4th International Conference on Spoken Language Processing
Philadelphia, PA, USA
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.
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.