WO1994025957A1

WO1994025957A1 - Voice transmission system and method for high ambient noise conditions

Info

Publication number: WO1994025957A1
Application number: PCT/US1993/003996
Authority: WO
Inventors: George M. Stites, Iii
Original assignee: Intelex, Inc., Dba Race Link Communications Systems, Inc.
Priority date: 1990-04-05
Filing date: 1993-05-03
Publication date: 1994-11-10
Also published as: US5327506A

Abstract

An earpiece has a structural configuration effective to removably interlock its outer surface contiguously to the outer ear auricle of the earpiece wearer. A microphone substantially exclusively receives, from the air of the external auditory canal, outbound voice sounds caused by the reverse modulation of the tympanic membrane when the earpiece wearer speaks. An outbound audio circuit is electrically connected to the microphone which converts the outbound voice sounds to electrical voice signals. The outbound audio circuit amplifies the outbound electrical voice signals to a preselected fixed level output gain and removes noise from the voice signals. A specific feature of the unique noise cancellation system, a noise cancelling signal is produced from a noise sample and used to oppose any noise portion of the outbound voice sounds.

Description

VOICE TRANSMISSION SYSTEM AND METHOD FOR HIGH AMBIENT NOISE CONDITIONS

Field of the Invention

This invention relates to transmitting and receiving voice sounds through the external auditory ear canal under high ambient noise conditions. More particularly, the

invention relates to a voice transmission system and method for cancelling noise in a voice sound outbound from a person's ear canal.

Background of the Invention Numerous attempts have been made to provide voice communication within environments having a high ambient noise level. Particularly, it has been desirable to provide a system in high ambient noise conditions as found in aviation, competitive motor sports such as racing cars and boats, industrial plants, crowd noise, public safety and military operations. U.S. Patent 4,150,262 shows a typical voice transmission system having an earpiece formed to fit into the external auditory canal.

U.S. Patent 4,588,867 discloses an ear microphone comprising a pickup piece having a vibration/electrical signal converter element. When voice communication through the ear canal depends upon audio vibration pickup via bone and tissue conduc- tion, it is virtually impossible for such prior art devices to be used under ambient condi¬

tions where the noise levels are greater than 90 decibels.

U.S. Patent 2,938,083 shows an earpiece disposed at the opening of the external auditory canal while the speaker and amplifier system is located outside the earpiece member.

The in-ear hearing aid disclosed in U.S. Patent 2,987,584 includes a canal extension section having a structural configuration for maintaining the earpiece in position without slipping or using exterior clamps for holding the unit to the ear.

Reissue Patent 26,174 discloses a hearing aid earpiece structure that fits the outer ear and a portion of the auditory canal.

U.S. Patent 2,535,063 discloses the typical commercially available two-way communication systems having two channels which are mutually exclusive whereby the operator must either transmit or receive but cannot hear himself speak when transmitting. U.S. Patent 3,819,860 discloses an ear-borne transceiver, unworkable in high ambient noise, using two audio passageways that are continuously open at all times and include a filter mechanism for eliminating background noise.

Noise free voice transmission through the external auditory canal under high ambient noise conditions at noise levels greater than about 90 decibels has heretofore been unattainable. The noise levels within the higher decibel range are known to have an exponential character. For example, at 100 decibels there is a certain noise level. At

103 decibels the noise level is about twice as great as at 100 decibels. At 106 decibels the sound pressure level is again twice that found at 103 decibels and so forth. At ambient noise levels of about 125-130 decibels, clear voice transmission through the auditory canal is new and unexpected.

The best boom microphone system using a mike located in front of the mouth is incapable of performing at a noise level or sound pressure much over about 110 decibels.

Under these conditions, the boom mike will be substantially resting directly on the lips.

Consequently, under such conditions as found in competitive motor sport events, the

boom mike simply gets in the way because of the activity in the driver's cockpit.

With respect to the patent disclosures discussed above, at the noise levels of greater than about 90 decibels and up to about 140 decibels, the bone and tissue of the earpiece wearer would transmit external noise significant enough to render these prior art devices incapable of clear voice transmission.

Summary of the Invention

The assembly of the invention comprises means for picking up the outgoing voice sounds substantially exclusively from the air within the external auditory canal of a person while substantially eliminating audio vibration pickup of sound transmitted by bone conduction. The assembly is particularly useful under high ambient noise condi¬ tions.

The method of the invention comprises transmitting a person's outgoing voice sounds to a remote location substantially exclusively from the air within the external auditory canal. The internal voice box through the eustachian tube causes the tympanic

membrane to modulate. Thus, by definition, this is referred to herein as reverse modula¬

tion of the tympanic membrane.

The voice transmission method of the present invention is directed to picking up minute air pressure changes in the outer ear canal. The pressure changes are caused by the reverse modulation of the tympanic membrane substantially exclusively from the air within the external auditory canal of the person doing the speaking. Those voice sounds are converted to an electrical voice signal without a noise portion and having a preselect¬ ed fixed level output gain. The resultant electrical voice signal is then directed to means for transmitting a clear voice sound of the person at a location remote from the person doing the speaking. Such transmission is effective under ambient conditions having a noise level greater than about 90 decibels and up to noise levels in the range of about 115 to 140 decibels.

It has been discovered that the air pressure in the air chamber should be maintained at equilibrium with the air pressure in the inner ear. The air chamber is sealed to preclude sound from entering the auditory canal and an inner sound attenuating chamber is disposed at the entrance of the auditory canal to help substantially eliminate audio vibration pickup of sound transmitted by bone and tissue conduction.

The outer surface of the earpiece canal extension section is spaced inwardly from the wall of the auditory canal. Annular gasket means, disposed around the canal exten¬ sion member and extending to the canal wall, effectively maintains the position of the canal extension section away from the wall. Such sound gasketing avoids audio vibration pickup of sound transmitted by the canal wall. Furthermore, the gasket composition dampens any audio vibration pickup of sound through the gasket material touching the canal inner wall. A particular feature of the invention provides control circuit means for alter¬ nately transmitting sound through one of the sound passageway means while the other

passageway means is closed to the transmission of sound. The control circuit means,

speaker means and microphone means are located outside the earpiece. Means is provided for disposing the speaker means and microphone means at a location on the wearer's body away from the wearer's head.

Another feature of the invention is directed to the sampling of a noise sound to oppose the noise portion of any audio sound picked up in the auditory ear canal. In one embodiment, a noise sampling chamber is disposed in the earpiece canal extension section. The noise sound is converted to an electrical signal and opposed in a circuit that cancels the difference between the voice sound signal and the sampled noise sound signal.

The amplified differential is then transmitted with any known audio out system.

Brief Description of the Drawings

FIGURE 1 is an elevational view of an earpiece assembly in accordance with this invention; FIGURE 2 is another embodiment of an earpiece assembly in accordance with this inventi FIGURE 3 is a cross-sectional view of a sound transmitting earpiece member in

accordance with this invention;

FIGURE 4 is an elevational view, partially in section, of an earpiece assembly in accordance with this invention; FIGURE 5 is a schematic flow diagram showing the functioning portions of the voice transmission system in accordance with this invention; and

FIGURE 6 is a circuit diagram showing the control circuitry in accordance with this invention.

FIGURE 7 is a schematic flow diagram showing a noise cancellation system in a voice transmission assembly according to the invention;

FIGURES 8 and 9 are schematic flow diagrams showing other embodiments of a noise cancellation system according to the invention;

FIGURE 10 is a circuit diagram showing control circuitry for a noise cancellation system of the invention; FIGURE 11 is a schematic diagram of mechanical noise cancellation system for the earpiece of the invention; and

FIGURE 12 is a schematic diagram of the unique ear canal noise cancellation system of the invention.

Detailed Description of the Invention The voice transmission assembly, generally designated 10 in Figure 1, comprises an earpiece member 11 having a body portion 12 and a canal extension section 13. End ports 14 of inbound tube 15 and outbound tube 16 open to respectively send and receive sounds to and from the tympanic membrane of the earpiece user. Inbound and outbound tubes 15 and 16 extend from end ports 14 through canal extension section 13 to respec-

tive outlet sound and inlet sound ports on speaker 18 and the unidirectional microphone

17 physically mounted to circuit board member 19.

A rigid material such as an epoxy resin encapsulates the speaker/microphone module 20 wherein microphone 17 and speaker 18 are electrically connected to circuit board member 19. Electrically connecting means 22 electrically connect plug 24 via con- necting line 23. Plug 24 is a standard jack as shown and is used to electrically couple the voice transmission assembly 10 to an audio controller unit discussed below.

In another embodiment of the invention, an earpiece assembly, generally designated 25, comprises an earpiece member 26 having a body portion 27 and a canal extension section 28. End ports 29 of inbound tube 30 and outbound tube 31 respectively couple at the other end thereof to outlet sound port 30A and inlet sound port 31 A of the speaker 33 and microphone 32. In this specific embodiment, the speaker/microphone module 35 is encased in an epoxy potting material and is disposed at a location outside the earpiece member 26. Module 35 comprises microphone 32 and speaker 33 physically coupled and electrically connected to the circuit board member 34. Electrical connecting means 37 electrically connect circuit board member 34 to a plug (not shown) via connecting line 38 as in the first embodiment discussed above. The body portions 12 and 27 of the respective embodiments shown in Figure 1 and

Figure 2 are composed of a flexible shell which defines an attenuating chamber through which the inbound and outbound tubes for each embodiment extend. The outer shell por¬ tion is composed of molded vinyl material and is custom-made for fitting individualized

ear structures in the well known manner used to form earpieces for hearing aids.

However, the outer diameter and structure of the canal extension sections 13 and 28

of the embodiments of Figure 1 and Figure 2 are such that the outer surfaces thereof are spaced inwardly from the wall of the external auditory canal when the assemblies 10 and 25 are placed into the outer ear of a user. The structural configuration of earpiece

members 11 and 26 have an outer surface effective to removably interlock contiguously

to the outer ear auricle of an earpiece wearer. The particular structural configuration of

earpiece members 11 and 26 is effective to substantially eliminate audio vibration pickup of sound transmitted via bone and tissue conduction within the head of the earpiece user. The detailed structural configuration of the earpiece elements of this invention is

shown in the embodiment of Figure 3. A sound transmitting earpiece member or element

41 has a body portion 42 composed of a pliable material forming a thin, flexible outer

shell 43 defining an inner sound attenuating chamber 44. Element 41 is first molded as a solid and then excavated to form chamber 44. A plastic material such as silicone is usable to form element 41.

A base support wall 45 of body portion 42 carries a coupling means 46 as shown.

Body portion 42 includes a canal extension section 47 having a diameter to form an outer surface 48 which is spaced inwardly from the wall of the auditory canal when earpiece element 41 is removably interlocked contiguously to the wearer's outer ear auricle.

The purpose of this structural configuration is to eliminate any audio vibration pickup of sound via bone conduction within extension section 47. Annular gasket member 49 is disposed around canal extension section 47 and is composed of a sponge material which constitutes a sound vibration dampening means between the external

auditory canal wall and outer surface 48 of extension section 47. As is evident in the drawings and the written disclosure, gasket member 49 isolates end ports 14 and canal extension section 13 to effect the substantial elimination of audio vibration pickup of sound via bone and/or tissue conduction.

A tube retaining structure 50 at the sealed end of extension section 47 secures inbound end port 51 and outbound end port 52 for voice sound movement (Arrow A) toward the tympanic membrane while voice sound movement moves from the canal air space (Arrow B) into outbound tube 54. Tubes 53 and 54 constitute two sound passage- way means wherein tube 53 is effective, when open, to transmit sound to the tympanic membrane and tube 54 is effective to receive sound from the auditory canal air space which is caused by reverse modulation of the tympanic membrane when the earpiece wearer speaks. The flexible tubes may be composed of a silicone or like material. Retaining structure 50 works to maintain the tube end ports away from the wall of the auditory canal thereby dampening sound vibration by bone conduction.

Inbound tube 53 and outbound tube 54 extend along canal extension 47 through sound attenuating chamber 44 and outwardly to a microphone module (not shown) as

disclosed in the earlier embodiments. Inner sound attenuating chamber 44 is filled with additional sound dampening material to preclude the entry of external sound into the external auditory canal. Additionally, the filler dampening material is chosen to enhance the elimination of audio vibration pickup of sound by flexible tubes 53 and 54 extending through chamber 44. In this embodiment, chamber 44 is filled with high noise attenuat¬

ing fibers.

Annular gasket 49 compresses substantially totally to seal around the inner wall of the auditory canal and extension section surface 48 to provide a canal air chamber within which voice sounds move from the tympanic membrane into outbound tube 54. Sound moves freely toward the tympanic membrane through the canal air chamber as schemati¬ cally shown in Figure 5 (Arrow A - inbound; Arrow B - outbound). Here the overall disposition of the earpiece assembly and audio controller unit is shown in relationship to the earpiece wearer. The earpiece structure of the embodiments in Figures 1 through 3 is effective to provide a clear voice transmission within a high ambient noise environment wherein the noise level is greater than 90 decibels and up to about 100 decibels. Whenever the noise level reaches about 100 decibels, it has been found that the assembly, generally designat¬ ed 55 in Figure 4, achieves the unexpected results in attaining a clear voice transmission up to a noise level in the range of from about 120 to about 125 decibels or higher. Such operable voice transmission has never before been achieved at these ambient noise levels. In the embodiment of Figure 4, a sound dampening section 56 is removably mounted to the sound transmitting section 41 using coupling means 57 which is a Velcro connecting mechanism. Alternatively, earpiece element 41 may be permanently secured to sound dampening section 56 where its continuous use is in an extremely high noise level environment.

Sound dampening section 56 includes an external sound barrier portion 59 contigu¬

ous to an ear sealing surface portion 58. Sound dampening section 56 includes a surface recess 60 having a shape and size sufficient to receive sound transmitting element 41 as shown. Coupling means 57 is disclosed in recess 60 for removably mounting sound transmitting element 41 to sound dampening section 56. Inner sealing membrane 61 is composed of polyethylene and disposed on sealing surface portion 58 where it acts as a sealing surface membrane. Sealing surface portion 58 is composed of conformable material comprising an open-cell polyurethane foam.

Sealing surface portion 58 contiguously interlocks with the structure of the outer ear auricle with inner sealing membrane 61 being effective to block the in-flow of external noise to the auditory canal air chamber. Barrier portion 59 is composed of a more rigid barrier foam such as a closed-cell polyurethane foam covered by a surface barrier layer or membrane 62. Barrier portion 59 is designed to prohibit the inbound movement of external noises to the canal air chamber. Cover tube 65 is disposed around tubes 63 and 64 extending outwardly from the sound transmitting element 41 to the speaker/micro¬ phone module (not shown) in this embodiment. A similar cover tube is found around the sound passageway tubes of the earlier described embodiments.

The schematic flow diagram of Figure 5 illustrates the voice transmission system which unexpectedly achieves clear or substantially noise free voice transmission via the outer ear canal within high ambient noise conditions at noise levels in excess of about 90 decibels. Earpiece 41 has a structural configuration which interlocks to the outer ear

auricle of the wearer. Extension section 47 projects outwardly from the body portion into the auditory ear canal at a spaced distance from the wall of the auditory canal. The end ports are spaced at a distance of about one quarter (1/4) of an inch or less from the tympanic membrane. The annular gasket 49 around extension section 47 seals the canal air space between the end of extension section 47 and the tympanic membrane. Due to the structural configuration of earpiece 41 and gasket 49 around extension section 47, audio vibrations being conducted by the bone and tissue of the earpiece wearer is substantially eliminated. The assembly of the invention substantially exclusively obtains voice sound from the sealed canal air space into an end port of the outbound tube connected to the inlet sound port of the microphone. When the person wearing the earpiece speaks, reverse modula¬ tion of the tympanic membrane causes voice sounds to flow outwardly (Arrow B). The microphone converts voice sound to electrical voice signals directed to an audio controller unit which includes control circuitry. A push-to-talk (PTT) switch mechanism switches between outbound audio circuit means and inbound audio circuit means of the control circuitry. In this specific embodiment when a button is pushed by the earpiece user, his voice sound travels outbound from the tympanic membrane through the microphone into the audio controller unit. Upon release of the switch button, the outbound tube is closed and the inbound tube is opened. Inbound electrical sound signals are converted by speaker means into sounds which travel through the eaφiece and the enclosed canal air chamber to the tympanic membrane. Such sound transmission is accomplished via the eaφiece of the invention which substantially eliminates audio vibration pickup of sound via bone and

tissue conduction.

The switch mechanism may also be constructed as a voice activated system. Whenever the eaφiece user speaks, the electrical voice signals from the microphone in the speaker/microphone module automatically activates the outbound audio circuit and allows the desired outbound voice transmission.

Once the electrical voice signal passes through the control circuitry it is directed to a radio transceiver which then puts out an appropriate signal that is picked up by a second radio transceiver remote from the location of the first radio transceiver unit. The first transceiver unit incoφorates the audio control circuit and is disposed in a unit which may be worn on the belt of the eaφiece user.

The remote radio transceiver may be electrically connected to a loud speaker or to another eaφiece assembly made in accordance with this invention at the remote location. Alternatively, a hard wire connection between the first and second transceiver units may be used to effect two-way communication within high ambient noise levels in a range of up to 120 to 125 decibels.

Typical voice grade quality of this invention gives a response of between 300 and 3000 cycles per second. The control circuit as shown in Figure 5 includes an outbound audio circuit portion designated "microphone" and an inbound audio circuit portion designated "RX audio." The amplifier means of the invention amplifies, impedance matches and buffers the outbound audio electrical signals. The output of the ear micro¬ phone is coupled to a variable input compression amplifier Ul via capacitors Cl and C2 which remove all sound in the frequency range of below about 500-600 cycles per second. Operational amplifier 70 handles feedback and works in concert with com- pression amplifier Ul which amplifies the electrical signal to a preselected fixed gain.

The output 7 of compression amplifier Ul is capacitively coupled to the input of opera¬ tion amplifier 71 where it is further amplified. That is, the predetermined gain level is preselected and set to a second stage gain level via variable resistor VR1. Operational amplifier 71 is coupled to a third stage operational amplifier 72 where the outbound audio signal is buffered so that any variations in the first two stages will not adversely affect input of processor U3 at connection 2 thereof. Processor U3 actively separates or filters the noise portion of the electrical voice signal from the voice portion thereof using the rate of change of frequency to identify voice signals and attenuate noise audio signals not identified as voice. The noise portion of the audio signal is directed to ground.

The output of processor U3 is then directed to a fourth stage operational amplifier 73 where the signal is applied as set by potentiometer VR3 and capacitively coupled to the output of the transmit audio board at pin 4 of connection PI. Operational amplifier

73 buffers against variations in radio transmission. Power is supplied to the transmit audio board from a direct current supply to pin 1 and is divided, decoupled, filtered and regulated by the circuitry in series with pin 1 (between C26 and C16 on the circuit diagram).

The transmitter is actuated by a push-to-talk (PTT) switch which leaves the transmit audio board at pin 9 of connector PI after being radio frequency (RF) decoupled and provides closure to ground. Radio receive (RX audio) is routed to the eaφiece after being RF decoupled via C27 upon entering the transmit audio board at P2 of connector

PI. The inbound circuit means includes RX audio at pin 2 and routed to RX audio at the other side of the circuit where it is electrically connected to the speaker means for sending inbound sounds to the tympanic membrane through an inbound flexible tube to the sealed canal air space.

Noise Cancellation System

Figure 7 shows the voice transmission system 100 with a noise cancellation modification that incoφorates a 180 degree phase and frequency opposing principle for substantially eliminating the noise component from the ear canal signal. Eaφiece 141 has a structural configuration that interlocks to the outer ear auricle of the wearer. Extension section 147 projects outwardly from the body portion into the auditory ear canal at a spaced distance from the wall of the auditory canal. The end ports are spaced at a

distance of about one quarter (1/4) of an inch or less from the tympanic membrane.

The annular gasket 149 disposed around extension section 147 seals the canal air space between the end of extension section 147 and the tympanic membrane. As in the earlier embodiment of Figure 5, the structural configuration of eaφiece 141 and gasket

149 around extension section 147 substantially eliminates audio vibrations conducted by

the bone and tissue of the eaφiece wearer.

This assembly of the invention operates in substantially the same manner as the earlier embodiment of Figure 5 with the additional use of an outside ambient noise pickup port 102. Pickup port 101 sample outside noise. Tubing 155 directs the ambient noise to microphone 122, which converts air pressure to an electrical signal that is sent to the control circuit via a hard wire connection. The control circuit processes the two electrical signals from microphones 111 and 112 for cancellation of the noise component of the voice sound audio picked up by port 101. As in the earlier embodiment of Figure 5, the eaφiece user pushes a button to have his voice sound travel outbound from the tympanic membrane through the port 101 to microphone 111 into the audio controller unit as an electric signal. Upon release of the switch button, the outbound tube 154 is closed and the inbound tube 153 is opened. A voice actuation system may be used instead of the button to eliminate the need for manual activating for voice transmission. Voice actuation is particularly useful if eaφieces are used in both ears of the user or for simultaneous transmission and reception of voice signals. Inbound electrical sound signals are converted by speaker 113 into sounds which travel through eaφiece 141 and the enclosed canal air chamber to the tympanic membrane. A duplex system may be used in place of the single ear use disclosed herein. In a duplex system, inbound electrical sound signals are delivered to both ears by use of a second eaφiece in the user's other ear. The sound transmission is effected as in the earlier embodiment.

The control circuit of Figure 8 and 9 produces an amplitude and phase equalization of the voice sound electrical signal and noise cancelling electrical signal transmitted from the voice chamber and noise sampling chamber, respectively. The control circuit receives (1) a voice audio electrical signal and cancelling noise audio electrical signal, (2) opposes the inputs, and (3) rejects their common mode.

In Figure 8, eaφiece 200 is electrically connected as in earlier embodiments of Figures 5 and 7. Figure 9 shows eaφiece 200 electrically connected to the control circuit of the invention to develop an audio output signal for transmission by any known electrical system. Figure 8 shows an inbound voice sound signal from speaker 215 through tube 216 disposed along the bottom of eaφiece 200 into the auditory canal chamber. Speaker 215A of Figure 9 is located within the body of the eaφiece as shown. The inbound voice sound signal travels through tube 216A along the top portion of eaφiece 200A in Figure 9. Otherwise the two eaφieces 200 and 200A operate in the same manner.

Explanation of the sectional view in Figure 9, applies to corresponding parts in Figure 8. Barrier gasket 213A sound insulates voice pickup chamber 212A from noise

sampling chamber 222A. Noise sampling chamber 222A has a mixture of ambient noise and voice audio sound. Chamber 212A receives a voice sound signal that is predomi¬ nantly voice with a lesser component of noise. Chamber 222A samples a noise sound that is predominantly noise with a lesser component of voice. Sound sampling ports

210A and 220A are very close together so the respective phase of each sound signal is very close.

The eaφiece is designed to minimize the voice portion in chamber 222A because a noise cancelling electrical signal opposes any noise and voice components of the voice sound electrical signal developed from the voice sound obtained by port 210A. The opposing or cancelling function is performed more completely in the control circuit of Figure 10. The extent of the voice sound signal in chamber 222A will cancel the voice sound signal of chamber 212A. Thus, the amount of the voice component in chamber 222A must be minimized. Microphone units 210A and 220A in chambers 212A and 222A, respectively, each have a tubular air pressure intake connected to a transducer. The three connections on the sound transducers of the microphone units 210A and 220A include one for voltage, which is at about 2 volts each. The second connection is audio output. The third connection is ground or common for both the audio and the voltage. The changes in air pressure caused by the voice and noise sound components are changed to electrical signals that are transmitted by electrical leads 211 and 221 to control circuit 230 that amplifies the opposing electrical signals and rejects the like portions existing in the electrical signals. A differential amplifier in control circuit 230 amplifies

only the difference between the two signals.

More specifically, for example, the noise level in chamber 212A is 20% of the total signal with 80% being voice. The noise sampling chamber 222A is predominantly noise.

A sound sample from chamber 222A is about equal to the noise portion of the voice sound signal in chamber 212A. The percentages of the noise and voice portions are

based on the noise and voice levels in each sound signal. The closer the noise levels in chambers 212A and 222A, the better the device works. In other words, if the noise level in chamber 222A equals the noise level in chamber 212A, there is a perfect match and all noise is then cancelled from the voice sound electrical signal in control circuit 230.

The control circuit of Figure 10 is used to substantially eliminate the noise compo¬ nent from the voice sound picked up by microphone A in the voice sound chambers of the embodiments in Figures 7, 8 and 12. Microphone B picks up the noise cancelling sound from the noise sampling chamber. Microphones 241 and 242 are A mic and B mic, respectively.

Shield 243 keeps out any induced electromotive force (EMF) or radio frequency interference (RFI) because the system is running at low level audio. The equalization of capacitances between the wires, the conductors in the cable, and the shield contribute to preparing the signals for input to differential amplifier 240.

Operational amplifier 248 amplifies the minute fluctuations that amplifier 240 will oppose. With amplifiers 240, 248, and 249 connected as shown, if there is any stray

capacitance that is induced on the shield, some of it is induced out of the conductor.

Then, the circuit makes adjustment so that the audio signal will not be hampered by this fluctuation. The inputs from microphones 241 and 242 run through a 10K potentiometer to balance the noise levels. The value of the potentiometer could be different depending on the eaφiece. The filters 246 and 247 are designed to eliminate any sound signal below

300 cycles such as motor noise. Voice grade communications is placed between 300 and

3000 cycles or Hertz. The two electrical signals of mics A and B are directed to inputs 1 and 2 of amplifier 240 which identifies the signals and cancels the noise components on input 1 and input 2 to produce a clear voice signal at the output of amplifier 240. Amplifier 240 takes the plus input signal and minus input signal and amplifies the difference. All common input signals are cancelled or erased. The differential is the resultant substan- tially noise-free voice signal.

A significant aspect of the invention is to deliver the amplitude and phase as closely as possible from voice audio port to the noise sampling port of the electrical sound signals of the eaφiece. The more closely the phase and amplitude are aligned, the better is the equalizing of the two signals. The method includes setting up the appropriate insulation between chamber A and chamber B. The insulation blocks 213A and 223A effect primary equalization of the sound signals within the eaφiece. Further equalization is effected electrically between the mics A and B as shown in the circuit diagram of

Figure 10.

The electrical sound signals are in the range of about 2 to about 10 millivolts in the voice sound chamber. See Figure 11. The noise component is about 2 millivolts if the total voice sound chamber is about 10 millivolts. The eaφiece is made to recreate about two millivolts of noise in the noise sampling chamber to oppose the noise component in

the voice sound signal at about 10 millivolts obtained in the voice or auditory chamber.

The power supply includes two nine volt batteries. With the 7.5 volt Zener diodes and capacitors, the respective voltages are balanced to regulate the supply voltage at 7.5 volts. Amplifier 240 produces a gain of 10 at pin 13 for the signal from operational amplifier 248. Amplifier 240 also matches and balances the two signals for effecting the desired noise cancellation. Potentiometers 250 and 251 are connected to null inputs and outputs to enhance signal balancing. Potentiometer 253 controls the output signal for transmission after noise is cancelled from the voice sound signal. Figure 11 shows another embodiment of the noise cancellation system having a mechanical diaphragm that separates two sound chambers in an eaφiece projection disposed within the ear canal. The mechanical diaphragm literally cancels the noise components within the eaφiece. Thus, only the voice sound is transmitted to an electrical amplifier circuit. The mechanical diaphragm may be made of Mylar or polypropylene and is impervious to air. The very thin membranes are pressure sensitive to minute changes in pressure. The idea is that the membrane or diaphragm holds still by virtue of equal pressure

created by noise on each side. Variable or differential pressure is caused by the voice,

which pushes against the diaphragm and modulates it as voice.

A piezo transducer material might be used to transmit an electrical signal based on a difference of potential. When bent, the piezo material produces a variance in voltage, i.e., fluctuation in voltage from one end of the material to the other. This material needs no battery to record a change voltage. With this embodiment, the noise cancellation is mechanical rather than electrical. Therefore, the control circuit will just amplify and filter out desired portions such as the lower 300 cycles. In this mechanical embodiment, adjustments to amplitude and phase are unnecessary.

While the voice transmission system and method for high ambient noise conditions have been shown and described in detail, it is obvious that this invention is not to be considered as limited to the exact form disclosed, and that changes in detail and con¬ struction may be made therein within the scope of the invention without departing from the spirit thereof.

Claims

CLAIMSHaving thus set forth and disclosed the nature of this invention, what is claimed is:

1. A voice transmission system comprising: a) eaφiece means having sound dampening means and an outer surface effective to removably interlock contiguously to the outer ear auricle of a wearer of the

eaφiece means, b) first speaker means for sending inbound sounds and first microphone means for receiving outbound voice sounds respectively to and from the tympanic membrane of said wearer, c) said first speaker means and first microphone means being structurally and electrically connected to a circuit board member to form a speaker/microphone module, d) said circuit board member including means for electrically connecting and transmitting inbound electrical audio signals to the first speaker means and means for electrically connecting and transmitting outbound electrical voice signals from the first microphone means to control circuit means, e) said control circuit means including outbound audio circuit means and inbound audio circuit means, said outbound audio circuit means being electrically connected to said first microphone means and said inbound audio circuit means being electrically connected to said first speaker means, f) second speaker means disposed at a location remote from said person for receiving said outbound electrical voice signals from the first microphone means, and

g) second microphone means disposed at a location remote from said person

for forwarding said inbound electrical audio signals to said first speaker means, h) said sound dampening means being disposed to isolate the eaφiece means for substantially eliminating audio vibration pickup of sound transmitted by bone and

tissue conduction.

2. A system as defined in Claim 1 wherein the eaφiece means includes flexible tube members at one end thereof having end ports which open outwardly from a canal extension section, each of said tube members being connected at the other end thereof to a respective voice sound inlet of the first microphone means and a sound outlet of the first speaker means, said speaker/microphone module is encapsulated in a molded rigid material and disposed within the eaφiece means.

3. A system as defined in Claim 1 wherein the eaφiece means includes flexible tube members at one end thereof having end ports which open outwardly from a canal extension section, each of said tube members being connected at the other end thereof to a respective voice sound inlet of the first microphone means and a sound outlet of the first speaker means, said speaker/microphone module is disposed at a location remote from said

eaφiece means.

4. A system as defined in Claim 3 wherein said outbound audio circuit means includes amplifier means and processor

means,

said amplifier means being effective to amplify an intelligible electrical audio signal to a preselected fixed level output gain for producing an increased gain audio signal having a voice portion and a noise portion, said processor means being effective to separate the noise portion from the voice portion for producing a clear voice sound to be transmitted by said second speaker means.

5. A system as defined in Claim 4 wherein the inbound audio circuit means is effective to send inbound electrical audio signals from said second microphone means to the first speaker means which responsively sends sounds to the external auditory canal of said wearer.

6. A system as defined in Claim 1 wherein said second speaker means and said second microphone means are disposed in a single transceiver unit at the same remote location.

7. A system as defined in Claim 1 wherein said control circuit means includes switch means for alternately activating the

inbound audio circuit means and the outbound audio circuit means.

8. A system as defined in Claim 1 wherein the eaφiece means includes two separate and independent sound passageway means having end ports open to respectively send and receive sounds to and from the tympanic membrane of said wearer, one of the passageway means being connected to the first speaker means and the other passageway means being connected to the first microphone means.

9. A system as defined in Claim 8 wherein each of the two sound passageway includes a hollow flexible tube coupled to a respective sound output port and sound input port of the speaker/microphone module.

10. A system as defined in Claim 1 wherein the eaφiece means includes a sound transmitting section having two separate and independent sound passageway means having end ports open to respectively send and receive sounds to and from the tympanic membrane of said wearer, said sound dampening means includes an ear sealing surface portion composed of conformable material that contiguously interlocks with the structure of said wearer's

outer ear auricle.

11. A system as defined in Claim 10 wherein said sound dampening means includes an external sound barrier portion

contiguous to said ear sealing surface portion.

12. A system as defined in Claim 11 wherein

said sound barrier portion is composed of barrier foam and has barrier surface membrane, and

said ear sealing surface portion has a sealing surface membrane.

13. A voice transmission system comprising:

a) eaφiece means having a structural configuration with an outer surface effective to removably interlock contiguously to the outer ear auricle of a wearer of the

eaφiece means, said eaφiece means includes a sound transmitting section removably secured to a sound dampening section,

b) first speaker means for sending inbound sounds and first microphone

means for receiving outbound voice sounds respectively to and from the tympanic mem¬ brane of said wearer, c) said first speaker means and first microphone means being structurally and

electrically connected to a circuit board member to form a speaker/microphone module, d) said circuit board member including means for electrically connecting and transmitting inbound electrical audio signals to the first speaker means and means for electrically connecting and transmitting outbound electrical voice signals from the first microphone means to control circuit means,

e) said control circuit means including outbound audio circuit means and inbound audio circuit means, said outbound audio circuit means being electrically connected to said first microphone means and said inbound audio circuit means being electrically connected to said first speaker means, f) second speaker means disposed at a location remote from said person for receiving said outbound electrical voice signals from the first microphone means, and g) second microphone means disposed at a location remote from said person for forwarding said inbound electrical audio signals to said first speaker means.

14. A system as defined in Claim 13 wherein said sound dampening section includes an external sound barrier portion contiguous to an ear sealing surface portion.

15. A system as defined in Claim 13 wherein said sound dampening section includes a surface recess having a shape and size sufficient to receive the sound transmitting section.

16. A system as defined in Claim 15 wherein

said surface recess includes means for removably mounting the sound

transmitting section to the sound dampening section.

17. A voice transmission system comprising:

a) eaφiece means including two separate and independent sound passageway

means having end ports open to respectively send and receive sounds directly to and from the tympanic membrane of a wearer of the eaφiece means,

b) control circuit means for alternately transmitting sound through one of the passageway means while the other passageway means is precluded from the transmission of sound,

c) said one of the passageway means being effective when open, to send

inbound sound from speaker means to cause modulation of the tympanic membrane of said wearer, d) said other passageway means being effective when open, to receive outbound voice sound caused by reverse modulation of the tympanic membrane of said

wearer, when speaking, for directing said voice sound to microphone means, e) said control circuit means, said speaker means and microphone means being located outside the eaφiece means, and f) means for disposing the speaker means and microphone means at a

location on the wearer's body away from the wearer's head.

18. A system as defined in Claim 17 wherein the eaφiece means includes a structural configuration with an outer surface

effective to removably interlock contiguously to the outer ear auricle of the wearer,

said structural configuration being effective to substantially eliminate audio

vibration pick-up of sound signals via bone and tissue conduction through the eaφiece means.

19. A system as defined in Claim 17 wherein said structural configuration includes a body portion and a canal extension

section projecting outwardly from the body portion into the external auditory canal of said wearer, said body portion being composed of a pliable material which substantially conforms to the ear surface profile of the wearer and forms a thin, flexible outer shell defining an inner sound attenuating chamber into which the two sound passageway means extend from their respective end ports.

20. A system as defined in Claim 17 wherein

each of the two sound passageway means includes a hollow flexible tube connected to a respective sound output means of the speaker means and sound input means of the microphone means.

21. A system as defined in Claim 17 wherein said control circuit means is disposed at a location remote from the eaφiece means and includes inbound audio circuit means to send electrical sound signals and

outbound audio circuit means connected to receive electrical voice sound signals, respec¬

tively, to the speaker means and from the microphone means.

22. A system as defined in Claim 21 wherein said microphone means and speaker means are structurally and electrically connected to a circuit board member within a speaker/microphone module, said outbound audio circuit means is electrically connected to the microphone means via the circuit board member and said inbound audio circuit means is electrically connected to the speaker means via the circuit board member.

23. A system as defined in Claim 22 wherein the speaker/microphone module is encapsulated in a solid sound-proofing material.

24. A system as defined in Claim 21 wherein said outbound audio circuit means includes amplifier means and processor

means, said amplifier means being effective to amplify an intelligible electrical audio signal to a preselected fixed level output gain for producing an increased gain audio

signal having a voice portion and a noise portion, said processor means being effective to separate the noise portion from the voice portion for producing a clear voice sound to be transmitted by second speaker means remotely located away from said wearer.

25. A system as defined in Claim 24 wherein the inbound audio circuit means is effective to send inbound electrical sound signals from remotely located second microphone means to the speaker means which is supported on the wearer's body away from the wearer's head for forwarding sounds to the external auditory canal of said wearer.

26. A system as defined in Claim 17 wherein said control circuit means includes outbound audio circuit means, inbound audio circuit means and switch means for alternately activating the outbound audio circuit means and inbound audio circuit means, the outbound audio circuit means being effective to receive electrical voice signals from microphone means which picks up outgoing voice sounds which are caused by the reverse modulation of the tympanic membrane and are obtained from the air within the external auditory canal of the wearer, the inbound audio circuit means being effective to send inbound electrical sound signals to speaker means for transmitting sound to the external auditory canal of said wearer of the eaφiece means.

27. A system as defined in Claim 26 wherein the outbound audio circuit means includes amplifier means and processor means, said amplifier means being effective to amplify an intelligible electrical audio signal to a preselected fixed level output gain for producing a predetermined audio signal having an increased gain, a voice portion and a noise portion, said processor means being effective to separate the noise portion from the voice portion for producing a clear voice sound to be transmitted by second speaker means disposed at a location remote from said wearer of the eaφiece means.

28. A system as defined in Claim 27 wherein the eaφiece means includes a structural configuration with an outer surface effective to removably interlock contiguously to the outer ear auricle of a wearer of the eaφiece means, said structural configuration further being effective to substantially eliminate audio vibration pick-up of sound signals via bone and tissue conduction when the ear¬

piece means is disposed in the ear of said wearer.

29. An eaφiece assembly for a voice transmission system, said assembly compris¬

ing: a) an eaφiece member having an outer surface effective to removably interlock contiguously to the outer ear auricle of a wearer of the eaφiece member, b) sound dampening means being effective to substantially eliminate audio vibration pickup of sound signals via bone conduction through the eaφiece member, c) said eaφiece member including a canal extension section having open end ports and a length sufficient to dispose the open end ports at a spaced distance from the tympanic membrane to form an enclosed canal air chamber in the external auditory canal of said wearer, d) one of said end ports open into a first sound passageway means to receive voice sounds produced by the reverse modulation of the tympanic membrane of said wearer and transmitted through the canal air chamber, and e) the other of said end ports being opened into a second sound passageway means to send sounds through the canal air chamber to the tympanic membrane, f) said sound dampening means including means located to isolate the canal extension section from the bone conduction of sound.

30. An assembly as defined in Claim 29 wherein control circuit means alternately causes transmission of sound through one of the sound passageway means while the other sound passageway means is closed to the transmission of sound.

31. An eaφiece assembly for a voice transmission system, said assembly compris¬

ing: a) an eaφiece member having a structural configuration with an outer surface effective to removably interlock contiguously to the outer ear auricle of a wearer of the eaφiece member, b) said structural configuration further being effective to substantially eliminate audio vibration pickup of sound signals via bone conduction through the eaφiece member, c) said eaφiece member including a canal extension section having open end ports and a length sufficient to dispose the open end ports at a spaced distance from the tympanic membrane to form an enclosed canal air chamber in the external auditory canal of said wearer, d) one of said end ports open into a first sound passageway means to receive voice sounds produced by the reverse modulation of the tympanic membrane of said wearer and transmitted through the canal air chamber, and e) the other of said end ports being opened into a second sound passageway means to send sounds through the canal air chamber to the tympanic membrane,

f) said eaφiece member includes a speaker/microphone module which is encapsulated in a rigid material.

32. An assembly as defined in Claim 31 wherein said module includes first speaker means and first microphone means structurally and electrically connected to a circuit board member.

33. An eaφiece assembly for a voice transmission system, said assembly compris¬ ing: a) an eaφiece member having a structural configuration with an outer surface effective to removably interlock contiguously to the outer ear auricle of a wearer of the eaφiece member, b) said structural configuration further being effective to substantially eliminate audio vibration pickup of sound signals via bone conduction through the eaφiece member, c) said eaφiece member including a canal extension section having open end ports and a length sufficient to dispose the open end ports at a spaced distance from the tympanic membrane to form an enclosed canal air chamber in the external auditory canal of said wearer, d) one of said end ports opens into a first sound passageway means to receive voice sounds produced by the reverse modulation of the tympanic membrane of said wearer and transmitted through the canal air chamber, e) the other of said end ports being opened into a second sound passageway means which delivers sounds to be transmitted through the canal air chamber to the

tympanic membrane, f) first speaker means which sends inbound sounds to the tympanic mem¬ brane via second sound passageway means, and g) first microphone means which receives outbound voice sounds via said first sound passageway means from the canal air chamber caused by reverse modulation of the tympanic membrane of said wearer, h) said first speaker means and first microphone means are structurally and electrically connected to a circuit board member within a speaker/microphone module which is disposed at a location outside the eaφiece member.

34. An assembly as defined in Claim 33 wherein said module is mounted to means for locating the module on the wearer's body away from the wearer's head, said structural configuration includes a body portion composed of a pliable material which substantially conforms to the ear surface profile of the wearer and forms a thin, flexible shell defining an inner sound attenuating chamber through which the first and second sound passageway means extend to respective sound outlet and inlet ports of the first speaker means and first microphone means.

35. An assembly as defined in Claim 29 wherein each of the two sound passageway means includes a hollow flexible tube connected to a respective sound outlet port of the speaker means and a sound inlet port of the microphone means.

36. A control circuit for a voice transmission system, said circuit comprising: a) outbound audio circuit means, inbound audio circuit means and switch means for alternately activating the outbound audio circuit means and inbound audio circuit means, b) the outbound audio circuit means being effective to receive electrical voice signals from first microphone means which picks up outgoing voice sounds produced by reverse modulation of the tympanic membrane and obtained from the air within the exter¬ nal auditory canal of a person, c) the inbound audio circuit means being effective to send inbound electrical sound signals from second microphone means to first speaker means which sends sound into the external auditory canal to said tympanic membrane, d) the outbound audio circuit means including amplifier means and processor means, e) said amplifier means being effective to amplify an intelligible electrical audio signal to a preselected fixed level output gain for producing an increased gain audio signal having a voice portion and a noise portion, f) said processor means being effective to separate the noise portion from the voice portion for producing a clear voice sound to be transmitted by second speaker

means disposed at a location remote from said person.

37. A control circuit as defined in Claim 36 wherein

said amplifier means includes buffer means to produce a balanced impedance

in the outbound electrical voice signal before entering the processor means.

38. A control circuit as defined in Claim 36 wherein said outbound audio circuit means includes capacitive means for removing a preselected lower frequency portion from the outbound electrical voice signal before entering said amplifier means.

39. A control circuit as defined in Claim 36 wherein

said processor means includes a comparator for directing the faster rate of change of frequency of an electrical voice signal to the second speaker means and

directing the slower rate of change of frequency of an electrical noise signal to ground.

40. A method of communicating to a remote location a person's outgoing voice sounds caused by reverse modulation of the tympanic membrane when said person

speaks, said method comprising:

a) providing means for picking up said voice sounds substantially exclusively from the air within the external auditory canal of the person, b) isolating the means for picking up said voice sounds for substantially eliminating audio vibration pickup of sound transmitted by bone and tissue conduction, c) converting the voice sounds to amplified electrical voice signals without a noise portion, and d) directing the amplified electrical voice signals to speaker means for transmitting a clear voice sound of said person at the remote location.

41. A method of communicating to a remote location a person's outgoing voice sounds caused by reverse modulation of the tympanic membrane when said person speaks, said method comprising: a) picking up said voice sounds substantially exclusively from the air within the external auditory canal of the person while substantially eliminating audio vibration pickup of sound transmitted by bone and tissue conduction, b) converting the voice sounds to amplified electrical voice signals without a noise portion, and c) directing the amplified electrical voice signals to speaker means for transmitting a clear voice sound of said person to the remote location, d) said picking up step includes forming an enclosed air chamber within the

external auditory canal, e) said audio vibration eliminating step includes forming an inner sound attenuating chamber within a thin, flexible outer shell composed of pliable material which

substantially conforms to the ear wall surface profile of the person and is effective to

dampen sound vibration from the ear wall surface into the inner sound attenuating

chamber,

f) said audio picking up step further includes directing said voice sounds from the air chamber through the inner attenuating chamber and to a sound inlet port of microphone means disposed at a location remote from the person's ear.

42. A method of communicating to a remote location a person's outgoing voice

sounds caused by reverse modulation of the tympanic membrane when said person speaks, said method comprising:

a) picking up said voice sounds substantially exclusively from the air within the external auditory canal of the person while substantially eliminating audio vibration pickup of sound transmitted by bone and tissue conduction, b) converting the voice sounds to amplified electrical voice signals without a noise portion, and c) directing the amplified electrical voice signals to speaker means for

transmitting a clear voice sound of said person to the remote location, d) said voice sounds converting step includes forming outbound electrical

voice signals from the outgoing voice sounds, eliminating a low frequency portion from the outgoing electrical signals to produce intelligible electrical audio signals, amplifying the intelligible audio signals to a preselected fixed level output gain to produce a prede¬ termined increased gain electrical audio signal, processing the increased gain audio signal to separate the noise portion from the electrical audio signal, and transmitting the voice

portion electrical signal to speaker means at the remote location.

43. A communication assembly for transmitting outgoing voice sounds caused by reverse modulation of the tympanic membrane of a person who is speaking, said assembly comprising: a) means for picking up the outgoing voice sounds substantially exclusively from the air within the external auditory canal of the person speaking while substantially eliminating the audio vibration pickup of sound transmitted by bone conduction, b) said voice sounds picking up means including sound dampening means and sound transmitting eaφiece means having an outer shell composed of pliable material which substantially conforms to the ear wall surface profile of the person, and said sound dampening means being effective to dampen sound vibration from the ear wall surface into the sound transmitting eaφiece means, c) said sound transmitting eaφiece means including a canal extension section having an outer surface spaced inwardly from the wall of the external auditory canal and including an open end port disposed a spaced distance from the tympanic member when the sound transmitting eaφiece means is contiguously interlocked with the outer ear auricle of said person, d) said sound dampening means including means disposed between the auditory canal wall and the outer surface of the canal extension section to isolate the extension section from bone conduction of sound, and e) means for directing the outgoing voice sounds from the open end port to an inlet sound port of microphone means.

44. An assembly as defined in Claim 43 wherein said dampening means includes annular means disposed around the canal extension section, said dampening means being composed of material effective to seal an enclosed air chamber between the extension section end port and the tympanic membrane.

45. An assembly as defined in Claim 43 wherein said microphone means is disposed at a location remote from the sound transmitting eaφiece means.

46. An assembly as defined in Claim 43 wherein

said outgoing voice sound directing means includes a flexible tube member with the open end port at one end thereof and being connected at the other end thereof to

the inlet sound port.

47. An assembly as defined in Claim 43 wherein said outer shell defines an inner sound attenuating chamber, and

sound attenuating filler means is disposed in the inner sound attenuating chamber to dampen audio vibration pickup of sound waves to the outgoing voice sounds directing means.

48. An assembly as defined in Claim 43 wherein two open end ports are located in the canal extension section and a flexible tube member extends from each end port through the inner sound attenuating chamber to respective sound inlet and sound outlet ports of microphone means and speaker means.

49. An assembly as defined in Claim 48 wherein the microphone means and speaker means are structurally and electrically connected to a circuit board member which electrically connects said microphone means and said speaker means to control circuit means.

50. An assembly as defined in Claim 49 wherein said microphone means and said speaker means forms a module which is encapsulated in rigid material, and means dispose said encapsulated module at a location on an assembly user's

body remote from the user's head.

51. A voice transmission assembly for communicating to a remote location a pers¬ on's outgoing voice sounds caused by reverse modulation of the tympanic membrane

when said person speaks, said assembly comprising: a) means for picking up said voice sounds substantially exclusively from the air within the external auditory canal of the person, b) means for isolating the means for picking up said voice sounds for substantially eliminating audio vibration pickup of sound transmitted by bone and tissue conduction, c) means for converting the voice sounds to amplified electrical voice signals without a noise portion, and d) means for directing the amplified electrical voice signals to speaker means for transmitting a clear voice sound of said person at the remote location.

52. An assembly as defined in Claim 51 wherein said isolating means includes a thin, flexible outer shell composed of pliable material which substantially conforms to the ear wall surface profile of the person and is effective to dampen sound vibration from the ear wall surface of bone and tissue, said voice sounds picking up means includes means for directing said voice

sounds from the air chamber to a sound inlet port of a microphone means.

53. An assembly as defined in Claim 51 wherein said voice sounds converting means includes means for forming outbound electrical voice signals from the outgoing voice sounds, means for eliminating a low

frequency portion from the outgoing electrical signals to produce intelligible electrical audio signals, means for amplifying the intelligible audio signals to a preselected fixed level output gain to produce a predetermined increased gain electrical audio signal, means for processing the increased gain audio signal to separate the noise portion from the electrical audio signal, and means for transmitting the voice portion electrical signal to speaker means at the remote location.

54. An assembly as defined in Claim 51, wherein said means for picking up said voice sounds includes eaφiece means for disposing an open end port a spaced distance from the tympanic member when the eaφiece means is contiguously interlocked with the outer ear auricle of said person, said isolating means includes dampening means for attenuating audio vibration pickup of sound transmitted by bone and tissue conduction to the open end port.

55. An assembly as defined in Claim 54, wherein said dampening means is effective to seal an enclosed air chamber between

the open end port and the tympanic membrane.

56. An assembly as defined in Claim 54, wherein

said eaφiece means includes canal extension means having an outer surface spaced inwardly from the wall of the external auditory canal of the person speaking, and

the dampening means is disposed between the auditory canal wall and the

outer surface of the canal extension means.

57. A method of transmitting voice sound from an ear canal, said method comprising: a) sensing voice sound at a first location within an ear canal, b) said voice sound having a voice component and a noise component,

c) sensing a noise sound sample at location spaced from said first location,

d) opposing the voice sound with the noise sound sample to substantially eliminate the noise component from the noise sound thereby producing a resultant substantially noise free voice sound, and e) transmitting the resultant voice sound to a third location.

58. A method as defined in Claim 57 wherein

said voice sound sensing step includes disposing a mechanical diaphragm within the ear canal to define a noise sampling chamber on one side thereof and a voice

sound chamber on the other side thereof,

sensing the pressure difference between noise pressure in the noise sampling chamber and sound pressure in the voice sound chamber, transmitting said pressure difference to an audio signal output.

59. A method as defined in Claim 57 wherein

the step of sensing the noise sound sample takes place at a second location

within the ear canal, said second location being sound insulated from said first location.

60. A method as defined in Claim 57 wherein the voice sound sensing step includes converting the voice sound into an electrical voice sound signal, the noise sound sample sensing step includes converting the noise sound sample into an electrical noise sound signal, and

the voice sound opposing step includes electrically opposing the electrical voice and noise sound sample signals to produce a resultant electrical substantially noise-

free voice sound signal.

61. A method as defined in Claim 60 wherein the voice sound converting step takes place within the ear canal.

62. A method as defined in Claim 61 wherein the noise sound sample converting step takes place within the ear canal.

63. A method as defined in Claim 57 wherein

the noise sound sample location is within the ear canal and sound insulated from said first location, said sensing steps includes converting the voice sound and noise sound sample into respective electrical voice sound and noise sound signals, and electrically opposing the voice sound and noise sound sample signals to substantially eliminate the noise component from the voice sound signal.

64. A method as defined in Claim 63 wherein said sound converting step is effected at a location outside the ear canal.

65. An eaφiece assembly comprising: a) an eaφiece projection having a structural configuration effective for disposition within an ear canal of a person wearing the assembly, b) said eaφiece projection including means for picking up voice sounds within an ear canal, insulation means disposed to define a noise sampling chamber within the ear canal, and means for picking up a noise sample sound within the noise sampling

chamber, c) means for converting the voice sounds and noise sample sounds into respective electrical voice sound signals and noise sample sound signals, d) said electrical voice sound signals having a noise portion and a sound portion, e) circuit means for receiving the electrical voice sound signals and noise sample sound signals to produce a resultant differential voice signal having said noise portion substantially effectively removed, and f) means for transmitting said resultant differential voice signal to another location remote from said assembly.

66. An assembly as defined in Claim 65 wherein the sound to electrical signal converting means is located within the eaφiece projection.

67. An assembly as defined in Claim 65 wherein the sound to electrical signal converting means is located outside the eaφiece projection, and said sound picking-up means includes tubing means for carrying sound from the eaφiece projection to said electrical signal converting means.

68. An assembly as defined in Claim 65 including means for directing inbound voice sounds into the eaφiece projection to the tympanic membrane to enable two-way communication within the ear canal.

69. In a voice transmission system having an eaφiece for effecting two-way communication within the ear canal of a person wearing the eaφiece, the combination comprising: a) first pickup means for receiving voice audio sound from within the ear canal of the eaφiece wearer, b) second pickup means for receiving a cancelling noise sound, c) microphone means for converting the voice audio sound and the cancelling noise sound into a respective voice audio electrical signal and cancelling noise electrical signal, d) first electrical signal processing means for equalizing the phase and amplitude of the voice audio electrical signal and the cancelling noise electrical signal, and e) second electrical signal processing means for electrically aligning the cancelling noise electrical signal and voice audio electrical signal after being equalized to oppose each other 180 degrees out of phase thereby producing a resultant substantially noise-free voice signal.

70. The combination as defined in Claim 69 wherein

the microphone means is disposed in an eaφiece projection having a structural

configuration to fit within the ear canal of the person wearing the eaφiece.

71. The combination as defined in Claim 69 wherein the voice transmission system includes sound dampening means disposed to isolate the eaφiece when the eaφiece is removably interlocked contiguously to the outer ear auricle of the person wearing it for thereby substantially eliminating audio vibration pickup of sound transmitted by bone and tissue conduction.

72. The combination as defined in Claim 69 wherein the microphone means includes first microphone means for converting the voice audio sound into a voice audio electrical signal and second microphone means for converting the cancelling noise sound into a cancelling noise electrical signal, and the voice transmission system includes a tubular sound carrier connected to speaker means for directing inbound sound through the eaφiece to a location within the ear canal adjacent the person's tympanic membrane.