SPEAKER NORMALIZATION PROCESSOR APPARATUS FOR GENERATING FREQUENCY WARPING FUNCTION, AND SPEECH RECOGNITION APPARATUS WITH SAID SPEAKER NORMALIZATION PROCESSOR APPARATUS

In a speaker normalization processor apparatus, a vocal-tract configuration estimator estimates feature quantities of a vocal-tract configuration showing an anatomical configuration of a vocal tract of each normalization-target speaker, by looking up to a correspondence between vocal-tract configuration parameters and Formant frequencies previously determined based on a vocal tract model of the standard speaker, based on speech waveform data of each normalization-target speaker. A frequency warping function generator estimates a vocal-tract area function of each normalization-target speaker by changing feature quantities of a vocal-tract configuration of the standard speaker based on the feature quantities of the vocal-tract configuration of each normalization-target speaker estimated by the estimation means and the feature quantities of the vocal-tract configuration of the standard speaker, estimating Formant frequencies of speech uttered by each normalization-target speaker based on the estimated vocal-tract area function of each normalization-target speaker, and generating a frequency warping function showing a correspondence between input speech frequencies and frequencies after frequency warping.