or one of the pair of
`ear-level devices of FIG. 2.
`
`:0018] FIG. 3B is an illustration of one exemplary exte-
`ior configuration of an in-the-canal (ITC) device used as the
`single ear-level device of FIG. 1 or one of the pair of
`ear-level devices of FIG. 2.
`
`
`
`:0019] FIG. 3C is an illustration of one exemplary exte-
`ior configuration of a completely-in-the-canal (CIC) device
`sed as the single ear-level device of FIG. 1 or one of the
`3air of ear-level devices of FIG. 2.
`
`:0020] FIG. 4A is a block diagram showing one embodi-
`nent of the circuit of ear-level device shown in FIGS. 3A,
`3B, or 3C used as the single ear-level device of FIG. 1.
`
`:0021] FIG. 4B is a block diagram showing one embodi-
`nent of portions of a voice operated exchange (VOX) circuit
`included in the single ear-level device of FIG. 1.
`
`a block diagram showing another
`:0022] FIG. 5 is
`embodiment of the circuit of ear-level device shown in
`
`FIGS. 3A, 3B, or 3C used as the pair of ear-level devices of
`FIG. 1B.
`
`[0023] FIG. 6 is an illustration of one exemplary exterior
`configuration of an ear-level device including a behind-the-
`ear (BTE) device used as the single ear-level device of FIG.
`1 or one of the pair of ear-level devices of FIG. 2.
`
`[0024] FIG. 7 is a block diagram showing one embodi-
`ment of the circuit of the ear-level device shown in FIG. 6
`
`used as the single ear-level device of FIG. 1.
`
`a block diagram showing another
`[0025] FIG. 8 is
`embodiment of the circuit of ear-level device shown in FIG.
`
`6 used as the pair of ear-level devices of FIG. 2.
`
`[0026] FIG. 9 is a flow chart illustrating an embodiment
`of a method for audio communication between the single
`ear-level device or the pair of ear-level devices and a remote
`device.
`
`
`
`[0027] FIG. 10 is a flow chart illustrating another embodi-
`ment of the method for audio communica ion between the
`
`single ear-level device and a remote device.
`
`DETAILED DESCRIPTIOV
`
`In the following detailed description, reference is
`[0028]
`made to the accompanying drawings which form a part
`hereof, and in which is shown by way of ill stration specific
`embodiments in which the invention may be practiced.
`These embodiments are described in su icient detail
`to
`
`
`
`enable those skilled in the art to practice the invention, and
`it is to be understood that the embodimen s may be com-
`bined, or that other embodiments may be utilized and that
`structural,
`logical and electrical changes may be made
`without departing from the spirit and scope of the present
`invention. The following detailed description provides
`examples, and the scope of the present invention is defined
`by the appended claims and their equivalents.
`
`It should be noted that references to “an”, “one”, or
`[0029]
`“various” embodiments in this disclosure are not necessarily
`to the same embodiment, and such references contemplate
`more than one embodiment.
`
`[0030] This document discusses, among other things, ear-
`level full duplex audio communication systems for commu-
`nicating with remote devices. These systems each include
`one or two ear-level devices each worn in or about an ear,
`such as in-the-ear (ITE) or behind-the-ear (BTE) devices,
`wirelessly coupled to a remote device such as a computer, a
`personal digital assistant (PDA), a cellular phone, a walkie
`talkie, or a language translator. When used as a hearing aid,
`such a system allows a hearing impaired individual
`to
`communicate with or through the remote device, such as to
`talk to another person through a cellular phone. When being
`used as an ear piece wirelessly extended from the remote
`device, such system allows an individual with normal hear-
`ing to privately communicate with or through the remote
`device without the need of holding the device or wearing any
`device wired to the remote device.
`
`In this document, “voice” includes to the sound of
`[0031]
`speech made by a person, and sound generally includes an
`audible signal that includes voice and other signals that can
`be heard and/or detected by an audio detector. Unless
`particularly indicated, for example, when voice is distin-
`guished from sound by speech recognition, “voice” and
`“sound” are used interchangeably throughout thus document
`because they are not practically separated. For example,
`detection of a sound refers to the same action as detection of
`
`a voice because, while the purpose is to detect the voice,
`other sounds are picked up as well.
`
`[0032] FIG. 1 is an illustration of an embodiment of an
`ear-level communication system 100 and portions of an
`environment in which it is used. System 100 includes an
`ear-level device 110 attached to an ear 101A. Ear-level
`
`device 110 communicates with a remote device 190 through
`a wireless telemetry link 195. The other ear 101B is free of
`device attachment. Ear-level device 110 is a self-contained
`
`device including its own power source such as a replaceable
`or rechargeable battery. To maximize battery life or period
`between recharges, at
`least a portion of the circuit of
`ear-level device 110 is voice activated. That is, ear-level
`device 110 is activated only when it detects a need to
`transmit or receive a sound.
`
`

`

`US 2005/0058313 A1
`
`Mar. 17, 2005
`
`[0033] Ear-level device 110 is a full duplex audio device
`that allows two-way simultaneous conversation between ear
`101A and remote device 190. In one embodiment, when
`being worn by a person having ear 101A, ear-level device
`110 picks up sound from the ear canal of ear 101A and
`delivers sound to the same ear canal. It detects the occluded
`
`sound from the ear canal when the person speaks and
`transmits to the same ear canal a sound received from remote
`
`device 190 and/or a sound picked up from the environment
`surrounding the person. In one embodiment, as illustrated in
`FIG. 1, ear-level device 110 is configured for right ear
`attachment. In an alternative embodiment, ear-level device
`110 is configured for left ear attachment.
`
`[0034] FIG. 2 is an illustration of an embodiment of an
`ear-level communication system 200 and portions of an
`environment in which it is used. System 200 includes a pair
`of ear-level devices 210A, attached to an ear 101A, and
`210B, attached to ear 101B. Ear-level devices 210A and
`210B communicate with a remote device 290 through a
`wireless telemetry link 295. Ear-level devices 210A and
`210B are each a self-contained device including its own
`power source such as a replaceable or rechargeable battery.
`To maximize battery life or period between recharges, at
`least a portion of the circuit of each of ear-level devices
`210A and 210B is voice activated. That is, ear-level devices
`210A and 210B are each activated only when a need to
`transmit or receive a sound is detected by the device itself.
`
`In one embodiment, ear-level device 210A is an
`[0035]
`audio transmitter that picks up sound from the ear canal of
`ear 101A, and ear-level device 210B is an audio receiver that
`delivers sound to the same ear canal. Ear-level device 210A
`is activated when it detects a sound from the ear canal.
`
`Ear-level device 210B is activated when it detects a signal
`from remote device 290. When both are being worn by a
`person, ear-level devices 210A and 210B supports full
`duplex audio allowing two-way simultaneous conversation
`between the person and remote device 290. In one embodi-
`ment, as illustrated in FIG. 2, ear-level device 210A is
`configured for right ear attachment, and ear-level device
`210B is configured for left ear attachment. In an alternative
`embodiment, ear-level device 210A is configured for left ear
`attachment, and ear-level device 210B is configured for right
`ear attachment.
`
`[0036] FIGS. 3A, 3B, and 3C are illustrations of exem-
`plary exterior configuration of ear-level device 110 or one of
`ear-level devices 210A and 210B. For the purpose of this
`document, only a device attached to a right ear is shown for
`each exemplary exterior configuration. It is to be understood
`that each of ear-level devices 110, 210A, and 210B can be
`either a device configured for right ear attachment or a
`device configured for
`left ear attachment. Generally, a
`device configured for right ear attachment has an exterior
`configuration that is substantially symmetrical to that of a
`device of the same type configured for left ear attachment.
`In system 100, a single ear-level device 110 is a device
`configured either for right ear attachment or for left ear
`attachment. In system 200, either one of ear-level device
`210A and 210B is a device configured for right ear attach-
`ment, while the other is a device configured for left ear
`attachment.
`
`[0037] An occluded sound 305, an ambient sound 306, and
`a remote sound 307 are illustrated in each of FIGS. 3A, 3B,
`
`and 3C. Remote sound 307 is represented by a wireless radio
`signal transmitted to ear-level device 110. In this document,
`“occluded sound” includes occluded sound 305, “ambient
`sound” includes ambient sound 306, and “remote sound”
`includes remote sound 307.
`
`[0038] FIG. 3A is an illustration of an exemplary exterior
`configuration of an in-the-ear (ITE) device 310A used as
`ear-level device 110 or one of ear-level devices 210A and
`210B. As shown in FIG. 3A, ITE device 310A is attached
`to an ear 101 with a pinna 302 and an ear canal 303. ITE
`device 310A includes a portion inserted into ear canal 303
`and another portion fit into the cavity formed by pinna 302.
`
`[0039] FIG. 3B is an illustration of an exemplary exterior
`configuration of an in-the-canal (ITC) device 310B used as
`ear-level device 110 or one of ear-level devices 210A and
`210B. As shown in FIG. 3B, ITC device 310B is attached
`to ear 101 with pinna 302 and ear canal 303. ITC device
`310B is a form of ITE device that also includes a portion
`inserted in ear canal 303 and another portion fit into the
`cavity formed by pinna 302, but the latter portion is smaller
`than that of ITE device 310A. Its overall size is therefore
`
`generally smaller than that of ITE device 310A.
`
`[0040] FIG. 3C is an illustration of an exemplary exterior
`configuration of a completely-in-the-canal
`(CIC) device
`310C used as ear-level device 110 or one of ear-level devices
`210A and 210B. As shown in FIG. 3C, CIC device 310C is
`attached to ear 101 with pinna 302 and ear canal 303. CIC
`device 310C is a form of ITC device but includes only a
`portion that is completed inserted into ear canal 303. Its
`overall size is therefore generally smaller than that of ITC
`device 310B.
`
`In one embodiment, each of ITE device 310A, ITC
`[0041]
`device 310B, and CIC device 310C includes a custom
`earmold. In another embodiment, each of ITE device 310A,
`ITC device 310B, and CIC device 310C includes a modular
`earmold. In one embodiment, the earmold is fully occluded
`to maximize audio efficiency. In another embodiment, the
`earmold is vented to remove undesirable low frequency
`sound.
`
`
`
`[0042] The choice of a device type, such as from the types
`shown in FIGS. 3A, 3B, and 3C, depends 01 the need of
`individual users. For example, ITE device 310A has a
`relatively large size to accommodate a relatively large
`amplifier to serve the need of individuals su ering severe
`
`hearing loss. The relatively large size can also 3e utilized to
`house a relatively large size battery. On the other hand, CIC
`device 310C is almost invisible, while the room for the
`circuit and the battery is very limited. Generally, the selec-
`tion of the device type is a compromise among consider-
`ations such as the user’s degree of hearing loss (if appli-
`cable), ear canal size, desire of invisibility, desired longevity
`between battery replacements or recharges, and cost.
`
`[0043] FIG. 4A is a block diagram showing one embodi-
`ment of the circuit of ear-level device shown in FIGS. 3A,
`3B, or 3C used as the single ear-level device 110. The circuit
`is housed in an earmold configured for use as one of the
`device types illustrated as ear-level devices 310A, 310B, or
`310C.
`
`[0044] Ear-level device 110 includes an external micro-
`phone 420, an ear canal microphone 440, an ear canal
`speaker 470, a processor 460, a Wireless transceiver 450, an
`
`

`

`US 2005/0058313 A1
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`Mar. 17, 2005
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`antenna 455, a voice operated exchange (VOX) circuit 430,
`and a battery 480. External microphone 420 picks up ambi-
`ent sound such that a hearing impaired person wearing
`ear-level device 110 is not “isolated” when communicating
`to remote device 190. Thus, ear-level device enables the
`hearing impaired person to talk to another person either
`directly (if the other person is nearby) or through a device
`such as a cell phone. Ear canal microphone 440 detects
`sound from the ear canal. The sound includes primarily
`speech of the person wearing ear-level device 110. Ear canal
`speaker 470 transmits sound received from remote device
`190 and/or external microphone 420 to the same ear canal.
`In one embodiment, ear canal microphone 440 and ear canal
`speaker 470 are implemented as one physical device. Pro-
`cessor 460 converts the sound picked up from the ear canal
`to an electrical signal to be transmitted to remote device 190,
`and converts the signals received from remote device 190
`and/or external microphone 420 to a sound audible to the
`person wearing ear-level device 110. In one embodiment,
`processor 460 includes one or more of amplification cir-
`cuitry, filtering circuitry, acoustic feedback reduction cir-
`cuitry, noise reduction circuitry, and tone control circuitry,
`among other circuits performing signal processing functions
`as known in the art. In one embodiment, processor 460
`includes a speech recognition module to enhance the audio
`signal received by and/or transmitted from ear-level device
`110. Wireless transceiver 450 and antenna 455 form a
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`telemetry interface supporting telemetry link 195 between
`ear-level device 110 and remote device 190. Wireless trans-
`ceiver 450 includes a wireless transmitter and a wireless
`receiver. The wireless transmitter receives the electrical
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`signal representing the sound picked up from the ear canal
`from processor 460 and transmits an outgoing wireless
`signal representing the same sound to remote device 190.
`The wireless receiver receives an incoming wireless signal
`representing a remote sound from remote device 190 and
`transmits an electrical signal representing the remote sound
`to processor 460. Telemetry link 195 provides for bi-direc-
`tional communication allowing simultaneous signal trans-
`mission, in both directions, between ear-level device 110
`and remote device 190. VOX circuit 430 activates a major
`portion of ear-level device 110 only when sound is detected
`by at
`least one of external microphone 420, ear canal
`microphone 440, and wireless transceiver 450.
`In one
`embodiment, VOX circuit 430 includes a voice-controlled
`switch connecting between battery 480 and the portions of
`ear-level device 110 that are voice activated. The switch is
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`driven by the sound detected by at least one of external
`microphone 420, ear canal microphone 440, and wireless
`transceiver 450. It is turned on when sound detected by
`external microphone 420 exceeds a predetermined thresh-
`old, when sound detected by ear canal microphone 440
`exceeds another predetermined threshold, and/or when wire-
`less transceiver 450 receives the incoming wireless signal
`representing the remote sound. In one embodiment, as
`discussed with respect to FIG. 4B below, VOX circuit 430
`gates or attenuates one or more sounds detected by external
`microphone 420, ear canal microphone 440, and wireless
`transceiver 450,
`to eliminate or reduce echo and ringing
`caused by the loop formed by ear canal speaker 470 and ear
`canal microphone 440. Battery 480 supplies the power
`needed for the operation of ear-level device 110. In one
`
`embodiment, battery 480 is a rechargeable battery that can
`be recharged without being taken out from ear-level device
`110.
`
`[0045] FIG. 4B is a block diagram showing one embodi-
`ment of portions of VOX circuit 430. In this embodiment,
`VOX circuit 430 includes an ambient sound gating module
`421 that blanks or attenuates the sound detected by external
`microphone 420, an occluded sound gating module 441 that
`blanks or attenuates the sound detected by ear canal micro-
`phone 440, a remote sound gating module 451 that blanks or
`attenuates the sound detected by wireless transceiver 450,
`and controller 431 to coordinate the states of the gating
`modules. Because ear canal microphone 440 is capable of
`detecting the sound delivered to the ear canal from ear canal
`speaker 470, there is a need to avoid echo and/or ringing. For
`example, a remote sound from remote device 190 delivered
`to the ear canal may be detected as an occluded sound and
`transmitted back to remote device 190, causing echo. The
`gating modules function in a coordinated manner to elimi-
`nate or reduce such echo and/or ringing caused by breaking,
`or applying resistance into, the audio loop formed by ear
`canal speaker 470 and ear canal microphone 440.
`
`For the purpose of description, each of the gating
`[0046]
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`modules is “on” when sound is “gated on” and “off” when
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`
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`the sound is “gated o .” A sound is “gated on” when it is
`allowed to pass and be processed, and is “gated off" when
`it is blanked or substantially attenuated. Blanking refers to
`a substantially complete blockage of a sound, or in other
`words,
`that a detected sound is practically ignored by
`processor 460 such that it does not cause any echo or ringing
`that is audible by an ear. Substantial attenuation refers to an
`attenuation after which the attenuated sound does not cause
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`any echo or ringing having an intolerable intensity.
`[0047] Ambient sound gating module 421 includes a
`voice-driven switch or attenuator driven by the output of a
`comparator that compares the amplitude of a detected ambi-
`ent sound with a predetermined threshold for the ambient
`sound. When the amplitude of the detected ambient sound
`exceeds the threshold for the ambient sound, and when
`controller 431 permits, ambient sound gating module 421 is
`turned on. When the amplitude of the detected ambient
`sound drops below the threshold for the ambient sound,
`ambient sound gating module 421 is turned off. In one
`embodiment, after the amplitude of the detected ambient
`sound drops below the threshold for the ambient sound,
`ambient sound gating module 421 is turned off after a
`predetermined delay.
`[0048] Occluded sound gating module 441 includes a
`voice-driven switch or attenuator driven by the output of a
`comparator that compares the amplitude of a detected
`occluded sound with a predetermined threshold for the
`occluded sound. When the amplitude of the detected
`occluded sound exceeds the threshold for the occluded
`
`sound, and when controller 431 permits, occluded sound
`gating module 441 is turned on. When the amplitude of the
`detected occluded sound drops below the threshold for the
`occludec sound, occluded sound gating module 441 is
`turned off. In one embodiment, after the amplitude of the
`detected occluded sound drops below the threshold for the
`occludec sound, occluded sound gating module 441 is
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`turned 0
`after a predetermined delay.
`[0049]
`In one embodiment, remote sound gating module
`451 includes a voice-driven switch or attenuator driven by
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`US 2005/0058313 Al
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`Mar. 17, 2005
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`the output of a comparator that compares the amplitude of a
`remote sound with a predetermined threshold for the remote
`sound. When the amplitude of the detected remote sound
`exceeds the threshold for the remote sound, and when
`controller 431 permits, remote sound gating module 451 is
`turned on. When the amplitude of the detected remote sound
`drops below the threshold for the remote sound, remote
`sound gating module 451 is tL med off. In one embodiment,
`after the amplitude of the cetected remote sound drops
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`3elow the threshold for the remote sound, remote sound
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`gating module 451 is turned 0
`after a predetermined delay.
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`sound to remote device 190, and prevents the same sound
`from being transmitted to remote device 190 twice. Other
`rules are applied as a person skilled in the art should see fit
`based on an understanding after reading this entire docu-
`ment.
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`[0053] FIG. 5 is a block diagram showing another
`embodiment of the circuit of ear-level device shown in
`FIGS. 3A, 3B, or 3C used as each of ear-level devices 210A
`and 210B. The circuit of each of ear-level devices 210A and
`
`210B is housed in an earmold configured for use as of one
`of the device types illustrated as ear-level devices 310A,
`310B, or 310C.
`
`[0054] Ear-level device 210A is an audio transmitter that
`includes an ear canal microphone 540, a processor 560A, a
`wireless transmitter 550A, an antenna 555A, a transmitter
`VOX circuit 530A, and a battery 580A. Ear canal micro-
`phone 540 detects sound from the ear canal. The sound
`includes primarily speech of the person wearing ear-level
`device 210A. Processor 560A converts the sound picked up
`from the ear canal to an electrical signal to be transmitted to
`remote device 290. In one embodiment, processor 560A
`includes one or more of amplification circuitry, filtering
`circ