Patent US3617636A successfully refreshed from Google Patents.
US3617636A
Expired / Lapsed
US
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Pitch detection apparatus
Assignee: NEC Corp
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Filing: 1969-09-22
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Granted: 1971-11-02
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Expires: 1989-09-22
Abstract
Abstract Pitch detection apparatus is disclosed in accordance with the teachings of the present invention wherein a double-pitch signal is eliminated by dividing an input speech into a plurality of frequency domains of discrete frequency ranges. The pitch frequency of the speech signal is detected and pitch pulses representative thereof are produced and combined with the frequency domains to suppress certain ones of said pulses corresponding to the double-pitch signal.
Inventors
- 👤 Takashi Ogihara
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-31 10:45
CPC Classifications
G; G10; G10L; G10L25/00; G10L25/90
Claims Analysis
Total Claims: 17
Claim 1
Independent Claim
129 words
Pitch detection apparatus comprising: first means adapted to receive a speech signal whose pitch is to be determined; second means coupled to said first means for generating indications of the pitch frequency of said speech signal and of the double-pitch frequency of said speech signal; third means coupled to said first means for separating said speech signal into a plurality of frequency domains of discrete frequency ranges to detect an indication of a fundamental frequency of said speech signal; and fourth means coupled to said second and said third means for comparing said pitch and said double-pitch frequency indications with said fundamental frequency indication to inhibit said double-pitch indication in an output of said fourth means when said pitch and said double-pitch frequency indications exceed said fundamental frequency indication.
Claim 2
Dependent Claim
129 words
Pitch detection apparatus comprising: first means adapted to receive a speech signal whose pitch is to be determined; second means coupled to said first means for generating indications of the pitch frequency of said speech signal and of the double-pitch frequency of said speech signal; third means coupled to said first means for separating said speech signal into a plurality of frequency domains of discrete frequency ranges to detect an indication of a fundamental frequency of said speech signal; and fourth means coupled to said second and said third means for comparing said pitch and said double-pitch frequency indications with said fundamental frequency indication to inhibit said double-pitch indication in an output of said fourth means when said pitch and said double-pitch frequency indications exceed said fundamental frequency indication.
Claim 3
Dependent Claim
55 words
The pitch detection apparatus of claim 1 wherein said third means comprises a plurality of filter means, each having an input coupled to said first means and including an output; and pulse generating means having an input coupled to said filter means outputs and including an output connected to an input of said fourth means.
Claim 4
Dependent Claim
43 words
The pitch detection apparatus of claim 2 wherein said fourth means comprises gate means having an input constituting said fourth means input connected to said pulse generating means output said gate means including another input connected to an output of said second means.
Claim 5
Dependent Claim
44 words
The pitch detection apparatus of claim 3 wherein said pulse generating means comprises a plurality of pulse generators each producing a pulse having a duration corresponding to one of said frequency ranges, and each coupled to said output of one of said filter means.
Claim 6
Dependent Claim
56 words
The pitch detection apparatus of claim 4 wherein said pulse generators comprise monostable multivibrators and said gate mans comprises an OR-gate coupled to each of said monostable multivibrators, said OR-gate having an output coupled to an input of a coincidence gate, said coincidence gate having a further input coupled to said output of said second means.
Claim 7
Dependent Claim
35 words
The pitch detection apparatus of claim 5 wherein said monostable multivibrators are coupled to said output of each of said filter means by a plurality of AND-gates, said AND-gates being activated by said second means.
Claim 8
Dependent Claim
17 words
The pitch detection apparatus of claim 6 wherein said second means comprises envelope emphasis pitch detection means.
Claim 9
Dependent Claim
16 words
The pitch detection apparatus of claim 6 wherein said second mEans comprises autocorrelation pitch detection means.
Claim 10
Dependent Claim
91 words
Apparatus for eliminating indications of double pitch which may be produced in a speech analysis system comprising; first means responsive to a speech signal for detecting the frequency thereof; second means responsive to said speech signal for detecting additional frequencies thereof; third means coupled to said first and second means and responsive to the outputs thereof for producing inhibiting signals proportional to the detected additional frequencies; and fourth means coupled to said first means and said third means and responsive to the outputs thereof, to inhibit said indications of double pitch.
Claim 11
Dependent Claim
91 words
Apparatus for eliminating indications of double pitch which may be produced in a speech analysis system comprising; first means responsive to a speech signal for detecting the frequency thereof; second means responsive to said speech signal for detecting additional frequencies thereof; third means coupled to said first and second means and responsive to the outputs thereof for producing inhibiting signals proportional to the detected additional frequencies; and fourth means coupled to said first means and said third means and responsive to the outputs thereof, to inhibit said indications of double pitch.
Claim 12
Dependent Claim
39 words
The apparatus of claim 9 wherein said second means comprises a plurality of filter means to detect the lowest frequencies of said speech signal, each of said filter means detecting correspondingly higher frequencies and producing an output indicative thereof.
Claim 13
Dependent Claim
39 words
The apparatus of claim 10 wherein said third means comprises means coupled to said plurality of filter means for generating a plurality of pulses of discrete pulse widths, said pulse widths being inversely proportional to said respective detected frequencies.
Claim 14
Dependent Claim
36 words
The apparatus of claim 11 wherein said means for generating a plurality of pulses comprises a plurality of monostable multivibrators, each coupled to one of said plurality of filter means and responsive to the output thereof.
Claim 15
Dependent Claim
51 words
The apparatus of claim 12 wherein said third means comprises inhibit gate means having a plurality of inputs, one of said inputs being coupled to said plurality of monostable multivibrators and responsive to the pulse of greatest width generated thereby, and another of said inputs being coupled to said first means.
Claim 16
Dependent Claim
14 words
The apparatus of claim 13 wherein said first means comprises autocorrelation pitch detection means.
Claim 17
Dependent Claim
15 words
The apparatus of claim 13 wherein said first means comprises envelope emphasis pitch detection means.
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) | 1974-11-01 | 1975-05-03 | 1975-11-02 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1978-11-01 | 1979-05-03 | 1979-11-02 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1982-11-01 | 1983-05-03 | 1983-11-02 | $7700.00 | Window Closed / Lapsed |