Analysis and synthesis of fundamental frequency contours of Standard Chinese using the command-response model

While the tonal characteristics of Chinese syllables have been qualitatively described in traditional phonetics, quantitative analysis requires a mathematical model. This paper presents such a model for the fundamental frequency contours of Standard Chinese, based on an extension of a model that has already been proved to be applicable to non-tone languages including Japanese, English, and others. The model allows one to interpret a given fundamental frequency contour in terms of tone commands and phrase commands, and to analyze various tonal phenomena in quantitative terms. The paper then describes the results of analysis of fundamental frequency contours of a number of utterances, revealing systematic relationships between the timing of the tone commands and the final of each syllable. The results are used to derive constraints for tone and phrase command generation in speech synthesis. The validity of the rules is confirmed by evaluating the naturalness of prosody of synthetic speech. The validity of introducing these constraints in speech synthesis of Standard Chinese is confirmed by perceptual tests on naturalness of prosody as well as on intelligibility of tones, using speech synthesized with and without these constraints.