Composite phoneme units for the speech synthesis of Japanese

Japanese speech synthesis techniques based on composite phoneme units are surveyed. Japanese is an open-syllable language, and there are no consonant clusters in its phonemic system. Japanese is therefore structured with simple and basic syllables of a CV-type, and these are widely used in Japanese speech synthesis-by-rule instead of single phonemes. Other composite syllabic units such as VCV or CVC are also used in Japanese speech synthesis to achieve coarticulatory characteristics. In this paper, a speech synthesis method using CVC units with excitation waveform elements is described as an attempt to improve the quality of synthetic speech.