2009 Volume 6 Issue 8 Pages 437-442
Because of noise and reverberation, accuracy of speech recognition systems decreases when the distance between talker and microphone increases. In this paper a new method for microphone array processing is proposed in which parameters of array processing are adjusted in calibration phase based on phones used in language and maximum likelihood method. Optimum filter length first studied and then optimized filter parameters are stored and used during recognition phase. A new modified Viterbi algorithm using optimal phone-based filter parameters is introduced for recognition phase. The proposed algorithm is analytically formulated and improvement in recognition accuracy in various noise level and reverberation time is studied.