A coarticulation model, namely ‘carrier model’, has been proposed previously by Dang et al. to improve the performance of a physiological articulatory model based speech synthesizer. The carrier model offers a good framework to account for coarticulation in the planning stage, while its parameters need to be refined for improving the performance of the model. This study is to refine the parameters of the carrier model and estimate typical phonetic targets by minimizing the differences between model simulations and observations. A simulation based optimization framework is proposed for this purpose. The framework consists of two layers: obtaining planned targets in a low layer; estimating phonetic targets and optimizing the parameters in a high layer. A direct search method was applied to the low layer due to the non-analytic nature of the articulation model, while the high layer adopts bilevel optimization strategy to decompose the complicated problem into a set of subproblems. A general evaluation was conducted by combining the refined carrier model and the learned phonetic targets together using the physiological articulatory model and the average error between observations and simulations was 0.15 cm over 103 VCV combinations on the jaw, tongue tip and tongue dorsum.
Cite as: Wei, J., Lu, X., Dang, J. (2006) A simulation based parameter optimization for a coarticulation model. Proc. Interspeech 2006, paper 1772-Tue1FoP.5, doi: 10.21437/Interspeech.2006-311
@inproceedings{wei06_interspeech,
author={Jianguo Wei and Xugang Lu and Jianwu Dang},
title={{A simulation based parameter optimization for a coarticulation model}},
year=2006,
booktitle={Proc. Interspeech 2006},
pages={paper 1772-Tue1FoP.5},
doi={10.21437/Interspeech.2006-311}
}