Patent US4661981A successfully refreshed from Google Patents.
US4661981A
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Method and means for processing speech
Assignee: Individual
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Filing: 1985-09-20
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Granted: 1987-04-28
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Expires: 2005-09-20
Abstract
Abstract A method of and apparatus for processing audio signals in which a measure of amplitude of audio signals in a selected time period is obtained. The audio signals for the selected time period are delayed until the measure of amplitude is obtained, and then the delayed audio signals are normalized using the measure of amplitude. High-frequency emphasis may be employed prior to obtaining the measure of amplitude. Alternatively, a multi-channel system can be employed for processing audio signals in limited frequency bands. The method and apparatus are applicable in a variety of applications including hearing aids, audio storage media, broadcast and public address systems, and voice communications such as telephone systems.
Inventors
- 👤 Larry K. Henrickson
- 👤 Dorothy A. Huntington
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-31 13:16
CPC Classifications
H; H03; H03G; H03G7/00; H03G7/002; H03G9/00; H03G9/02; H03G9/025; H04; H04R; H04R2225/00; H04R2225/43; H04R25/00; H04R25/35; H04R25/356
Claims Analysis
Total Claims: 2
Claim 1
Independent Claim
188 words
Apparatus for enhancing speech comprising microphone means for receiving audio signals and generating electrical signals in response thereto, high-frequency emphasis means connected to said microphone means for amplifying said electrical signals and providing spectrally shaped electrical signals, amplitude detection means connected to said high-frequency emphasis means for receiving said spectrally shaped electrical signals and obtaining a root-mean-square (RMS) amplitude of said spectraly shaped electrical signals over a selected period of time corresponding approximately to a glottal period of speech, delay means connected to said high-frequency emphasis means for receiving and delaying said spectrally shaped electrical signals for said selected period of time corresponding approximately to a glottal period of speech, and signal compression means connected to said delay means and to said amplitude detection means and including divider means for dividing a delayed spectrally shaped electrical signal by the root-mean-square amplitude of said delayed spectrally shaped electrical signal and thereby compressing the delayed spectrally shaped electrical signal by a ratio of at least 10:1 in accordance with said root-mean-square average value whereby a constant amplitude output signal without significant signal distortion is obtained for each segment of speech.
Claim 2
Dependent Claim
188 words
Apparatus for enhancing speech comprising microphone means for receiving audio signals and generating electrical signals in response thereto, high-frequency emphasis means connected to said microphone means for amplifying said electrical signals and providing spectrally shaped electrical signals, amplitude detection means connected to said high-frequency emphasis means for receiving said spectrally shaped electrical signals and obtaining a root-mean-square (RMS) amplitude of said spectraly shaped electrical signals over a selected period of time corresponding approximately to a glottal period of speech, delay means connected to said high-frequency emphasis means for receiving and delaying said spectrally shaped electrical signals for said selected period of time corresponding approximately to a glottal period of speech, and signal compression means connected to said delay means and to said amplitude detection means and including divider means for dividing a delayed spectrally shaped electrical signal by the root-mean-square amplitude of said delayed spectrally shaped electrical signal and thereby compressing the delayed spectrally shaped electrical signal by a ratio of at least 10:1 in accordance with said root-mean-square average value whereby a constant amplitude output signal without significant signal distortion is obtained for each segment of speech.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1990-04-27 | 1990-10-27 | 1991-04-28 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1994-04-27 | 1994-10-27 | 1995-04-28 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1998-04-27 | 1998-10-27 | 1999-04-28 | $7700.00 | Window Closed / Lapsed |