Third International Conference on Spoken Language Processing (ICSLP 94)

Yokohama, Japan
September 18-22, 1994

Speech Recognition With Rapid Environment Adaptation by Spectrum Equalization

Keizaburo Takagi, Hiroaki Hattori, Takao Watanabe

Information Technology Research Laboratories, NEC Corporation, Kawasaki, Japan

This paper proposes a rapid environment adaptation algorithm based on spectrum equalization (REALISE). In practical speech recognition applications, differences between training and testing environments often seriously diminish recognition accuracy. These environmental differences can be classified into two types of difference: difference in additive noise and in multiplicative noise in the spectral domain. The proposed method calculates time-alignment between a testing utterance and the closest reference pattern to it, and then calculates the noise differences between the two according to the time-alignment. Then, we adapt all reference patterns to the testing environment using the differences. Finally, the testing utterance is recognized using the adapted reference patterns. In a 250 Japanese word recognition task, in which the training and testing microphones were of two different types, REALISE improved recognition accuracy from 87% to 96%.

Full Paper

Bibliographic reference.  Takagi, Keizaburo / Hattori, Hiroaki / Watanabe, Takao (1994): "Speech recognition with rapid environment adaptation by spectrum equalization", In ICSLP-1994, 1023-1026.