US3755627A
Expired / Lapsed
US
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Programmable feature extractor and speech recognizer
Assignee: United States Department of the Navy
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Filing: 1971-12-22
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Granted: 1973-08-28
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Expires: 1991-12-22
Abstract
Abstract A spoken word is analyzed to determine its power spectrum density and slope-intensity product. The recognizer then identifies the word by its unique density and slope-intensity characteristic. The analysis is accomplished through bandpass filters and differentiators which generate signals corresponding to the power spectrum density and slope-intensity product and by a bank of threshold gates which generates binary signals when the power density and the slope-intensity signals are above preset threshold levels. The threshold signals produced are processed through a logic system which indicates which word has been spoken when a unique combination of threshold signals corresponding to a particular word have been triggered.
Inventors
- 👤 S Berkowitz
- 👤 J Carlberg
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-23 15:03
CPC Classifications
G; G10; G10L; G10L15/00
Claims Analysis
Total Claims: 16
Claim 1
Independent Claim
88 words
A programmable feature extractor and speech recognizer, comprising: a first means for generating a first electrical signal in response to a spoken word; a second means connected to said first means for generating an integrated signal indicative of the power spectrum density of said first signal and for generating time differentiated signal indicative of the slope-amplitude product characteristic of said first signal; third means connected to said second means and responsive to said integrated signal and said differentiated signal for indicating the word spoken into said first means.
Claim 2
Dependent Claim
88 words
A programmable feature extractor and speech recognizer, comprising: a first means for generating a first electrical signal in response to a spoken word; a second means connected to said first means for generating an integrated signal indicative of the power spectrum density of said first signal and for generating time differentiated signal indicative of the slope-amplitude product characteristic of said first signal; third means connected to said second means and responsive to said integrated signal and said differentiated signal for indicating the word spoken into said first means.
Claim 3
Dependent Claim
59 words
The system of claim 1 wherein said second means includes: a plurality of bandpass filters for dividing said first signal into predetermined frequency ranges; and said second means includes means connected to the respective outputs of each of said pluralities of bandpass filters for generating said integrated and differentiated signals, in response to said respective bandpass filter output signals.
Claim 4
Dependent Claim
117 words
A system of claim 2 wherein; said second means includes: a silence detector connected to said first means for generating a digital ''''1'''' when said signal from said first means exceeds a predetermined level and for generating a digital ''''0'''' when said signal from said first means is below said predetermined level; said second means including a first and second plurality of threshold detectors; each of said first plurality of threshold detectors connected to a respective integrated signal output and each of said second plurality of threshold detectors connected to a respective differentiated signal output; said threshold detectors being set at predetermined levels for generating signals when said integrated and differentiated output amplitudes exceed said predetermined levels.
Claim 5
Dependent Claim
68 words
The system of claim 3 wherein said third means include a plurality of logic systems, each of said logic systems being connected to said threshold detectors, and to the output of said silence detector according to a predetermined relationship; said logic systems being responsive to said signals generated by said threshold detectors, and said silence detector for generating a signal indicating the word spoken into said first means.
Claim 6
Dependent Claim
110 words
The system of claim 4 wherein the output signals from the logic systems are connected to a dipslay system for indicating the word spoken into said first means; said system including an end of word detector having an input connected to the digital output of said silence detector for indicating a silence corresponding to the end of a word; said system including a Control system responsive to the signal output of said end of word detector and the signals generated by said third means for monitoring the operation of the system and generating the appropriate signals to clear and control the operation of said third means and said display means.
Claim 7
Dependent Claim
57 words
The system of claim 4 wherein: said second means includes a timing logic system connected to a predetermined threshold device for generating a timing signal in response to a predetermined time interval between the appearance of predetermined threshold signals; said third means being responsive to said timing signal for identifying a word spoken into said first means.
Claim 8
Dependent Claim
46 words
A system of claim 2 wherein: said second means includes means connected to the integrated signal output of each bandpass filter for generating a first signal indicative of frequency range of each formant and a second signal indicative of the rate of formant shift in frequency.
Claim 9
Dependent Claim
46 words
The system of claim 7 wherein: said means for generating said first and second signals includes a formant detector having a plurality of inputs, each input connected to a respective said integrand output; said formant detector having a plurality of outputs connected to said third means.
Claim 10
Dependent Claim
101 words
The system of claim 8 wherein: said means for generating said second signal includes a plurality of differentiators; each said differentiator input connected to a respective output of said formant detector; a third plurality of threshold detectors; each of said third plurality threshold detectors being connected to the output of a respective differentiator; a fourth plurality of threshold detectors; each of said fourth plurality of threshold detectors being connected directly to a respective output of said formant detector; said threshold detectors being set at predetermined levels for generating signals when said formant differentiator and formant detector signals exceed said predetermined levels.
Claim 11
Dependent Claim
111 words
The system of claim 9 wherein: said second means includes a silence detector connected to said first means for generating a digital ''''1'''' when said signal from said first means exceeds a predetermined level and for generating a digital ''''0'''' when said first means is below said predetermined level; said third means includes a pluraity of logic trains; each of said logic systems being connected to said threshold detectors, and to the output of said silence detector according to a predetermined relationship; said logic systems being responsive to said signals generated by said threshold detectors, and said silence detector for generating a signal indicating the word spoken into said first means.
Claim 12
Dependent Claim
110 words
The system of claim 10 wherein: the output signals from the logic systems are connected to a display system for indicating the word spoken into said first means; said system including an end of word detector having an input connected to the digital output of said silence detector for indicating a silence corresponding to the end of a word; said system including a control system responsive to the signal output of said end of word detector and the signals generated by said third means for monitoring the operation of the system and generating the appropriate signals to clear and control the operation of said third means and said display means.
Claim 13
Dependent Claim
56 words
The system of claim 10 wherein: said second means includes a timing logic system connected to predetermined threshold device for generating a timing signal in response to a predetermined time interval between the appearance of predetermined threshold signals; said third means being responsive to said timing signal for identifying a word spoken into said first means.
Claim 14
Independent Claim
90 words
A method for identifying and recognizing spoken words comprising the steps: transducing spoken words into continuous electrical signals; filtering signals into discrete bandpass ranges; inputting said filtered sIgnals directly into a first plurality of threshold devices; inputting said filtered signal into a plurality of time differentiators; inputting the output of the time differentiators into a second plurality of threshold devices; adjusting the trigger levels of said first and second plurality of threshold devices to generate unique sets of digital signals, each of said sets corresponding to a respective spoken word.
Claim 15
Independent Claim
90 words
A method for identifying and recognizing spoken words comprising the steps: transducing spoken words into continuous electrical signals; filtering signals into discrete bandpass ranges; inputting said filtered sIgnals directly into a first plurality of threshold devices; inputting said filtered signal into a plurality of time differentiators; inputting the output of the time differentiators into a second plurality of threshold devices; adjusting the trigger levels of said first and second plurality of threshold devices to generate unique sets of digital signals, each of said sets corresponding to a respective spoken word.
Claim 16
Dependent Claim
104 words
The method of claim 13, including the steps of: directly inputting the filtered signal to a formant detector; inputting the formant detector output signal to a third plurality of threshold devices; inputting the formant output signal to a plurality of differentiators; inputting the differentiator output signals to a fourth plurality of threshold devices; adjusting the trigger levels of the threshold devices to generate sets of digital signals; selecting the sets of signals from the first, second, third, and fourth plurality of threshold devices to form unique sets of digital signals representing spoken words; processing said unique sets of signals to identify the spoken words.
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) | 1976-08-27 | 1977-02-26 | 1977-08-28 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1980-08-27 | 1981-02-26 | 1981-08-28 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1984-08-27 | 1985-02-26 | 1985-08-28 | $7700.00 | Window Closed / Lapsed |