SPEECH RECOGNITION APPARATUS BASED ON CEPSTRUM FEATURE VECTOR AND METHOD THEREOF
First Claim
1. A speech recognition apparatus based on a cepstrum feature vector, comprising:
- a reliability estimating unit configured to estimate reliability of a time-frequency segment from an input voice signal;
a reliability reflecting unit configured to reflect the reliability of the time-frequency segment to a normalized cepstrum feature vector extracted from the input speech signal and a cepstrum average vector included for each state of an HMM (Hidden Marcov Model) in decoding;
a cepstrum transforming unit configured to transform the cepstrum feature vector and the average vector in which the reliability is reflected, through a discrete cosine transformation matrix and calculate a transformed cepstrum vector; and
an output probability calculating unit configured to calculate an output probability value of time-frequency segments of the input speech signal by applying the transformed cepstrum vector to the cepstrum feature vector and the average vector in which the reliability is reflected.
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Abstract
A speech recognition apparatus, includes a reliability estimating unit configured to estimate reliability of a time-frequency segment from an input voice signal; and a reliability reflecting unit configured to reflect the reliability of the time-frequency segment to a normalized cepstrum feature vector extracted from the input speech signal and a cepstrum average vector included for each state of an HMM in decoding. Further, the speech recognition apparatus includes a cepstrum transforming unit configured to transform the cepstrum feature vector and the average vector through a discrete cosine transformation matrix and calculate a transformed cepstrum vector. Furthermore, the speech recognition apparatus includes an output probability calculating unit configured to calculate an output probability value of time-frequency segments of the input speech signal by applying the transformed cepstrum vector to the cepstrum feature vector and the average vector.
19 Citations
12 Claims
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1. A speech recognition apparatus based on a cepstrum feature vector, comprising:
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a reliability estimating unit configured to estimate reliability of a time-frequency segment from an input voice signal; a reliability reflecting unit configured to reflect the reliability of the time-frequency segment to a normalized cepstrum feature vector extracted from the input speech signal and a cepstrum average vector included for each state of an HMM (Hidden Marcov Model) in decoding; a cepstrum transforming unit configured to transform the cepstrum feature vector and the average vector in which the reliability is reflected, through a discrete cosine transformation matrix and calculate a transformed cepstrum vector; and an output probability calculating unit configured to calculate an output probability value of time-frequency segments of the input speech signal by applying the transformed cepstrum vector to the cepstrum feature vector and the average vector in which the reliability is reflected. - View Dependent Claims (2, 3, 4, 5, 6)
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7. A speech recognition method based on a cepstrum feature vector, comprising:
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estimating reliability of a time-frequency segment from an input voice signal; normalizing a cepstrum feature vector extracted from the input voice signal; reflecting the reliability of the time-frequency segment to a cepstrum average vector included for each state of an HMM in decoding of the input voice signal; transforming the cepstrum feature vector and the average vector where the reliability is reflected, through a discrete cosine transformation matrix and calculating a transformed cepstrum vector; and calculating an output probability value of time-frequency segments of the input speech signal by applying the transformed cepstrum vector to the cepstrum feature vector and the average vector in which the reliability is reflected. - View Dependent Claims (8, 9, 10, 11, 12)
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Specification