5th International Conference on Spoken Language Processing

Sydney, Australia
November 30 - December 4, 1998

Modeling of Variations in Cepstral Coefficients Caused by F0 Changes and its Application to Speech Processing

Nobuaki Minematsu, Seiichi Nakagawa

Toyohashi Univ. of Tech., Japan

Correlation of spectral variations and F0 changes in a vowel is firstly analyzed, where the variations are also compared to VQ distortions calculated in a five-vowel space. It is shown that the F0 change approximately by a half octave produces the spectral variation comparable to the VQ distortion when the codebook size is the number of the vowels. Next, a model to predict the cepstral coefficients' variations caused by the F0 changes is built using the multivariate regression analysis. Experiments show that the generated frame by the model has a remarkably small distance to the target frame. Furthermore, the model is evaluated separately in terms of a spectral envelope predictor with a given F0 and a mapping function of feature sub-spaces. While the models should be built dependently on phonemes and speakers as the former, adequate selection of parameters can enable the speaker/phoneme-independent models to work effectively as the latter.

Full Paper

Bibliographic reference.  Minematsu, Nobuaki / Nakagawa, Seiichi (1998): "Modeling of variations in cepstral coefficients caused by F0 changes and its application to speech processing", In ICSLP-1998, paper 0052.