A study of prior sensitivity for Bayesian predictive classification based robust speech recognition

We previously introduced a new Bayesian predictive classification (BPC) approach to robust speech recognition and showed that BPC is capable of coping with many types of distortions. We also learned that the efficacy of the BPC algorithm is influenced by the appropriateness of the prior distribution for the mismatch being compensated. If the prior distribution fails to characterize the variability reflected in the model parameters, then the BPC will not help much. In this paper, we show how the knowledge and/or experience of the interaction between speech signal and the possible mismatch guide us to obtain a better prior distribution which improves the performance of the BPC approach.