Text-to-Speech (TTS) conversion system can convert any words or sentences into speech. To synthesize the speech like human beings, careful prosody control including intonation, duration, accent, and pause is required. It helps listencrs understand the speech clearly and makes the speech sound more natural. In this thesis, an improved prosody control scheme is proposed. Among its factors, intonation, duration, and pause are closely related to syntatic structure, and their relations have been formalized and embodied in TTS. TTS consists of three processing stages ; linguistic processor, prosody controller, and sppech signal synthesizer. The linguistic processor converts text to demisyllables, the fundamental unit for synthesis. The prosody controller determines the pitch frequencies and syllable durations by the control rules proposed in this thesis. The speech signal synthesizer fetches stored parameters corresponding the fundamental units and synthesizes the speech by driving the cepstral digital filter. To evaluate the synthesized speech with the proposed prosody control, one of the subjective evaluation methods-MOS(Mean Opinion Score) method has been used. Synthesized speech has been tested on 10 listeners and each listener scored the speech between 1 and 5. Through the evaluation experiments, it is observed that the proposed prosody control helps TTS system synthesize the more natural speech.
