Patent US3553372A successfully refreshed from Google Patents.
US3553372A
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Speech recognition apparatus
Assignee: International Standard Electric Corp
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Filing: 1966-10-18
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Granted: 1971-01-05
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Expires: 1986-10-18
Abstract
Abstract Speech recognition is effected by zero crossing analysis of the speech waveform wherein the time interval between consecutive zero crossings is measured, with these intervals and combinations thereof being subsequently identified. Measurement of the intervals is based on a nonlinear timescale, the rate of generation of which is dependent on the fundamental frequency of the speaker. Alterations in the timescale generation are effected due to the initial time constant of the timescale generator circuitry being proportional to and controlled by the variations in the fundamental frequency of the speech waveform.
Inventors
- 👤 Esmond Philip Goodwin Wright
- 👤 Wincenty Bezdel
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-24 03:56
CPC Classifications
G; G10; G10L; G10L25/00; G10L25/90
Claims Analysis
Total Claims: 3
Claim 1
Independent Claim
117 words
Speech recognition apparatus comprising: a. a speech waveform source; b. means coupled to said speech waveform source for detecting waveform reversals of plurality and generating therefrom a corresponding output waveform; c. means coupled to said speech waveform source for detecting the waveform fundamental frequency and generating therefrom a voltage representative of said fUndamental frequency; d. means, responsive to said reversal detector and to said fundamental frequency detector, for generating a nonlinear measuring timescale waveform, said nonlinear timescale being initiated whenever a reversal is detected and altered according to variations in the fundamental frequency; and e. means, coupled to said reversal detector and to said timescale generator for counting the number of timescale units generated between detected reversals.
Claim 2
Dependent Claim
117 words
Speech recognition apparatus comprising: a. a speech waveform source; b. means coupled to said speech waveform source for detecting waveform reversals of plurality and generating therefrom a corresponding output waveform; c. means coupled to said speech waveform source for detecting the waveform fundamental frequency and generating therefrom a voltage representative of said fUndamental frequency; d. means, responsive to said reversal detector and to said fundamental frequency detector, for generating a nonlinear measuring timescale waveform, said nonlinear timescale being initiated whenever a reversal is detected and altered according to variations in the fundamental frequency; and e. means, coupled to said reversal detector and to said timescale generator for counting the number of timescale units generated between detected reversals.
Claim 3
Dependent Claim
78 words
Apparatus according to claim 1 in which the means for generating the nonlinear time scale includes first and second transistors having complementary symmetry with their emitters connected together, a positive feedback connection between the base of the first transistor and the collector of the second transistor, first and second capacitors connected to the base of the second transistor and means for charging the first and second capacitors at differential rates by the voltage related to the fundamental frequency.
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) | 1974-01-04 | 1974-07-06 | 1975-01-05 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1978-01-04 | 1978-07-06 | 1979-01-05 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1982-01-04 | 1982-07-06 | 1983-01-05 | $7700.00 | Window Closed / Lapsed |