American Journal of Applied Sciences

A Control of Fundamental Frequency Contour for Hidden Markov Model-Based Thai Speech Synthesis

Suphattharachai Chomphan

DOI : 10.3844/ajassp.2012.259.264

American Journal of Applied Sciences

Volume 9, Issue 2

Pages 259-264


Problem statement: In the conventional HMM-based speech synthesis system for Thai, there is no control of fundamental frequency control in the synthesis stage. The tone correctness of the synthesized speech is unacceptable due to the imbalance of training data of all tones. Approach: This study proposes a mathematical model to control the F0 contour of the synthesized speech. This control is proposed to correct only some distorted segments of the F0 contour which occur within some syllables due to lacking of training data for some tones. Results: An experimental result compares F0 contours between those of synthesized speech with and without tone-type questions; furthermore the size of Thai speech corpus is varied to investigate the synthesized speech quality. A mathematical model is applied to control the F0 contour. By using the proposed control, the correction of the F0 contour is obviously shown in the experimental results. Conclusion: The control of F0 contour has been proposed. It can noticeably improve the tone correctness of the synthesized speech.


© 2012 Suphattharachai Chomphan. This is an open access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.