TERAVoice supports the synthesis of speech through Text-To-Speech (TTS) engines. This is done through the Microsoft Speech API 5.1 (SAPI5).
- TERAVoice can use any TTS engine that is compatible with SAPI 5
- TERAVoice does not support TTS engines that are only SAPI 4 compatible
Almost all modern TTS engines for Windows are compatible with SAPI 5.
There are some free TTS engines that are distributed with the Microsoft Agent Runtime. These engines only support SAPI 4 and cannot be used with TERAVoice. There are currently no plans to add support for SAPI 4 because the quality of these (rather old) engines is very low and professional applications would not really benefit.
We rather suggest to use a state-of-the-art TTS engine.
A list of SAPI 5 compliant engines can be found on the following page: