The speech synthesizer component of the Newton text-to-speeech software. MacinTalk provides a flexible codec which converts recognized text into spoken audio. The synthesized speech can be controlled through various parameters such as voice type, speaking rate, volume, and pitch.
MacinTalk first appeared as part of the operating system in the original Macintosh, hence the name.
Newton Underground: How to Work with the Text-to-Speech Extension
Newton Underground: More Newton Text to Speech