Guix

Sonic implements a simple algorithm for speeding up or slowing down speech. However, it's optimized for speed ups of over 2X, unlike previous algorithms for changing speech rate. Sonic is a C library designed to be easily integrated into streaming voice applications such as text-to-speech (TTS) back ends.

The primary motivation behind Sonic is to enable the blind and visually impaired to improve their productivity with speech engines, like eSpeak. Sonic can also be used by the sighted.