On Integrating Tonal Information into Chinese Speech Recognition

Reliable pitch detection is important in Chinese speech recognition since Chinese is a tonal language. In this paper, several pitch information integration approaches are investigated. In a noise-free environment, conventional pitch estimators work quite well. In adverse conditions, however, robustness of pitch detection algorithms is still a challenging problem. Our experimental results show that by using pitch information, a performance improvement can be obtained in a clean environment. However, a substantial recognition accuracy degradation is observed in adverse conditions due to the noise sensitivity of pitch estimators. Our experimental results indicate that front-end extracting higher-order cepstral coefficients provides the best results when testing the recognition performance in Chinese.