Robust speech recognition based on Viterbi Bayesian predictive classification

In this paper, we investigate a new Bayesian predictive classification (BPC) approach to realize robust speech recognition when there exist mismatches between training and test conditions but no accurate knowledge of the mismatch mechanism is available. A specific approximate BPC algorithm called Viterbi BPC (VBPC) is proposed for both isolated word and continuous speech recognition. The proposed VBPC algorithm is compared with conventional Viterbi decoding algorithm on speaker-independent isolated digit and connected digit string (TIDIGITS) recognition tasks. The experimental results show that VBPC can considerably improve robustness when mismatches exist between training and testing conditions.