A bi-lingual Thai-English TTS system on Android mobile devices

This paper presents a bi-lingual Thai-English text-to-speech synthesis (TTS) system on Android mobile devices. The system deploys a Thai text processor and a well-known open-source English text processor, which can analyzes English text at high intelligibility. With hidden Markov model (HMM) based speech unit and audio streaming optimization, it can synthesize highly smoothed sounds at a fast response. This paper reveals the optimization of important components. Conditional random fields (CRF) successfully used in Thai word segmentation and a syllable-pattern based statistical modeling for Thai grapheme-to-phoneme conversion are assessed. Several types of speech parameters are compared for best performance. The optimized system produced as high as 3.68 mean opinion score (MOS) with response less than 2 seconds on both high and low specification devices.