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US5490234A Expired / Lapsed US ⏱️ 0.0 years remaining

Waveform blending technique for text-to-speech system

Assignee: Apple Inc
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Filing: 1993-01-21
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Granted: 1996-02-06
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Expires: 2013-01-21
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Abstract

Abstract A concatenator for a first digital frame with a second digital frame, such as the ending and beginning of adjacent diphone strings being concatenated to form speech is based on determining an optimum blend point for the first and second digital frames in response to the magnitudes of samples in the first and second digital frames. The frames are then blended to generate a digital sequence representing a concatenation of the first and second frames with reference to the optimum blend point. The system operates by first computing an extended frame in response to the first digital frame, and then finding a subset of the extended frame with matches the second digital frame using a minimum average magnitude difference function over the samples in the subset. The blend point is the first sample of the matching subset. To generate the concatenated waveform, the subset of the extended frame is combined with the second digital frame and concatenated with the beginning segments of the extended frame to produce the concatenate waveform.

Inventors

  • 👤 Shankar Narayan

Bibliographic Details

Application Number —
Jurisdiction US
Data Source google_patents
Last Synchronized 2026-11-09 15:57
CPC Classifications
G; G10; G10L; G10L13/00; G10L13/06; G10L13/07

Claims Analysis

Total Claims: 29
Claim 1
Independent Claim 120 words
An apparatus for concatenating a first digital frame of N samples having respective magnitudes representing a first quasi-periodic waveform and a second digital frame of M samples having respective magnitudes representing a second quasi-periodic waveform, comprising: a buffer store to store the samples of first and second digital frames; means, coupled to the buffer store, for determining a blend point for the first and second digital frames in response to magnitudes of samples in the first and second digital frames; blending means, coupled with the buffer store and the means for determining, for computing a digital sequence representing a concatenation of the first and second quasi-periodic waveforms in response to the first frame, the second frame and the blend point.
Claim 2
Independent Claim 120 words
An apparatus for concatenating a first digital frame of N samples having respective magnitudes representing a first quasi-periodic waveform and a second digital frame of M samples having respective magnitudes representing a second quasi-periodic waveform, comprising: a buffer store to store the samples of first and second digital frames; means, coupled to the buffer store, for determining a blend point for the first and second digital frames in response to magnitudes of samples in the first and second digital frames; blending means, coupled with the buffer store and the means for determining, for computing a digital sequence representing a concatenation of the first and second quasi-periodic waveforms in response to the first frame, the second frame and the blend point.
Claim 3
Dependent Claim 24 words
The apparatus of claim 1, further including: transducer means, coupled to the means for computing, for transducing the digital sequence to an analog waveform.
Claim 4
Dependent Claim 56 words
The apparatus of claim 1, wherein the means for determining includes: first means for computing an extended frame in response to the first digital frame; second means for finding a subset of the extended frame which provides an optimum match to the second digital frame, and defining the blend point as a sample in the subset.
Claim 5
Dependent Claim 25 words
The apparatus of claim 3, wherein the extended frame comprises a concatenation of the first digital frame with a replica of the first digital frame.
Claim 6
Dependent Claim 46 words
The apparatus of claim 3, wherein the subset of the extended frame which matches the second digital frame relatively well comprises a subset with a minimum average magnitude difference over the samples in the subset, and the blend point comprises a first sample in the subset.
Claim 7
Dependent Claim 74 words
The apparatus of claim 1, wherein the means for determining includes: first means for computing an extended frame comprising a discontinuity-smoothed concatenation of the first digital frame with a replica of the first digital frame; second means for finding a subset of the extended frame with a minimum average magnitude difference between the samples in the subset and the second digital frame, and defining the blend point as a first sample in the subset.
Claim 8
Dependent Claim 90 words
The apparatus of claim 1, wherein the blending means includes: means for supplying a first set of samples derived from the first digital frame and the blend point as a first segment of the digital sequence; and means for combining the second digital frame with a second set of samples derived from the first digital frame and the blend point, with emphasis on the second set in a starting sample and emphasis on the second digital frame in an ending sample to produce a second segment of the digital sequence.
Claim 9
Dependent Claim 154 words
The apparatus of claim 1, wherein the means for determining includes: first means for computing an extended frame comprising a discontinuity-smoothed concatenation of the first digital frame with a replica of the first digital frame; second means for finding a subset of the extended frame with a minimum average magnitude difference between the samples in the subset and the second digital frame, and defining the blend point as a first sample in the subset; and wherein the blending means includes: means for supplying a first set of samples derived from the first digital frame and the blend point as a first segment of the digital sequence; and means for combining the second digital frame with the subset of the extended frame, with emphasis on the subset of the extended frame in a starting sample and emphasis on the second digital frame in an ending sample to produce a second segment of the digital sequence.
Claim 10
Dependent Claim 44 words
The apparatus of claim 8, wherein the first and second digital frames represent endings and beginnings respectively of adjacent diphones in speech, and further including: transducer means, coupled to the blending means, for transducing the digital sequence to a sound corresponding to the speech.
Claim 11
Independent Claim 137 words
An apparatus for concatenating a first digital frame of N samples having respective magnitudes representing a first sound segment and a second digital frame of M samples having respective magnitudes representing a second sound segment, comprising: a buffer store to store the samples of first and second digital frames; means, coupled to the buffer store, for determining a blend point for the first and second digital frames in response to magnitudes of samples in the first and second digital frames; blending means, coupled with the buffer store and the means for determining, for computing a digital sequence representing a concatenation of the first and second sound segments in response to the first digital frame, the second digital frame and the blend point; and transducer means, coupled to the blending means, for transducing the digital sequence to sound.
Claim 12
Independent Claim 137 words
An apparatus for concatenating a first digital frame of N samples having respective magnitudes representing a first sound segment and a second digital frame of M samples having respective magnitudes representing a second sound segment, comprising: a buffer store to store the samples of first and second digital frames; means, coupled to the buffer store, for determining a blend point for the first and second digital frames in response to magnitudes of samples in the first and second digital frames; blending means, coupled with the buffer store and the means for determining, for computing a digital sequence representing a concatenation of the first and second sound segments in response to the first digital frame, the second digital frame and the blend point; and transducer means, coupled to the blending means, for transducing the digital sequence to sound.
Claim 13
Dependent Claim 56 words
The apparatus of claim 10, wherein the means for determining includes: first means for computing an extended frame in response to the first digital frame; second means for finding a subset of the extended frame which provides an optimum match to the second digital frame, and defining the blend point as a sample in the subset.
Claim 14
Dependent Claim 25 words
The apparatus of claim 11, wherein the extended frame comprises a concatenation of the first digital frame with a replica of the first digital frame.
Claim 15
Dependent Claim 46 words
The apparatus of claim 11, wherein the subset of the extended frame which matches the second digital frame relatively well comprises a subset with a minimum average magnitude difference over the samples in the subset, and the blend point comprises a first sample in the subset.
Claim 16
Dependent Claim 74 words
The apparatus of claim 10, wherein the means for determining includes: first means for computing an extended frame comprising a discontinuity-smoothed concatenation of the first digital frame with a replica of the first digital frame; second means for finding a subset of the extended frame with a minimum average magnitude difference between the samples in the subset and the second digital frame, and defining the blend point as a first sample in the subset.
Claim 17
Dependent Claim 90 words
The apparatus of claim 10, wherein the blending means includes: means for supplying a first set of samples derived from the first digital frame and the blend point as a first segment of the digital sequence; and means for combining the second digital frame with a second set of samples derived from the first digital frame and the blend point, with emphasis on the second set in a starting sample and emphasis on the second digital frame in an ending sample to produce a second segment of the digital sequence.
Claim 18
Dependent Claim 154 words
The apparatus of claim 10, wherein the means for determining includes: first means for computing an extended frame comprising a discontinuity-smoothed concatenation of the first digital frame with a replica of the first digital frame; second means for finding a subset of the extended frame with a minimum average magnitude difference between the samples in the subset and the second digital frame, and defining the blend point as a first sample in the subset; and wherein the blending means includes: means for supplying a first set of samples derived from the first digital frame and the blend point as a first segment of the digital sequence; and means for combining the second digital frame with the subset of the extended frame, with emphasis on the subset of the extended frame in a starting sample and emphasis on the second digital frame in an ending sample to produce a second segment of the digital sequence.
Claim 19
Dependent Claim 29 words
The apparatus of claim 16, wherein the first and second digital frames represent endings and beginnings respectively of adjacent diphones in speech, and the transducer means produces synthesized speech.
Claim 20
Independent Claim 233 words
An apparatus for synthesizing speech in response to a text, comprising: means for translating text to a sequence of sound segment codes; means, responsive to sound segment codes in the sequence, for decoding the sequence of sound segment codes to produce strings of digital frames of a plurality of samples representing sounds for respective sound segment codes in the sequence, wherein the identified strings of digital frames have beginnings and endings; means for concatenating a first digital frame at the ending of an identified string of digital frames of a particular sound segment code in the sequence with a second digital frame at the beginning an identified string of digital frames of an adjacent sound segment code in the sequence to produce a speech data sequence, including a buffer store to store the samples of first and second digital frames; means, coupled to the buffer store, for determining a blend point for the first and second digital frames in response to magnitudes of samples in the first and second digital frames; and blending means, coupled with the buffer store and the means for determining, for computing a digital sequence representing a concatenation of the first and second sound segments in response to the first frame, the second frame and the blend point; and an audio transducer, coupled to the means for concatenating, to generate synthesized speech in response to the speech data sequence.
Claim 21
Independent Claim 233 words
An apparatus for synthesizing speech in response to a text, comprising: means for translating text to a sequence of sound segment codes; means, responsive to sound segment codes in the sequence, for decoding the sequence of sound segment codes to produce strings of digital frames of a plurality of samples representing sounds for respective sound segment codes in the sequence, wherein the identified strings of digital frames have beginnings and endings; means for concatenating a first digital frame at the ending of an identified string of digital frames of a particular sound segment code in the sequence with a second digital frame at the beginning an identified string of digital frames of an adjacent sound segment code in the sequence to produce a speech data sequence, including a buffer store to store the samples of first and second digital frames; means, coupled to the buffer store, for determining a blend point for the first and second digital frames in response to magnitudes of samples in the first and second digital frames; and blending means, coupled with the buffer store and the means for determining, for computing a digital sequence representing a concatenation of the first and second sound segments in response to the first frame, the second frame and the blend point; and an audio transducer, coupled to the means for concatenating, to generate synthesized speech in response to the speech data sequence.
Claim 22
Dependent Claim 31 words
The apparatus of claim 18, further including: means, responsive to the sound segment codes for adjusting pitch and duration of the identified strings of digital frames in the speech data sequence.
Claim 23
Dependent Claim 56 words
The apparatus of claim 18, wherein the means for determining includes: first means for computing an extended frame in response to the first digital frame; second means for finding a subset of the extended frame which provides an optimum match to the second digital frame, and defining the blend point as a sample in the subset.
Claim 24
Dependent Claim 25 words
The apparatus of claim 20, wherein the extended frame comprises a concatenation of the first digital frame with a replica of the first digital frame.
Claim 25
Dependent Claim 46 words
The apparatus of claim 20, wherein the subset of the extended frame which matches the second digital frame relatively well comprises a subset with a minimum average magnitude difference over the samples in the subset, and the blend point comprises a first sample in the subset.
Claim 26
Dependent Claim 74 words
The apparatus of claim 18, wherein the means for determining includes: first means for computing an extended frame comprising a discontinuity-smoothed concatenation of the first digital frame with a replica of the first digital frame; second means for finding a subset of the extended frame with a minimum average magnitude difference between the samples in the subset and the second digital frame, and defining the blend point as a first sample in the subset.
Claim 27
Dependent Claim 90 words
The apparatus of claim 18, wherein the blending means includes: means for supplying a first set of samples derived from the first digital frame and the blend point as a first segment of the digital sequence; and means for combining the second digital frame with a second set of samples derived from the first digital frame and the blend point, with emphasis on the second set in a starting sample and emphasis on the second digital frame in an ending sample to produce a second segment of the digital sequence.
Claim 28
Dependent Claim 154 words
The apparatus of claim 18, wherein the means for determining includes: first means for computing an extended frame comprising a discontinuity-smoothed concatenation of the first digital frame with a replica of the first digital frame; second means for finding a subset of the extended frame with a minimum average magnitude difference between the samples in the subset and the second digital frame, and defining the blend point as a first sample in the subset; and wherein the blending means includes: means for supplying a first set of samples derived from the first digital frame and the blend point as a first segment of the digital sequence; and means for combining the second digital frame with the subset of the extended frame, with emphasis on the subset of the extended frame in a starting sample and emphasis on the second digital frame in an ending sample to produce a second segment of the digital sequence.
Claim 29
Dependent Claim 30 words
The apparatus of claim 18, wherein the sound segment codes represent speech diphones, and the first and second digital frames represent endings and beginnings respectively of adjacent diphones in speech.

References Cited (Backward Citations)

US4384169A Cited
US4692941A Cited
US4852168A Cited
US5153913A Cited
US5327498A Cited
US5220629A Cited

USPTO Annuity & Maintenance Windows

Annuity Stage Window Opens Payment Deadline Surcharge Period Until Estimated Fee Status
3.5 Years (Year 4) 1999-02-05 1999-08-07 2000-02-06 $2000.00 Window Closed / Lapsed
7.5 Years (Year 8) 2003-02-05 2003-08-07 2004-02-06 $3760.00 Window Closed / Lapsed
11.5 Years (Year 12) 2007-02-05 2007-08-07 2008-02-06 $7700.00 Window Closed / Lapsed

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