Speech feature extraction apparatus and speech feature extraction method

A non-transitory computer readable storage medium storing instructions of a computer program which when executed by a computer results in performance of steps comprising:

• extracting speech segments over a predetermined period at intervals of a unit time from an input speech signal to generate a unit speech signal;
• calculating each subband average time corresponding to time required to reach a center of energy gravity of the unit speech signal in each of a plurality of frequency bands obtained by dividing an overall frequency band into a number smaller than a bin number of frequency;
• generating a speech feature in each of the frequency bands based on the subband average time;
• and
• transforming, by a decoder that performs speech recognition processing, the input speech signal into words using the speech feature in the each of the frequency bands, wherein the speech feature is expressed in terms of time.

A speech feature extraction method, comprising:

• controlling a computer to:
• extract speech segments over a predetermined period at intervals of a unit time from an input speech signal to generate a unit speech signal;
• calculate each subband average time corresponding to time required to reach a center of energy gravity of the unit speech signal in each of a plurality of frequency bands obtained by dividing an overall frequency band into a number smaller than a bin number of frequency;
• generate a speech feature in each of the frequency bands based on the subband average time;
• and
• transform, by a decoder that performs speech recognition processing, the input speech signal into words using the speech feature in the each of the frequency bands, wherein the speech feature is expressed in terms of time.

A speech feature extraction method, comprising:

• controlling a computer to:
• extract speech segments over a predetermined period at intervals of a unit time from the plurality of subband input speech signals obtained by extracting signal components of a plurality of frequency bands from the input speech signal to generate a plurality of subband unit speech signals;
• calculate each subband average time corresponding to a center of energy gravity of power of each of the plurality of subband unit speech signals within a predetermined interval;
• generate a speech feature in each of the frequency bands based on the subband average time;
• and
• transform, by a decoder that performs speech recognition processing, the input speech signal into words using the speech feature in the each of the frequency bands, wherein the speech feature is expressed in terms of time.

A non-transitory computer readable storage medium storing instructions of a computer program which when executed by a computer results in performance of steps comprising:

• extracting speech segments over a predetermined period at intervals of a unit time from a plurality of subband input speech signals obtained by extracting signal components of a plurality of frequency bands from an input speech signal to generate a plurality of subband unit speech signals, wherein the plurality of subband input speech signals is obtained from the input speech signal by a band-pass filter;
• calculating each subband average time corresponding to a center of energy gravity of power of each of the plurality of subband unit speech signals within a predetermined interval;
• generating a speech feature in each of the frequency bands based on the subband average time;
• and
• transforming, by a decoder that performs speech recognition processing, the input speech signal into words using the speech feature in the each of the frequency bands, wherein the speech feature is expressed in terms of time.

A speech feature extraction apparatus, comprising:

• a computer programmed to comprise:
• an extraction unit configured to extract speech segments over a predetermined period at intervals of a unit time from the plurality of subband input speech signals obtained by extracting signal components of a plurality of frequency bands from the input speech signal to generate a plurality of subband unit speech signals;
• a calculation unit configured to calculate each subband average time corresponding to a center of energy gravity of power of each of the plurality of subband unit speech signals within a predetermined interval;
• a generation unit configured to generate a speech feature in each of the frequency bands based on the subband average time;
• and
• a decoder performing speech recognition processing to transform the input speech signal into words using the speech feature in the each of the frequency bands, wherein the speech feature is expressed in terms of time.