Significance of vowel epenthesis in Telugu text-to-speech synthesis

Unit selection synthesis inventories have coverage issues, which lead to missing syllable or diphone units. In the conventional back-off strategy of substituting the missing unit with approximate unit(s), the rules for approximate matching are hard to derive. In this paper we propose a back-off strategy for Telugu TTS systems emulating native speaker intuition. It uses reduced vowel insertion in complex consonant clusters to replace missing units. The inserted vowel identity is determined using a rule-set adapted from L2 (second language) acquisition research in Telugu, reducing the effort required in preparing the rule-set. Subjective evaluations show that the proposed back-off method performs better than the conventional methods.