Quantitative intonation modeling of interrogative sentences for Mandarin speech synthesis

Previous intonational research on Mandarin has mainly focused on the prosody modeling of statements or the prosody analysis of interrogative sentences. To support related speech technologies, e.g., Text-to-Speech, the quantitative modeling of intonation of interrogative sentences with a large-scale corpus still deserves attention. This paper summarizes our work on the quantitative prosody modeling of interrogative sentence in Mandarin. A large-scale natural speech corpus was used in this study. By extracting the pitch contours and fitting the intonation curves, we found that F0 declination and final lowering both existed in interrogative sentences, while they were claimed to be absent in Mandarin in some previous studies. In addition, the declination function could be modeled linearly, and the bearing unit of final lowering in Mandarin was found to be the last prosodic word in the utterance, regardless of its length, rather than a fixed duration range. It was argued in this study that the difference between this finding and the commonly believed rising intonation of the interrogative sentences resulted from the nonlinear relationship between prosody production and perception. The underlying mechanism for the existence of F0 declination and final lowering in interrogative sentences is also discussed.