Bengali Text to Speech

Habari Bengali kwa lugha

Bengali text-to-speech turns on one fact that trips up voices ported from Hindi: the inherent vowel of the Bengali script is not the open 'a' of Devanagari but a rounded 'ô' sound, so the same abugida logic yields a different default vowel and getting this wrong makes every word sound foreign. On top of that, Bengali has genuine schwa realization rules that decide when the inherent vowel is pronounced as ô, when it becomes o, and when it is dropped, none of which the script spells out explicitly. The Bengali-Assamese script is dense with conjunct consonants (juktakkhor) that fuse two or three letters into a single ligature, and correctly decomposing and pronouncing these clusters is the hardest rendering problem. Bengali largely lacks the aspirated-vowel and tone complications of some neighbours but compensates with vowel harmony tendencies, where the vowel in one syllable influences the next. Because the language spans two countries, a natural voice should handle both the standard of West Bengal and the closely related standard of Bangladesh. Demand is enormous: Bengali news, film and music for both Kolkata and Dhaka audiences, e-learning, accessibility for a very large speaker base, and diaspora media.