US5797123A
Expired / Lapsed
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Method of key-phase detection and verification for flexible speech understanding
Assignee: Nokia of America Corp
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Filing: 1996-12-20
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Granted: 1998-08-18
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Expires: 2016-12-20
Abstract
Abstract A key-phrase detection and verification method that can be advantageously used to realize understanding of flexible (i.e., unconstrained) speech. A "multiple pass" procedure is applied to a spoken utterance comprising a sequence of words (i.e., a "sentence"). First, a plurality of key-phrases are detected (i.e., recognized) based on a set of phrase sub-grammars which may, for example, be specific to the state of the dialogue. These key-phrases are then verified by assigning confidence measures thereto and comparing these confidence measures to a threshold, resulting in a set of verified key-phrase candidates. Next, the verified key-phrase candidates are connected into sentence hypotheses based upon the confidence measures and predetermined (e.g., task-specific) semantic information. And, finally, one or more of these sentence hypotheses are verified to produce a verified sentence hypothesis and, from that, a resultant understanding of the spoken utterance.
Inventors
- 👤 Wu Chou
- 👤 Biing-Hwang Juang
- 👤 Tatsuya Kawahara
- 👤 Chin-hui Lee
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-06 14:09
CPC Classifications
G; G10; G10L; G10L15/00; G10L15/08; G10L15/18; G10L15/1815; G10L2015/088
Claims Analysis
Total Claims: 34
Claim 1
Independent Claim
120 words
A method for performing speech recognition of a spoken utterance comprising a plurality of words, the method comprising the steps of: performing key-phrase detection based on one or more phrase sub-grammars to generate a plurality of detected key-phrases, each detected key-phrase comprising a sequence of one or more recognized words; performing verification on one or more of said detected key-phrases by assigning confidence measures thereto and comparing said confidence measures to one or more threshold values, thereby generating a set of verified key-phrase candidates; connecting the verified key-phrase candidates to generate one or more sentence hypotheses based upon predetermined semantic information; and performing verification on one or more of said sentence hypotheses, thereby generating at least one verified sentence hypothesis.
Claim 2
Independent Claim
120 words
A method for performing speech recognition of a spoken utterance comprising a plurality of words, the method comprising the steps of: performing key-phrase detection based on one or more phrase sub-grammars to generate a plurality of detected key-phrases, each detected key-phrase comprising a sequence of one or more recognized words; performing verification on one or more of said detected key-phrases by assigning confidence measures thereto and comparing said confidence measures to one or more threshold values, thereby generating a set of verified key-phrase candidates; connecting the verified key-phrase candidates to generate one or more sentence hypotheses based upon predetermined semantic information; and performing verification on one or more of said sentence hypotheses, thereby generating at least one verified sentence hypothesis.
Claim 3
Dependent Claim
25 words
The method of claim 1 wherein said one or more phrase sub-grammars are selected from a set of phrase sub-grammars based upon a dialogue state.
Claim 4
Dependent Claim
26 words
The method of claim 1 wherein said one or more phrase sub-grammars have been derived based on a training process using a corpus of speech samples.
Claim 5
Dependent Claim
19 words
The method of claim 1 wherein the generation of said sentence hypotheses is further based on said confidence measures.
Claim 6
Dependent Claim
14 words
The method of claim 1 wherein the detected key-phrases are labeled with semantic tags.
Claim 7
Dependent Claim
23 words
The method of claim 5 wherein the generation of said sentence hypotheses is further based on one or more of said semantic tags.
Claim 8
Dependent Claim
19 words
The method of claim 6 wherein the generation of said sentence hypotheses is further based on said confidence measures.
Claim 9
Dependent Claim
34 words
The method of claim 7 wherein the generation of said sentence hypotheses comprises determining one or more most likely sentence hypotheses based upon said confidence measures, said semantic tags, and said predetermined semantic information.
Claim 10
Dependent Claim
36 words
The method of claim 1 wherein the step of performing key-phrase detection is based on a plurality of subword models, and wherein each of said detected key-phrases further comprises a sequence of one or more subwords.
Claim 11
Dependent Claim
13 words
The method of claim 9 wherein the subword models comprise Hidden Markov Models.
Claim 12
Dependent Claim
35 words
The method of claim 9 wherein the step of performing verification on said detected key-phrases is based on a set of one or more of said subword models and a corresponding set of anti-subword models.
Claim 13
Dependent Claim
17 words
The method of claim 11 wherein the subword models and the anti-subword models comprise Hidden Markov Models.
Claim 14
Dependent Claim
21 words
The method of claim 1 wherein the step of performing verification on said sentence hypotheses comprises performing an acoustic verification thereupon.
Claim 15
Dependent Claim
21 words
The method of claim 1 wherein the step of performing verification on said sentence hypotheses comprises performing a semantic verification thereupon.
Claim 16
Dependent Claim
26 words
The method of claim 1 wherein the generating of the at least one verified sentence hypothesis comprises selecting a most likely one of said sentence hypotheses.
Claim 17
Dependent Claim
23 words
The method of claim 1 further comprising the step of generating a semantic frame based upon the at least one verified sentence hypothesis.
Claim 18
Independent Claim
136 words
An apparatus for performing speech recognition of a spoken utterance comprising a plurality of words, the apparatus comprising: a key-phrase detector adapted to generate a plurality of detected key-phrases based on one or more phrase sub-grammars, each detected key-phrase comprising a sequence of one or more recognized words; a key-phrase verifier applied to one or more of said detected key-phrases, said key-phrase verifier assigning confidence measures to each of said detected key-phrases and comparing said confidence measures to one or more threshold values, thereby generating a set of verified key-phrase candidates; a sentence hypothesizer adapted to connect the verified key-phrase candidates to generate one or more sentence hypotheses based upon the predetermined semantic information; and a sentence hypothesis verifier applied to one or more of said sentence hypotheses, thereby generating at least one verified sentence hypothesis.
Claim 19
Independent Claim
136 words
An apparatus for performing speech recognition of a spoken utterance comprising a plurality of words, the apparatus comprising: a key-phrase detector adapted to generate a plurality of detected key-phrases based on one or more phrase sub-grammars, each detected key-phrase comprising a sequence of one or more recognized words; a key-phrase verifier applied to one or more of said detected key-phrases, said key-phrase verifier assigning confidence measures to each of said detected key-phrases and comparing said confidence measures to one or more threshold values, thereby generating a set of verified key-phrase candidates; a sentence hypothesizer adapted to connect the verified key-phrase candidates to generate one or more sentence hypotheses based upon the predetermined semantic information; and a sentence hypothesis verifier applied to one or more of said sentence hypotheses, thereby generating at least one verified sentence hypothesis.
Claim 20
Dependent Claim
25 words
The apparatus of claim 17 wherein said one or more phrase sub-grammars are selected from a set of phrase sub-grammars based upon a dialogue state.
Claim 21
Dependent Claim
26 words
The apparatus of claim 17 wherein said one or more phrase sub-grammars have been derived based on a training process using a corpus of speech samples.
Claim 22
Dependent Claim
19 words
The apparatus of claim 17 wherein the sentence hypothesizer generates said sentence hypotheses further based on said confidence measures.
Claim 23
Dependent Claim
14 words
The apparatus of claim 17 wherein the detected key-phrases are labeled with semantic tags.
Claim 24
Dependent Claim
23 words
The apparatus of claim 21 wherein the sentence hypothesizer generates said sentence hypotheses further based on one or more of said semantic tags.
Claim 25
Dependent Claim
19 words
The apparatus of claim 22 wherein the sentence hypothesizer generates said sentence hypotheses further based on said confidence measures.
Claim 26
Dependent Claim
30 words
The apparatus of claim 23 wherein the sentence hypothesizer determines one or more most likely sentence hypotheses based upon said confidence measures, said semantic tags, and said predetermined semantic information.
Claim 27
Dependent Claim
33 words
The apparatus of claim 17 wherein the key-phrase detector operates based on a plurality of subword models, and wherein each of said detected key-phrases further comprises a sequence of one or more subwords.
Claim 28
Dependent Claim
13 words
The apparatus of claim 25 wherein the subword models comprise Hidden Markov Models.
Claim 29
Dependent Claim
29 words
The apparatus of claim 25 wherein the key-phrase verifier operates based on a set of one or more of said subword models and a corresponding set of anti-subword models.
Claim 30
Dependent Claim
17 words
The apparatus of claim 27 wherein the subword models and the anti-subword models comprise Hidden Markov Models.
Claim 31
Dependent Claim
18 words
The apparatus of claim 17 wherein the sentence hypothesis verifier performs an acoustic verification on said sentence hypotheses.
Claim 32
Dependent Claim
18 words
The apparatus of claim 17 wherein the sentence hypothesis verifier performs a semantic verification on said sentence hypotheses.
Claim 33
Dependent Claim
19 words
The apparatus of claim 17 wherein the sentence hypothesis verifier selects a most likely one of said sentence hypotheses.
Claim 34
Dependent Claim
26 words
The apparatus of claim 17 further comprising a semantic frame generator operable to generate a semantic frame based upon the at least one verified sentence hypothesis.
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) | 2001-08-17 | 2002-02-16 | 2002-08-18 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2005-08-17 | 2006-02-16 | 2006-08-18 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2009-08-17 | 2010-02-16 | 2010-08-18 | $7700.00 | Window Closed / Lapsed |