Abstract: An improved, high-quality Thai text-to-phoneme converter. Syllabification is performed strictly according to the Thai pronunciation rules. Initial vowels, Thai syllable structures, special vowels, leading vowels, syllables with silent marks, unterminated vowels and terminated vowels are used to accurately implement the Thai syllabification. After syllabification, the most probable phonemes are obtained for all of the syllables using a rule-based approach in one embodiment of the invention.