Hidden-Markov-model based statistical parametric speech synthesis for Marathi with optimal number of hidden states

Hidden Markov Model and Deep Neural Networks based Statistical Parametric Speech Synthesis systems, gain a significant attention from researchers because of their flexibility in generating speech waveforms in diverse voice qualities as well as in styles. This paper describes HMM-based speech synthesis system (SPSS) for the Marathi language. In proposed synthesis method, speech parameter trajectories used for synthesis are generated from the trained hidden Markov models (HMM). We have recorded our database of 5300 phonetically balanced Marathi sentences to train the context-dependent HMM with five, seven and nine hidden states. The subjective quality measures (MOS and PWP) shows that the HMMs with seven hidden states are capable of giving an adequate quality of synthesized speech as compared to five state and with less time complexity than seven state HMMs. The contextual features used for experimentation are inclusive of a position of an observed phoneme in a respective syllable, word, and sentence.