US5202926A
Expired / Lapsed
US
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Phoneme discrimination method
Assignee: Oki Electric Industry Co Ltd
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Filing: 1991-09-12
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Granted: 1993-04-13
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Expires: 2011-09-12
Abstract
Abstract To improve the accuracy of phoneme discrimination, a first phoneme discrimination method composes analyzing, not only static information on a voice but also dynamic information on the voice, power variations of the voice as a power-change pattern (PCP) and spectrum parameter variations of the voice as a time spectrum parameter pattern (TSP). After rough clustering based on the PCP, detailed classification is conducted using the TSP so that the voice is hierarchically discriminated to obtain phoneme symbols. This invention also provides a second phoneme discrimination method. To improve the accuracy of phoneme discrimination by a recognition system for unspecified, independent speakers, plural spectrum parameter codebooks classified in advance depending on voice qualities are provided. After rough clustering based on the PCP, the inputted voice is subjected to detailed discrimination with reference to plural codebooks corresponding to the PCP and also to voice quality determination, thereby obtaining phoneme symbols.
Inventors
- 👤 Kei Miki
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-30 21:32
CPC Classifications
G; G10; G10L; G10L15/00; G10L15/02; G10L2015/025
Claims Analysis
Total Claims: 24
Claim 1
Independent Claim
135 words
A phoneme discrimination method comprising the steps of: analyzing the frequency of an inputted voice signal to compute, for predetermined time frame intervals, voice spectrum parameters and voice powers indicative of the intensity of the inputted voice; combining the voice powers of adjacent frames to provide a power-change pattern (PCP) indicative of the time variance of the voice powers; combining the spectrum parameters of neighboring frames to provide a time spectrum pattern (TSP) indicative of the time variance of the spectrum parameters; vector-quantizing the PCP to determine power-change pattern codes (PCP codes); vector-quantizing the TSP using a TSP codebook corresponding to the PCP-VQ codes in the respective frames to obtain TSP codes; and determining the probable phoneme symbol of each time frame interval via a correlation of phoneme symbols to PCP code and TSP code.
Claim 2
Dependent Claim
135 words
A phoneme discrimination method comprising the steps of: analyzing the frequency of an inputted voice signal to compute, for predetermined time frame intervals, voice spectrum parameters and voice powers indicative of the intensity of the inputted voice; combining the voice powers of adjacent frames to provide a power-change pattern (PCP) indicative of the time variance of the voice powers; combining the spectrum parameters of neighboring frames to provide a time spectrum pattern (TSP) indicative of the time variance of the spectrum parameters; vector-quantizing the PCP to determine power-change pattern codes (PCP codes); vector-quantizing the TSP using a TSP codebook corresponding to the PCP-VQ codes in the respective frames to obtain TSP codes; and determining the probable phoneme symbol of each time frame interval via a correlation of phoneme symbols to PCP code and TSP code.
Claim 3
Dependent Claim
150 words
A phoneme discrimination method comprising the steps of: analyzing the frequency of an inputted voice signal to obtain, for predetermined time frame intervals voice spectrum parameters and voice powers indicative of the intensity of the inputted voice; combining the voice powers of adjacent frames to provide a power-change pattern (PCP) indicative of the time variance of the voice powers; vector-quantizing the PCP to obtain power-change pattern VQ codes (PCP-VQ codes); vector-quantizing the spectrum parameters using plural spectrum parameter codebooks to obtain plural spectrum parameter VQ codes and plural quantization errors (VQ errors); selecting the spectrum parameter codebook to minimize the sum of the plural VQ errors, and selecting optimal spectrum parameter codes on the basis of the spectrum parameter codebook so selected; and determining the probable phoneme symbol of each frame via a correlation of phoneme symbols to a selected codebook, an optimal spectrum parameter code and a PCP code.
Claim 4
Dependent Claim
150 words
A phoneme discrimination method comprising the steps of: analyzing the frequency of an inputted voice signal to obtain, for predetermined time frame intervals voice spectrum parameters and voice powers indicative of the intensity of the inputted voice; combining the voice powers of adjacent frames to provide a power-change pattern (PCP) indicative of the time variance of the voice powers; vector-quantizing the PCP to obtain power-change pattern VQ codes (PCP-VQ codes); vector-quantizing the spectrum parameters using plural spectrum parameter codebooks to obtain plural spectrum parameter VQ codes and plural quantization errors (VQ errors); selecting the spectrum parameter codebook to minimize the sum of the plural VQ errors, and selecting optimal spectrum parameter codes on the basis of the spectrum parameter codebook so selected; and determining the probable phoneme symbol of each frame via a correlation of phoneme symbols to a selected codebook, an optimal spectrum parameter code and a PCP code.
Claim 5
Dependent Claim
25 words
The method of claim 1 wherein said determining step includes using a table of data correlating phonemes to PCP code data and TSP code data.
Claim 6
Dependent Claim
18 words
The method of claim 1 wherein said steps of vector-quantizing include referencing one or more previously prepared codebooks.
Claim 7
Dependent Claim
23 words
The method of claim 1 wherein said step of vector-quantizing the PCP includes operating a PCP-VQ unit which references a previously-prepared PCP codebook.
Claim 8
Dependent Claim
23 words
The method of claim 5 wherein said step of vector-quantizing the TSP includes operating a TSP-VQ unit which references a previously-prepared TSP codebook.
Claim 9
Dependent Claim
23 words
The method of claim 1 wherein said step of vector-quantizing the TSP includes operating a TSP-VQ unit which references a previously-prepared TSP codebook.
Claim 10
Dependent Claim
79 words
The method of claim 1 wherein said PCP vector-quantization step is in accordance with the formula: ##EQU5## where the index m is an integer ranging from 1 to M, where d(P i , Y m ) indicates the distance between the PCP P i and the PCP Y m of the power code number m, where argmin means to determine the power code number which makes said distance shortest, and where M is the size of a PCP codebook.
Claim 11
Dependent Claim
36 words
The method of claim 1 wherein said step of vector-quantizing the TSP includes selecting the TSP codebook corresponding to the PCP code from a set of TSP codebooks and vector quantizing using the codebook so selected.
Claim 12
Dependent Claim
84 words
The method of claim 9 wherein said step of vector-quantizing the TSP is in accordance with the following formula: ##EQU6## where the PCP code is C i , the time spectrum pattern code is Z i , where U(C i ) r corresponds to the code C i and is a TSP comprising (2k+1)*J elements, where r is a code number allotted to each TSP, and where R(C i ) means the size of the TSP codebook corresponding to the code C i .
Claim 13
Dependent Claim
28 words
The method of claim 2 wherein said determining step includes using a table of data correlating phonemes to the codebook, spectrum parameter code data, and PCP code data.
Claim 14
Dependent Claim
110 words
A phoneme discrimination unit comprising: an acoustic analyzer configured to provide voice spectrum parameters and voice powers indicative of the intensity of inputted voice signals; a power-change patter (PCP) generator coupled to receive said voice powers from the acoustic analyzer; a PCP vector quantizing unit coupled to the PCP generator; a time spectrum parameter (TSP) pattern generator coupled to receive said voice spectrum parameters from the acoustic analyzer; a TSP vector quantizing unit coupled to receive inputs from said TSP pattern generator and said PCP vector quantizing unit; a phoneme determining unit coupled to receive inputs from said TSP vector quantizing unit; and an output from said phoneme determining unit.
Claim 15
Dependent Claim
110 words
A phoneme discrimination unit comprising: an acoustic analyzer configured to provide voice spectrum parameters and voice powers indicative of the intensity of inputted voice signals; a power-change patter (PCP) generator coupled to receive said voice powers from the acoustic analyzer; a PCP vector quantizing unit coupled to the PCP generator; a time spectrum parameter (TSP) pattern generator coupled to receive said voice spectrum parameters from the acoustic analyzer; a TSP vector quantizing unit coupled to receive inputs from said TSP pattern generator and said PCP vector quantizing unit; a phoneme determining unit coupled to receive inputs from said TSP vector quantizing unit; and an output from said phoneme determining unit.
Claim 16
Dependent Claim
19 words
The phoneme discriminating unit of claim 12 further comprising a PCP codebook coupled to said PCP vector quantizing unit.
Claim 17
Dependent Claim
21 words
The phoneme discriminating unit of claim 13 further comprising a set of TSP codebooks coupled to said TSP vector quantizing unit.
Claim 18
Dependent Claim
21 words
The phoneme discriminating unit of claim 12 further comprising a set of TSP codebooks coupled to said TSP vector quantizing unit.
Claim 19
Independent Claim
93 words
A method of discriminating phonemes from an inputted voice signal comprising the steps of: extracting voice powers and spectrum parameters from said inputted voice signal by an acoustic analysis process; obtaining a power change pattern (PCP) code from said voice powers; processing the spectrum parameters to produce a time spectrum pattern (TSP); vector-quantizing the TSP to obtain a TSP code after selecting from among a plurality of TSP codebooks one TSP codebook corresponding to the PCP code; and thereafter selecting a phoneme as a function of the PCP code and the TSP code.
Claim 20
Independent Claim
93 words
A method of discriminating phonemes from an inputted voice signal comprising the steps of: extracting voice powers and spectrum parameters from said inputted voice signal by an acoustic analysis process; obtaining a power change pattern (PCP) code from said voice powers; processing the spectrum parameters to produce a time spectrum pattern (TSP); vector-quantizing the TSP to obtain a TSP code after selecting from among a plurality of TSP codebooks one TSP codebook corresponding to the PCP code; and thereafter selecting a phoneme as a function of the PCP code and the TSP code.
Claim 21
Dependent Claim
16 words
The method of claim 16 wherein said selecting step includes referring to a previously stored table.
Claim 22
Dependent Claim
37 words
The method of claim 16 wherein said step of obtaining a PCP code includes combining a plurality of said voice powers to provide a PCP and vector-quantizing the PCP, including referring to a previously stored PCP codebook.
Claim 23
Dependent Claim
13 words
The method of claim 16 wherein said TSP codebooks have been previously stored.
Claim 24
Dependent Claim
34 words
The method of claim 16 wherein said acoustic analysis process provides said voice powers and said spectrum parameters for respective time intervals, and the step of selecting a phoneme corresponds to said time intervals.
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) | 1996-04-12 | 1996-10-12 | 1997-04-13 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2000-04-12 | 2000-10-12 | 2001-04-13 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2004-04-12 | 2004-10-12 | 2005-04-13 | $7700.00 | Window Closed / Lapsed |