USH417H
Expired / Lapsed
US
⏱️ 0.0 years remaining
Headset for ambient noise suppression
Assignee: United States Department of the Air Force
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Filing: 1987-03-05
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Granted: 1988-01-05
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Expires: 2007-03-05
Abstract
Abstract The headset system utilizes the theory that unique sound waves can be added or subtracted without loss of information to attenuate the noise at the ear and mouthpiece, without lowering the noise level of the environment. This allows for clearer reception and transmission of communication. The system includes a directional microphone mounted on a headset/helmet, isolated from both voice and earphone output, level-setting and frequency tailoring circuits, and voltage summers and amplifiers. The microphone picks up the ambient noise, and the level-setting and frequency tailoring circuits produce a close approximation of the noise at the ear and mouthpiece (i.e., two separate matching circuits). This signal is then inverted (using an inverting buffer) to provide destructive interference.
Inventors
- 👤 Michael W. Miles
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-29 06:28
CPC Classifications
H; H04; H04R; H04R3/00; H04R3/005; G; G10; G10K; G10K11/00; G10K11/16; G10K11/175; G10K11/178; G10K11/1785; G10K11/17853; G10K11/17857; G10K11/1787; G10K11/17873; G10K11/17885; G10K2210/00; G10K2210/10; G10K2210/108; G10K2210/1081; G10K2210/1082; G10K2210/30; G10K2210/301; G10K2210/3011; G10K2210/3013; G10K2210/3028
Claims Analysis
Total Claims: 4
Claim 1
Independent Claim
167 words
A headgear system for noise cancellation which utilizes the theory that unique sound waves can be added or subtracted without loss of information, comprising a directional noise microphone mounted on headgear, isolated from both voice and earphone output, a receiving destructive interference unit and a separate sending destructive interference unit, each of which includes signal conditioning means in tandem with phase inverting means, the receiving destructive interference unit having an input coupled to the noise microphone and an output coupled to receiving summing means, the sending destructive interference unit having an input coupled to the noise microphone and an output coupled to a sending summing means, with each signal conditioning means comprising level-setting and frequency tailoring circuits, the receiving summing means having another input coupled to a line for receiving voice signals and an output coupled to earphone means of the headgear, the sending summing means having another input coupled to a communication microphone of the headgear and an output to a line for sending voice signals.
Claim 2
Dependent Claim
167 words
A headgear system for noise cancellation which utilizes the theory that unique sound waves can be added or subtracted without loss of information, comprising a directional noise microphone mounted on headgear, isolated from both voice and earphone output, a receiving destructive interference unit and a separate sending destructive interference unit, each of which includes signal conditioning means in tandem with phase inverting means, the receiving destructive interference unit having an input coupled to the noise microphone and an output coupled to receiving summing means, the sending destructive interference unit having an input coupled to the noise microphone and an output coupled to a sending summing means, with each signal conditioning means comprising level-setting and frequency tailoring circuits, the receiving summing means having another input coupled to a line for receiving voice signals and an output coupled to earphone means of the headgear, the sending summing means having another input coupled to a communication microphone of the headgear and an output to a line for sending voice signals.
Claim 3
Dependent Claim
263 words
A headgear system for noise cancellation which utilizes the theory that unique sound waves can be added or subtracted without loss of information, comprising a directional noise microphone mounted on headgear, isolated from both voice and earphone output, to pick up the ambient noise, a noise pre-amplifier coupled to the noise microphone, a receiving filter/amplifier matching circuit and a separate sending filter/amplifier matching circuit, each having a level-setting amplifier coupled to an output of the noise pre-amplifier followed by a frequency and time-tailoring filter circuit, to produce a close approximation of the noise at the ear and mouthpiece, respectively; a receiving inverting buffer coupled to an output of the receiving filter/amplifier circuit for inverting the phase to provide destructive interference, an output of the receiving inverting buffer being supplied as one input to a receiving summing amplifier, a voice input signal on a receive line being supplied as another input of the receiving summing amplifier, and the output of the receiving summing amplifier being supplied via an amplification stage to the earphone, to effectively cancel noise at the earpiece; a sending inverting buffer coupled to an output of the sending filter/amplifier circuit for inverting the phase to provide destructive interference, an output of the sending inverting buffer being supplied as one input to a sending summing amplifier, a voice signal from a communication microphone in the headgear being supplied via a pre-amplifier to another input of the sending summing amplifier, and the added signal output from the sending summing amplifier being supplied to a transmit line to effectively cancel noise at the mouthpiece.
Claim 4
Dependent Claim
263 words
A headgear system for noise cancellation which utilizes the theory that unique sound waves can be added or subtracted without loss of information, comprising a directional noise microphone mounted on headgear, isolated from both voice and earphone output, to pick up the ambient noise, a noise pre-amplifier coupled to the noise microphone, a receiving filter/amplifier matching circuit and a separate sending filter/amplifier matching circuit, each having a level-setting amplifier coupled to an output of the noise pre-amplifier followed by a frequency and time-tailoring filter circuit, to produce a close approximation of the noise at the ear and mouthpiece, respectively; a receiving inverting buffer coupled to an output of the receiving filter/amplifier circuit for inverting the phase to provide destructive interference, an output of the receiving inverting buffer being supplied as one input to a receiving summing amplifier, a voice input signal on a receive line being supplied as another input of the receiving summing amplifier, and the output of the receiving summing amplifier being supplied via an amplification stage to the earphone, to effectively cancel noise at the earpiece; a sending inverting buffer coupled to an output of the sending filter/amplifier circuit for inverting the phase to provide destructive interference, an output of the sending inverting buffer being supplied as one input to a sending summing amplifier, a voice signal from a communication microphone in the headgear being supplied via a pre-amplifier to another input of the sending summing amplifier, and the added signal output from the sending summing amplifier being supplied to a transmit line to effectively cancel noise at the mouthpiece.
References Cited (Backward Citations)
No citation records indexed.
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1991-01-04 | 1991-07-06 | 1992-01-05 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1995-01-04 | 1995-07-06 | 1996-01-05 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1999-01-04 | 1999-07-06 | 2000-01-05 | $7700.00 | Window Closed / Lapsed |