Discriminatively trained continuous Hindi speech recognition system using interpolated recurrent neural network language modeling

This paper implements and evaluates the performance of a discriminatively trained continuous Hindi language speech recognition system. The system uses maximum mutual information and minimum phone error discriminative techniques with various numbers of Gaussian mixtures to train the automatic speech recognition (ASR) system. The training dataset consists of Hindi speech transcription. The experiments show a significant performance gain over maximum likelihood-based Hindi language speech recognition system. The system uses an efficient recurrent neural network (RNN)-based language modeling. The results indicate that the use of RNN-based language modeling enhances the performance of the ASR system. Further, the interpolation of n-gram language model (LM) with the RNNLM exhibits an additional increase in recognition performance of the implemented system. The proposed system introduces the concept of speaker adaption using maximum likelihood linear regression technique. The paper also gives an overview of the techniques used for discriminative training along with practical issues involved in their implementation.