Structural Modeling of Fundamental Frequency contour for Thai Tones

Problem statement: In Thai, tone is an essential feature of a prosodic syllable to identify the meanings of that syllable or that part of word. To generate the tonal speech with natural prosody, it is needed to manage the fundamental frequency (F0) of the speech appropriately. A successful approach of structural modeling from Mandarin Chinese has been adapted to model Thai tone. Approach: The structural modeling of voice F0 contours for Thai tones has been studied. Both male and female speech are concerned. The speech material covers 15 syllables with 5 tones. We use 30 samples for each syllable. The structural modeling parameters for all tones are extracted. Thereafter, the Root Mean Square (RMS) error between the re-synthesized F0 contour and the natural F0 contour is calculated. Results: The experimental analysis shows that RMS errors of all tones are mutually different. It has been noticed that the tone 1 or low tone has the smallest error among all tones in average. Conclusion: The structural model is effectively applied to model Thai tones. The structural modeling can distinguish each tone empirically.