LATENT DIRICHLIET LANGUAGE MODEL FOR SPEECH RECOGNITION

Latent Dirichlet allocation (LDA) has been successfully presented for document modeling and classification. LDA calculates the document probability based on bag-of-words scheme without considering the sequence of words. This model discovers the topic structure at document level, which is different from the concern of word prediction in speech recognition. In this paper, we present a new latent Dirichlet language model (LDLM) for modeling of word sequence. A new Bayesian framework is introduced by merging the Dirichlet priors to characterize the uncertainty of latent topics of n-gram events. The robust topic-based language model is established accordingly. In the experiments, we implement LDLM for continuous speech recognition and obtain better performance than probabilistic latent semantic analysis (PLSA) based language method.