Patent US5774836A successfully refreshed from Google Patents.
US5774836A
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US
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System and method for performing pitch estimation and error checking on low estimated pitch values in a correlation based pitch estimator
Assignee: Samsung Electronics Co Ltd
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Filing: 1996-04-01
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Granted: 1998-06-30
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Expires: 2016-04-01
Abstract
Abstract An improved vocoder system and method for estimating pitch in a speech waveform which more accurately disregards false pitch estimates resulting from secondary excitations. The vocoder system first performs a correlation calculation on a speech frame and generates an estimated pitch value. The present invention then compares the estimated or determined pitch with a threshold value to determine if the determined or estimated pitch has a suspiciously low pitch value. If so, the present invention performs error checking to disregard pitch estimates that are the result of the First Formant frequency's contribution to the pitch estimation process. The error checking involves examining the higher multiples of the determined pitch value to ascertain whether the determined pitch value might be incorrect. The present invention determines whether one or more higher multiples are missing, whether the higher multiples are related by a common factor, and whether adjacent multiples have missing peaks. The error checking also involves searching for missing or low correlation peaks in the neighborhood of missing higher multiples of the determined pitch. If the error checking indicates that the determined pitch is probably incorrect, then a new determination is made without the correlation peak corresponding to the rejected determined pitch. This provides a more accurate pitch estimation, thus enhancing voice storage quality. The present invention thus comprises an improved correlation method for estimating the pitch parameter which more accurately disregards false correlation peaks resulting from secondary excitations, including the contribution of the First Formant.
Inventors
- 👤 John G. Bartkowiak
- 👤 Mark Ireton
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-09 13:13
CPC Classifications
G; G10; G10L; G10L25/00; G10L25/90; G10L25/03; G10L25/06
Claims Analysis
Total Claims: 23
Claim 1
Independent Claim
246 words
A method for performing pitch error checking in a correlation-based pitch estimator, comprising: receiving a speech waveform comprising a plurality of frames; performing a correlation calculation for a first frame of said plurality of frames of said speech waveform, wherein said correlation calculation produces one or more correlation peaks; determining a first determined pitch value for said first frame from said one or more correlation peaks, wherein said first determined pitch value corresponds to a first determined correlation peak; determining if said first determined pitch value is less than a pitch threshold value; setting said first determined pitch value as a pitch value for said first frame if said first determined pitch value is not less than said pitch threshold value; performing error checking on said first determined pitch value to determine if said first determined pitch value should be set as the pitch value for said first frame if said first determined pitch value is less than said pitch threshold value, wherein said performing error checking includes determining if any pitch multiples of said first determined pitch value have missing correlation peaks; and determining a new determined pitch value for said first frame from at least a subset of said one or more correlation peaks, wherein said determining said new determined pitch value does not use said first determined correlation peak, wherein said determining said new determined pitch value is performed if any pitch multiples of said first determined pitch value have missing correlation peaks.
Claim 2
Independent Claim
246 words
A method for performing pitch error checking in a correlation-based pitch estimator, comprising: receiving a speech waveform comprising a plurality of frames; performing a correlation calculation for a first frame of said plurality of frames of said speech waveform, wherein said correlation calculation produces one or more correlation peaks; determining a first determined pitch value for said first frame from said one or more correlation peaks, wherein said first determined pitch value corresponds to a first determined correlation peak; determining if said first determined pitch value is less than a pitch threshold value; setting said first determined pitch value as a pitch value for said first frame if said first determined pitch value is not less than said pitch threshold value; performing error checking on said first determined pitch value to determine if said first determined pitch value should be set as the pitch value for said first frame if said first determined pitch value is less than said pitch threshold value, wherein said performing error checking includes determining if any pitch multiples of said first determined pitch value have missing correlation peaks; and determining a new determined pitch value for said first frame from at least a subset of said one or more correlation peaks, wherein said determining said new determined pitch value does not use said first determined correlation peak, wherein said determining said new determined pitch value is performed if any pitch multiples of said first determined pitch value have missing correlation peaks.
Claim 3
Dependent Claim
101 words
The method of claim 1, wherein said performing said error checking further comprises: determining if said correlation peaks other than said first determined correlation peak have a common factor; wherein said determining if any pitch multiples of said first determined pitch value have missing correlation peaks is performed if said peaks other than said first determined correlation peak have a common factor; wherein said determining said new determined pitch value is performed if said peaks other than said first determined correlation peak have a common factor and if any pitch multiples of said first determined pitch value have missing correlation peaks.
Claim 4
Dependent Claim
82 words
The method of claim 2, wherein said one or more correlation peaks have correlation peak locations, wherein said determining if said correlation peaks other than said first determined correlation peak have a common factor comprises: dividing said correlation peak locations of said one or more correlation peaks determined in said performing correlation calculations by said first determined pitch value to produce a plurality of integer values; and determining if said plurality of integer values are related by one or more common factors.
Claim 5
Dependent Claim
73 words
The method of claim 3, further comprising: determining if said plurality of integer values contains a 1 value; and determining a lowest pitch multiple value of said first determined pitch value if said plurality of integer values does not contain a 1 value; wherein said determining if said plurality of integer values are related by one or more common factors is performed only if said plurality of integer values contains a 1 value.
Claim 6
Dependent Claim
102 words
The method of claim 4, further comprising: determining if there are missing integers between 1 and the highest integer in said plurality of integer values after determining said plurality of integer values; and setting said first determined pitch value as said pitch value for said first frame if there are no missing integers between 1 and the highest integer in said plurality of integer values; wherein said determining if said plurality of integer values are related by one or more common factors is performed only if there are missing integers between 1 and the highest integer in said plurality of integer values.
Claim 7
Dependent Claim
93 words
The method of claim 1, wherein said performing said error checking further comprises: searching for a correlation peak at one or more pitch multiples of said first determined pitch value which have missing correlation peaks in response to determining that one or more pitch multiples of said first determined pitch value have missing correlation peaks; setting said first determined pitch value as said pitch value for said first frame if a correlation peak exists at one or more of said pitch multiples of said first determined pitch value which have missing correlation peaks.
Claim 8
Dependent Claim
80 words
The method of claim 6, wherein said searching for a correlation peak at one or more pitch multiples of said first determined pitch value which have missing correlation peaks comprises: determining if a correlation peak exists at one or more of said pitch multiples of said first determined pitch value which have missing correlation peaks; and comparing said correlation peak at a pitch multiple of said first determined pitch value which has a missing correlation peak with a threshold value.
Claim 9
Dependent Claim
62 words
The method of claim 6, wherein said determining if a correlation peak exists at one or more of said pitch multiples of said first determined pitch value which have missing correlation peaks comprises determining if a correlation peak exists within a window of said one or more of said pitch multiples of said first determined pitch value which have missing correlation peaks.
Claim 10
Dependent Claim
38 words
The method of claim 6, further comprising: rejecting said first determined pitch value if a correlation peak does not exist at said one or more pitch multiples of said first determined pitch value which have missing correlation peaks.
Claim 11
Dependent Claim
39 words
The method of claim 1, further comprising: setting said first determined pitch value as said pitch value for said first frame if said if none of said pitch multiples of said first determined pitch value have missing correlation peaks.
Claim 12
Dependent Claim
141 words
The method of claim 10, wherein said steps of determining a first determined pitch value for said first frame from said one or more correlation peaks, determining if said first determined pitch value is less than a pitch threshold value, setting said first determined pitch value as said pitch value for said first frame if said first determined pitch value is not less than said pitch threshold value, performing error checking on said determined pitch value, determining a new determined pitch value for said frame, and setting said first determined pitch value as said pitch value for said first frame if said if none of said pitch multiples of said first determined pitch value have missing correlation peaks are performed a plurality of times until one of said determined pitch values is set as said pitch value for said first frame.
Claim 13
Independent Claim
286 words
A method for performing pitch error checking in a correlation-based pitch estimator, comprising: receiving a speech waveform comprising a plurality of frames; performing a correlation calculation for a first frame of said plurality of frames of said speech waveform, wherein said correlation calculation produces one or more correlation peaks; determining a first determined pitch value for said first frame from said one or more correlation peaks, wherein said first determined pitch value corresponds to a determined correlation peak; determining if said first determined pitch value is less than a pitch threshold value; setting said first determined pitch value as a pitch value for said first frame if said first determined pitch value is not less than said pitch threshold value; performing error checking on said first determined pitch value to determine if said first determined pitch value should be set to the pitch value of said first frame if said first determined pitch value is less than said pitch threshold value, wherein said performing error checking comprises: determining if said correlation peaks other than said determined correlation peak have a common factor; and determining if any pitch multiples of said first determined pitch value have missing correlation peaks if said peaks other than said determined correlation peak have a common factor; and determining a new determined pitch value for said first frame from a subset of said one or more correlation peaks, wherein said determining said new determined pitch value does not use said determined correlation peak, wherein said determining said new determined pitch value is performed if said correlation peaks other than said determined correlation peak have a common factor and if any pitch multiples of said first determined pitch value have missing correlation peaks.
Claim 14
Independent Claim
286 words
A method for performing pitch error checking in a correlation-based pitch estimator, comprising: receiving a speech waveform comprising a plurality of frames; performing a correlation calculation for a first frame of said plurality of frames of said speech waveform, wherein said correlation calculation produces one or more correlation peaks; determining a first determined pitch value for said first frame from said one or more correlation peaks, wherein said first determined pitch value corresponds to a determined correlation peak; determining if said first determined pitch value is less than a pitch threshold value; setting said first determined pitch value as a pitch value for said first frame if said first determined pitch value is not less than said pitch threshold value; performing error checking on said first determined pitch value to determine if said first determined pitch value should be set to the pitch value of said first frame if said first determined pitch value is less than said pitch threshold value, wherein said performing error checking comprises: determining if said correlation peaks other than said determined correlation peak have a common factor; and determining if any pitch multiples of said first determined pitch value have missing correlation peaks if said peaks other than said determined correlation peak have a common factor; and determining a new determined pitch value for said first frame from a subset of said one or more correlation peaks, wherein said determining said new determined pitch value does not use said determined correlation peak, wherein said determining said new determined pitch value is performed if said correlation peaks other than said determined correlation peak have a common factor and if any pitch multiples of said first determined pitch value have missing correlation peaks.
Claim 15
Independent Claim
230 words
A method for performing pitch error checking in a correlation-based pitch estimator, comprising: receiving a speech waveform comprising a plurality of frames; performing a correlation calculation for a first frame of said plurality of frames of said speech waveform, wherein said correlation calculation produces one or more correlation peaks; determining a first determined pitch value for said first frame from said one or more correlation peaks, wherein said first determined pitch value corresponds to a first determined correlation peak; determining if said first determined pitch value is less than a pitch threshold value; setting said first determined pitch value as a pitch value for said first frame if said first determined pitch value is not less than said pitch threshold value; performing error checking on said first determined pitch value to determine if said first determined pitch value should be set as the pitch value for said first frame if said first determined pitch value is less than said pitch threshold value, wherein said performing error checking includes analyzing pitch multiples of said first determined pitch value; and determining a new determined pitch value for said first frame from at least a subset of said one or more correlation peaks if said analyzing said pitch multiples of said first determined pitch value indicates that said first determined pitch value may not be the correct pitch value of said first frame.
Claim 16
Independent Claim
230 words
A method for performing pitch error checking in a correlation-based pitch estimator, comprising: receiving a speech waveform comprising a plurality of frames; performing a correlation calculation for a first frame of said plurality of frames of said speech waveform, wherein said correlation calculation produces one or more correlation peaks; determining a first determined pitch value for said first frame from said one or more correlation peaks, wherein said first determined pitch value corresponds to a first determined correlation peak; determining if said first determined pitch value is less than a pitch threshold value; setting said first determined pitch value as a pitch value for said first frame if said first determined pitch value is not less than said pitch threshold value; performing error checking on said first determined pitch value to determine if said first determined pitch value should be set as the pitch value for said first frame if said first determined pitch value is less than said pitch threshold value, wherein said performing error checking includes analyzing pitch multiples of said first determined pitch value; and determining a new determined pitch value for said first frame from at least a subset of said one or more correlation peaks if said analyzing said pitch multiples of said first determined pitch value indicates that said first determined pitch value may not be the correct pitch value of said first frame.
Claim 17
Dependent Claim
67 words
The method of claim 13, wherein said analyzing said pitch multiples of said first determined pitch value includes determining if any pitch multiples of said first determined pitch value have missing correlation peaks; wherein one or more pitch multiples of said first determined pitch value having missing correlation peaks indicates that said first determined pitch value may not be the correct pitch value of said first frame.
Claim 18
Dependent Claim
101 words
The method of claim 14, wherein said performing said error checking further comprises: determining if said correlation peaks other than said first determined correlation peak have a common factor; wherein said determining if any pitch multiples of said first determined pitch value have missing correlation peaks is performed if said peaks other than said first determined correlation peak have a common factor; wherein said determining said new determined pitch value is performed if said peaks other than said first determined correlation peak have a common factor and if any pitch multiples of said first determined pitch value have missing correlation peaks.
Claim 19
Dependent Claim
82 words
The method of claim 15, wherein said one or more correlation peaks have correlation peak locations, wherein said determining if said correlation peaks other than said first determined correlation peak have a common factor comprises: dividing said correlation peak locations of said one or more correlation peaks determined in said performing correlation calculations by said first determined pitch value to produce a plurality of integer values; and determining if said plurality of integer values are related by one or more common factors.
Claim 20
Dependent Claim
293 words
A vocoder which performs pitch estimation and error checking, comprising: means for receiving a plurality of digital samples of a speech waveform, wherein the speech waveform includes a plurality of frames each comprising a plurality of samples; a processor for determining a pitch value for each of said frames, wherein said processor comprises: means for performing a correlation calculation for a first frame of said plurality of frames of said speech waveform, wherein said correlation calculation produces one or more correlation peaks; means for determining a first determined pitch value for said first frame from said one or more correlation peaks, wherein said first determined pitch value corresponds to a first determined correlation peak; means for determining if said first determined pitch value is less than a pitch threshold value; means for setting said first determined pitch value as a pitch value for said first frame if said first determined pitch value is not less than said pitch threshold value; means for performing error checking on said first determined pitch value to determine if said first determined pitch value should be set as the pitch value for said first frame if said first determined pitch value is less than said pitch threshold value, wherein said means for performing error checking determines if any pitch multiples of said first determined pitch value have missing correlation peaks; and means for determining a new determined pitch value for said first frame from at least a subset of said one or more correlation peaks, wherein said means for determining a new determined pitch value does not use said first determined correlation peak, wherein said means for determining a new determined pitch value operates if any pitch multiples of said first determined pitch value have missing correlation peaks.
Claim 21
Dependent Claim
293 words
A vocoder which performs pitch estimation and error checking, comprising: means for receiving a plurality of digital samples of a speech waveform, wherein the speech waveform includes a plurality of frames each comprising a plurality of samples; a processor for determining a pitch value for each of said frames, wherein said processor comprises: means for performing a correlation calculation for a first frame of said plurality of frames of said speech waveform, wherein said correlation calculation produces one or more correlation peaks; means for determining a first determined pitch value for said first frame from said one or more correlation peaks, wherein said first determined pitch value corresponds to a first determined correlation peak; means for determining if said first determined pitch value is less than a pitch threshold value; means for setting said first determined pitch value as a pitch value for said first frame if said first determined pitch value is not less than said pitch threshold value; means for performing error checking on said first determined pitch value to determine if said first determined pitch value should be set as the pitch value for said first frame if said first determined pitch value is less than said pitch threshold value, wherein said means for performing error checking determines if any pitch multiples of said first determined pitch value have missing correlation peaks; and means for determining a new determined pitch value for said first frame from at least a subset of said one or more correlation peaks, wherein said means for determining a new determined pitch value does not use said first determined correlation peak, wherein said means for determining a new determined pitch value operates if any pitch multiples of said first determined pitch value have missing correlation peaks.
Claim 22
Dependent Claim
94 words
The vocoder of claim 17, wherein said means for performing error checking further comprises: means for determining if said correlation peaks other than said first determined correlation peak have a common factor; wherein said means for performing error checking operates if said peaks other than said first determined correlation peak have a common factor; wherein said means for determining a new determined pitch value operates if said peaks other than said first determined correlation peak have a common factor and if any pitch multiples of said first determined pitch value have missing correlation peaks.
Claim 23
Dependent Claim
79 words
The vocoder of claim 18, wherein said one or more correlation peaks have correlation peak locations, wherein said means for performing error checking further comprises: means for dividing said correlation peak locations of said one or more correlation peaks determined by said means for performing a correlation calculation by said first determined pitch value to produce a plurality of integer values; and means for determining if said plurality of integer values are related by one or more common factors.
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 2001-06-29 | 2001-12-29 | 2002-06-30 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2005-06-29 | 2005-12-29 | 2006-06-30 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2009-06-29 | 2009-12-29 | 2010-06-30 | $7700.00 | Window Closed / Lapsed |