Is it possible to modify the tone of the voice?

Dear Mycroft community

Sharing the code is really wonderful! I am not a specialist of TTS but I would like to share a question with the community.

I am working on a robot and the goal is to create postures associated with sounds and voice but the tone of the voice changes according to the posture.

The video below shows examples of postures on which I added sounds and voices (but they are not played by the robot) :

The question I am asking is: is it possible to modify the tone on the TTS system you are proposing? My understanding is that it is a quite difficult question to address and I am eager to have your feedback on this

I know this thread is old. In any case check this out for an answer: