Learning Mandarin tone mapping codebook for voice conversion

The phonetics properties of Chinese Mandarin features clearly demarcated syllables with tonal phonemes. A tone codebook mapping method is proposed to obtain a better performance in voice conversion of Chinese Mandarin speech than the conventional conversion method, which focuses mainly on the short-time spectral envelopes. The pitch contour of the whole Mandarin syllable is used as a unit type for pitch conversion. The syllable pitch contours are first extracted from the source and target utterances. Time normalization and moving average filtering are then performed on them. These preprocessed pitch contours are classified to generate the source and target tone code-books, and by associating them a Mandarin tone mapping codebook is finally obtained in terms of speech alignment. Experimental results show that the proposed tone codebook mapping method in voice conversion can give a good performance in Chinese Mandarin speech.