for reading out texts in many languages (including Hindi), there is
The authors provide it for many platforms.
Searching on the web, I have found a Ruby interface for the Japanese
version of MBROLA.
Essentially, it involves constructing a file of phonemes (or sounds)
(that’s a combination of two sounds). This is what you have to do for
This file does some adaptation of a text that you want to read out, such
numbers to words.
I haven’t tested the Ruby program (as I don’t speak Japanese, I can’t
anyway), but maybe it can be adapted to your needs.
I think you’d also find the authors of MBROLA helpful - they’ll
for some additional Indian languages profiles.