Apparatus and method for recognizing a speech
AssigneeKabushiki Kaisha Toshiba
InventorsYusuke Shinohara, Masami Akamine
Life of this patent
Estimating the term…
Abstract
A noisy vector is extracted from a noisy speech, which is a clean speech on which a noise is superimposed. A noise parameter of the noise is estimated from the noisy vector. A prior distribution parameter of a clean vector of the clean speech is already stored. A joint Gaussian distribution parameter between the clean vector and the noisy vector is calculated by unscented transformation, from the noise parameter and the prior distribution parameter. A posterior distribution parameter of the clean vector is calculated by the joint Gaussian distribution parameter, from the noisy vector. By comparing the posterior distribution parameter with a standard pattern of each word previously stored, a word sequence of the noisy speech is output.
Claims10
An apparatus for recognizing a speech, comprising:
- a feature extraction unit configured to extract a noisy vector from a noisy speech inputted, the noisy speech being a clean speech on which a noise is superimposed;
- a noise estimation unit configured to estimate a noise parameter of the noise from the noisy vector;
- a parameter storage unit configured to store a prior distribution parameter of a clean vector of the clean speech;
- a distribution calculation unit configured to calculate a joint Gaussian distribution parameter between the clean vector and the noisy vector by unscented transformation, from the noise parameter and the prior distribution parameter;
- a calculation execution unit configured to calculate a posterior distribution parameter of the clean vector by the joint Gaussian distribution parameter, from the noisy vector;
- and
- a comparison unit configured to compare the posterior distribution parameter with a standard pattern of each word previously stored, and output a word sequence of the noisy speech based on a comparison result.
A method for recognizing a speech, comprising:
- storing a prior distribution parameter of a clean vector of a clean speech in a memory;
- extracting a noisy vector from a noisy speech inputted, the noisy speech being the clean speech on which a noise is superimposed;
- estimating a noise parameter of the noise from the noisy vector;
- calculating a joint Gaussian distribution parameter between the clean vector and the noisy vector by unscented transformation, from the noise parameter and the prior distribution parameter stored in the memory;
- calculating a posterior distribution parameter of the clean vector by the joint Gaussian distribution parameter, from the noisy vector;
- comparing the posterior distribution parameter with a standard pattern of each word previously stored;
- and
- outputting a word sequence of the noisy speech based on a comparison result.
A computer readable medium storing program codes for causing a computer to recognize a speech, the program codes comprising:
- a first program code to store a prior distribution parameter of a clean vector of a clean speech in a memory;
- a second program code to extract a noisy vector from a noisy speech inputted, the noisy speech being the clean speech on which a noise is superimposed;
- a third program code to estimate a noise parameter of the noise from the noisy vector;
- a fourth program code to calculate a joint Gaussian distribution parameter between the clean vector and the noisy vector by unscented transformation, from the noise parameter and the prior distribution parameter stored in the memory;
- a fifth program code to calculate a posterior distribution parameter of the clean vector by the joint Gaussian distribution parameter, from the noisy vector;
- a sixth program code to compare the posterior distribution parameter with a standard pattern of each word previously stored;
- and
- a seventh program code to output a word sequence of the noisy speech based on a comparison result.
Dependencies are inferred from the claim text.