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US5485543A Expired / Lapsed US ⏱️ 0.0 years remaining

Method and apparatus for speech analysis and synthesis by sampling a power spectrum of input speech

Assignee: Canon Inc
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Filing: 1994-06-08
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Granted: 1996-01-16
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Expires: 2014-06-08
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Abstract

Abstract A method for speech analysis and synthesis for obtaining synthesized speech of a high quality includes the steps of determining a short-period power spectrum by performing an FFT operation on a speech wave, sampling the spectrum at the positions corresponding to the multiples of a basic frequency, applying a cosine polynomial model to the thus obtained sample points to determine the spectrum envelope thereat, then calculating the mel cepstrum coefficients from the spectrum envelope, and effecting speech synthesis, utilizing the mel cepstrum coefficients as the filter coefficients in a synthesizing (logarithmic mel spectrum approximation) filter.

Inventors

  • 👤 Takashi Aso

Bibliographic Details

Application Number —
Jurisdiction US
Data Source google_patents
Last Synchronized 2026-11-03 09:30
CPC Classifications
G; G10; G10L; G10L13/00; G10L13/02

Claims Analysis

Total Claims: 14
Claim 1
Independent Claim 93 words
A method for speech analysis and synthesis comprising the steps of: sampling a short-period power spectrum of speech input into an apparatus with a sampling frequency to obtain sample points, said sampling frequency being controlled so as to trace a basic frequency of input voiced speech: applying a cosine polynomial model to the thus obtained sample points to determine a spectrum envelope; calculating mel cepstrum coefficients from the spectrum envelope; and effecting speech synthesis utilizing the mel cepstrum coefficients as filter coefficients of a mel logarithmic spectrum approximation filter used for speech synthesis.
Claim 2
Independent Claim 93 words
A method for speech analysis and synthesis comprising the steps of: sampling a short-period power spectrum of speech input into an apparatus with a sampling frequency to obtain sample points, said sampling frequency being controlled so as to trace a basic frequency of input voiced speech: applying a cosine polynomial model to the thus obtained sample points to determine a spectrum envelope; calculating mel cepstrum coefficients from the spectrum envelope; and effecting speech synthesis utilizing the mel cepstrum coefficients as filter coefficients of a mel logarithmic spectrum approximation filter used for speech synthesis.
Claim 3
Dependent Claim 41 words
A method according to claim 1, wherein said calculating step comprises the step of converting the frequency axis of the spectrum envelope into a mel approximation scale and applying an inverse Fast Fourier Transform operation to the mel logarithmic spectrum envelope.
Claim 4
Dependent Claim 38 words
A method according to claim 1, wherein said calculating step comprises the step of applying an inverse Fast Fourier Transform process to the spectrum envelope to determine the cepstrum coefficients and applying regressive equations on the cepstrum coefficients.
Claim 5
Dependent Claim 14 words
A method according to claim 3, wherein said regressive equations comprise following equations: ##EQU7##
Claim 6
Independent Claim 130 words
A method for speech analysis comprising the steps of: inputting a speech wave form into an apparatus; extracting a power spectrum from the speech wave form inputted in said inputting step; extracting pitch information of the input voiced speech from the power spectrum extracted in said power spectrum extracting step; sampling the power spectrum extracted in said power spectrum extracting step with a sampling interval to produce sample data, said sampling interval being controlled so as to vary in accordance with a pitch interval of the input voiced speech extracted in said pitch information extracting step; generating a spectrum envelope from the sample data obtained in said sampling step; and transmitting the kind of the voiced speech, the pitch information and said spectrum envelope as parameters of the input speech.
Claim 7
Independent Claim 130 words
A method for speech analysis comprising the steps of: inputting a speech wave form into an apparatus; extracting a power spectrum from the speech wave form inputted in said inputting step; extracting pitch information of the input voiced speech from the power spectrum extracted in said power spectrum extracting step; sampling the power spectrum extracted in said power spectrum extracting step with a sampling interval to produce sample data, said sampling interval being controlled so as to vary in accordance with a pitch interval of the input voiced speech extracted in said pitch information extracting step; generating a spectrum envelope from the sample data obtained in said sampling step; and transmitting the kind of the voiced speech, the pitch information and said spectrum envelope as parameters of the input speech.
Claim 8
Independent Claim 98 words
An apparatus for speech analysis and synthesis comprising: means for sampling a short-period power spectrum of speech input into said apparatus with a sampling frequency to obtain sample points, said sampling frequency being controlled so as to trace a basic frequency of input voiced speech; means for applying a cosine polynomial model to the thus obtained sample points to determine a spectrum envelope; means for calculating mel cepstrum coefficients from the spectrum envelope; and means for effecting speech synthesis utilizing the mel cepstrum coefficients as filter coefficients of a mel logarithmic spectrum approximation filter used for speech synthesis.
Claim 9
Independent Claim 98 words
An apparatus for speech analysis and synthesis comprising: means for sampling a short-period power spectrum of speech input into said apparatus with a sampling frequency to obtain sample points, said sampling frequency being controlled so as to trace a basic frequency of input voiced speech; means for applying a cosine polynomial model to the thus obtained sample points to determine a spectrum envelope; means for calculating mel cepstrum coefficients from the spectrum envelope; and means for effecting speech synthesis utilizing the mel cepstrum coefficients as filter coefficients of a mel logarithmic spectrum approximation filter used for speech synthesis.
Claim 10
Dependent Claim 40 words
An apparatus according to claim 6, wherein said calculating means comprises means for converting the frequency axis of the spectrum envelope into a mel approximation scale and applying an inverse Fast Fourier Transform operation of the mel logrithmic spectrum envelope.
Claim 11
Dependent Claim 37 words
An apparatus according to claim 6, wherein said calculating means comprises means for applying an inverse Fast Fourier Transform process to the spectrum envelope to determine the cepstrum coefficients and applying regressive equations of the cepstrum coefficients.
Claim 12
Dependent Claim 14 words
An apparatus according to claim 8, wherein said regressive equations comprise following equations: ##EQU8##
Claim 13
Independent Claim 138 words
An apparatus for speech analysis comprising: means for inputting a speech wave form into an apparatus; means for extracting a power spectrum from the speech wave form inputted by said inputting means; means for extracting pitch information of the input voiced speech from the power spectrum extracted by said power spectrum extracting means; means for sampling the power spectrum extracted by said power spectrum means with a sampling interval to produce sample data, said sampling interval being controlled so as to vary in accordance with a pitch interval of the input voiced speech extracted by said pitch information extracting means; means for generating a spectrum envelope from the sample data obtained by said sampling means; and means for transmitting the kind of the voiced speech, the pitch information and said spectrum envelope as parameters of the input speech.
Claim 14
Independent Claim 138 words
An apparatus for speech analysis comprising: means for inputting a speech wave form into an apparatus; means for extracting a power spectrum from the speech wave form inputted by said inputting means; means for extracting pitch information of the input voiced speech from the power spectrum extracted by said power spectrum extracting means; means for sampling the power spectrum extracted by said power spectrum means with a sampling interval to produce sample data, said sampling interval being controlled so as to vary in accordance with a pitch interval of the input voiced speech extracted by said pitch information extracting means; means for generating a spectrum envelope from the sample data obtained by said sampling means; and means for transmitting the kind of the voiced speech, the pitch information and said spectrum envelope as parameters of the input speech.

References Cited (Backward Citations)

US4885790A Cited

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