4th International Conference on Spoken Language Processing

Philadelphia, PA, USA
October 3-6, 1996

Estimation of Channel Bias for Telephone Speech Recognition

Jen-Tzung Chien (1), Hsiao-Chuan Wang (1), Lee-Min Lee (2)

(1) Department of Electrical Engineering, National Tsing Hua University, Hsinchu, Taiwan
(2) Department of Electrical Engineering, Mingchi Institute of Technology, Taipei Hsien, Taiwan

In this study, we propose a maximum a posterior (MAP) estimation of channel bias to compensate the channel mismatch in telephone speech recognition. For a telephone speech, the channel bias is estimated by maximizing a posterior probability. Because a posterior probability is composed of a likelihood function and a prior density, we introduce a scale factor to evaluate their weights in MAP estimation. To further improve the performance, a prior channel statistics is extended to multiple components and the channel mismatch is separately compensated for different segments. Besides, a rapid MAP estimation applied in feature domain is also proposed for reducing the computational complexity. Experiments show that proposed method can significantly improve recognition rates and computational complexity.

Full Paper

Bibliographic reference.  Chien, Jen-Tzung / Wang, Hsiao-Chuan / Lee, Lee-Min (1996): "Estimation of channel bias for telephone speech recognition", In ICSLP-1996, 1840-1843.