Voice transmission system and method for high ambient noise conditions

• US 5,327,506 A
• Filed: 05/03/1993
• Issued: 07/05/1994
• Est. Priority Date: 04/05/1990
• Status: Expired due to Fees

• Current Assignee: George M. Stites III
• Original Assignee: George M. Stites III
• Inventors: Stites, George M. III
• Primary Examiner(s): Kuntz, Curtis
• Assistant Examiner(s): TRAN, SINH N
• Application Number:
  US08/055,378
• Time in Patent Office: 428 Days
• Field of Search: 381/94, 381/72, 381/71, 381/151, 381/169
• US Class Current: 381/355
• CPC Class Codes: H04B 1/38 Transceivers, i.e. devices in which transmitter and receiver form a structural unit and in which at least one part is used for functions of transmitting and receiving
• CPC Class Codes: H04B 1/385 Transceivers carried on the body, e.g. in helmets
• CPC Class Codes: H04B 2001/3866 carried on the head
• CPC Class Codes: H04M 1/6041 Portable telephones adapted for handsfree use
• CPC Class Codes: H04R 1/08 Mouthpieces; Microphones; Attachments therefor
• CPC Class Codes: H04R 2225/43 Signal processing in hearing aids to enhance the speech intelligibility
• CPC Class Codes: H04R 2460/13 Hearing devices using bone conduction transducers
• CPC Class Codes: H04R 25/43 Electronic input selection or mixing based on input signal analysis, e.g. mixing or selection between microphone and telecoil or between microphones with different directivity characteristics H04R25/407 takes precedence
• CPC Class Codes: H04R 25/652 Ear tips; Ear moulds hybrid ear moulds or post-processing thereof for their customisation H04R25/659
• CPC Class Codes: H04R 25/658 Manufacture of housing parts

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. Specific features of the invention are directed to a two-way communication system, the structure of a speaker/microphone module, the structural configuration of an earpiece assembly, specific control circuitry, and a particular assembly for conducting a method of communicating voice sounds substantially exclusively from the air of the external auditory canal while substantially eliminating audio vibration pickup of sound signals by bone conduction. The voice transmission system and method effect intelligible voice communication in an environment having ambient noise at a level greater than 90 decibels.

Claims

1. A control circuit for a voice transmission system including an earpiece member having a structural configuration with an outer surface effective to removably interlock contiguously to the outer ear auricle of a wearer of the earpiece member, said earpiece member including a canal extension with means for receiving outbound voice sounds within the ear canal and means for sending inbound sounds to the ear canal, 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 outbound electrical voice signals from first microphone means which picks up outgoing voice sounds from said means for receiving outbound voice sounds produced by reverse modulation of the tympanic membrane and obtained from the air within the external 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 sounds into the external auditory canal to said tympanic membrane through said means for sending inbound sounds,

d) the outbound audio circuit means including amplifier means and processor means,

e) said amplifier means being effective to amplify intelligible said electrical voice signals said to a preselected fixed level output gain for producing increased gain audio signals each 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.

2. A control circuit as defined in claim 1 wherein

said amplifier means includes buffer means to produce a balanced impedance in the outbound electrical voice signals before entering the processor means.

3. 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 external 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 sounds 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 intelligible said electrical voice signals to a preselected fixed level output gain for producing increased gain audio signals each 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,

g) said outbound audio circuit means further includes capacitive means for removing a preselected lower frequency portion from the outbound electrical voice signals before entering said amplifier means.

4. 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 external 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 sounds 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 intelligible said electrical voice signal to a preselected fixed level output gain for producing increased gain audio signals each 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,

g) said processor means further includes a comparator for directing a faster rate of change of frequency of an electrical voice signal from said voice portion to the second speaker means and directing a slower rate of change of frequency of an electrical noise from said noise portion signal to ground.

5. A method of transmitting voice sound from within an ear canal, said method comprising:

a) locating a voice sound sensing means at a first location and sensing voice sound at the first location within said ear canal,

b) said voice sound having a voice component and a noise component,

c) sensing a noise sound sample at a second 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 noise free voice sound to a third location.

6. A method as defined in claim 5 wherein

said step of sensing voice sound 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, and

transmitting said pressure difference to an audio signal output.

7. A method as defined in claim 5 wherein

the second location is within the ear canal and is sound insulated from said first location.

8. A method as defined in claim 5 wherein

the step of sensing voice sound includes converting the voice sound into an electrical voice sound signal,

the step of sensing a noise sound sample includes converting the noise sound sample into an electrical noise sound signal, and

the step of opposing the voice sound with the noise sound sample includes electrically opposing the electrical voice sound signal with the electrical noise sound signal to produce a resultant electrical substantially noise-free voice sound signal.

9. A method as defined in claim 8 wherein

the step of converting the voice sound takes place within the ear canal.

10. A method as defined in claim 9 wherein

the step of converting the noise sound sample takes place within the ear canal.

11. A method as defined in claim 5 wherein

the second location at which the noise sound is sampled is within the ear canal and sound insulated from said first location,

said sensing steps includes a sound converting step, said comprising converting the voice sound and noise sound sample into respective electrical voice sound and noise sound signals, and

electrically opposing the electrical voice sound and noise sound signals to substantially eliminate the noise component from the voice sound signal.

12. A method as defined in claim 11 wherein

said sound converting step is effected at a location outside the ear canal.

13. An earpiece assembly comprising:

a) an earpiece projection having a structural configuration effective for disposition within an ear canal of a person wearing the assembly,

b) said earpiece projection including first sound receiving means for picking up within a voice sound chamber in said ear canal voice sounds produced by the tympanic membrane of said person, insulation means disposed adjacent the voice sound chamber to define a noise sampling chamber within the ear canal, and second sound receiving means for picking up noise sample sounds within the noise sampling chamber,

c) transducer 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.

14. An assembly as defined in claim 13 wherein

the transducer means is located within the earpiece projection.

15. An assembly as defined in claim 13 wherein

the transducer means is located outside the earpiece projection, and

said first and second sound receiving means include tubing means for carrying sound from the earpiece projection to said transducer means.

16. An assembly as defined in claim 13 wherein

said earpiece projection further includes means for directing inbound voice sounds into the ear canal through the earpiece projection to the tympanic membrane thereby enabling two-way sound communication within the ear canal.

17. In a voice transmission system having an earpiece for effecting two-way communication within the ear canal of a person wearing the earpiece wherein the earpiece has an earpiece projection, the combination comprising:

a) first pickup means for receiving voice audio sound from within the ear canal of the earpiece 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,

f) said microphone means is disposed in the earpiece projection having a structural configuration to fit within the ear canal of the person wearing the earpiece.

18. The combination as defined in claim 17 wherein

the voice transmission system further includes sound dampening means disposed to isolate the earpiece when the earpiece 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.

19. The combination as defined in claim 17 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 further includes a tubular sound carrier connected to speaker means for directing inbound sound through the earpiece to a location within the ear canal adjacent the person'"'"'s tympanic membrane.