Windows Text-to-Speech Voices on Windows for Telephony

Ditch Microsoft Mary for a professional sounding voice! Cepstral makes it easy to add high quality synthesized speech to your Windows based IVR, Call Center or Unified Communications system.

Asterisk and Cepstral integration via the app_swift module.

Cepstral Telephony Server

The Cepstral Telephony Server contains the Swift TTS engine, lexical preprocessor, and the user lexicon. When combined with one of our voices you have the ability to stream synthesized speech to a single call. Add components to expand the capabilities to create the perfect TTS solution for your Windows telephony system.


Choose a Cepstral TTS voice to power your system. Purchase additional voices to offer multiple language support. Cepstral makes it easy to switch voices during a call.

Port License

Stream audio to multiple, simultaneous calls by purchasing Concurrent Port licenses.

Save to File

Produce static content like IVR menu prompts and extension voicemail messages by saving the TTS audio to a WAV file. Choose from multiple frequencies and audio encodings including 8kHz u-law. Save to File is not designed for use in realtime operation during a call.


Cepstral is SAPI compatible making it a drop-in upgrade for the Microsoft Mary and Anna voices. You can also use the Cepstral API for systems that do not support SAPI or for more direct access to the Swift TTS engine.