Development of Concatenative Syllable-Based Text to Speech Synthesis System for Tamil

Abstract

This paper addresses the problem of improving the intelligibility of the synthesized speech in Tamil text-to-speech (TTS) synthesis system. The human speech is artificially generated by speech synthesis. The normal language text will be automatically converted into speech using TTS system. This paper deals with a corpus-driven Tamil TTS system based on the concatenative synthesis approach. Concatenative speech synthesis involves the concatenation of the basic units to synthesize an intelligent, natural sounding speech. In this paper, syllables are the basic unit of speech synthesis database and the modification of syllable pitch by timescale modification. The speech units are annotated with associated prosodic information about each unit, manually or automatically, based on an algorithm. An annotated speech corpus utilizes the clustering technique that provides way to select the suitable unit for concatenation, depending on the minimum total joint cost of the speech unit. The entered text file is analyzed first, this syllabication is performed based on the linguistics rules, and the syllables are stored separately. Then, the syllable corresponding speech file is concatenated and the silence present in the concatenated speech is removed. After that, discontinuities are minimized at syllable boundaries without degrading the quality. Smoothing at the concatenated syllable boundary is performed, changing the syllable pitches by timescale modification.