klattsch began as a browser instrument for typing phonemes and making an old computer voice talk and sing. People shared songs, covers, sound effects, and experiments made with it, so that small instrument grew into a full app.

The app adds text and piano-roll editing, a detailed pitch editor for drawing intonation curves, four switchable synthesis engines, MIDI import, multiple voice parts, backing tracks, detailed voice shaping, and WAV and video export. It works offline on Windows, macOS, Linux, and Android. The free browser version remains available for anyone who wants to hear the voice immediately.

The synthesis follows the Klatt formant-synthesis research lineage associated with classic computer voices. klattsch does not contain DECtalk code and does not try to sound convincingly human. The artificial character is the point.