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Speech Synthesis
Aproved by Voice Software Organization


FreeTTS is a speech synthesis system written entirely in the JavaTM programming language. It is based upon Flite: a small run-time speech synthesis engine developed at Carnegie Mellon University. Flite is derived from the Festival Speech Synthesis System from the University of Edinburgh and the FestVox project from Carnegie Mellon University.


This release of FreeTTS includes:

  • Core speech synthesis engine
  • Support for a number of voices:
    • an 8khz diphone, male, US English voice
    • a 16khz diphone, male US English voice
    • a 16khz limited domain, male US English voice
  • Support for importing voices from FestVox (US English only)
  • Specific support for importing CMU ARCTIC voices from FestVox (US English only)
  • Support for MBROLA voices (downloaded separately):
    • a 16khz female, US English voice
    • two 16khz male US English voices
  • Partial support for JSAPI 1.0
  • Extensive API documentation
  • Several demo applications

Review #1

Aproved by Voice Software Organization
Festival Speech Synthesis System

Festival Speech Synthesis System


Festival offers a general framework for building speech synthesis systems as well as including examples of various modules. As a whole it offers full text to speech through a number APIs: from shell level, though a Scheme command interpreter, as a C++ library, from Java, and an Emacs interface. Festival is multi-lingual (currently English (British and American), and Spanish) though English is the most advanced. Other groups release new languages for the system. And full tools and documentation for build new voices are available through Carnegie Mellon’s FestVox project (

The system is written in C++ and uses the Edinburgh Speech Tools Library for low level architecture and has a Scheme (SIOD) based command interpreter for control. Documentation is given in the FSF texinfo format which can generate, a printed manual, info files and HTML.

Festival is free software. Festival and the speech tools are distributed under an X11-type licence allowing unrestricted commercial and non-commercial use alike.




A beta version of 2.0 (labelled 1.95-beta) is available for download. This is the most recent version available for free and unrestricted use. This version is functionally equivalent to 2.0, but we are holding back changing the number to 2.0 until we can accommodate compatibility with newer versions of compilers. New in this release are:

  • HTS hidden Markov model based synthesis engine from Nagoya Institute of Technology.
  • Multisyn general purpose unit selection synthesis engine from CSTR
  • support for gcc 3.2 and 3.3, and intel 8.0
  • clunits unit selection improvements
  • Apple OS X support
  • bug fixes galore.

Other features include:

  • Backwards compatibility with Festival 1.4.3
  • English (British and American), Spanish and Welsh text to speech
  • Externally configurable language independent modules:
    • phonesets
    • lexicons
    • letter-to-sound rules
    • tokenizing
    • part of speech tagging
    • intonation and duration
  • Waveform synthesizers:
  • diphone based: residual excited LPC (and PSOLA not for distribution)
  • MBROLA database support.
  • distributed under a free X11-type licence
  • generalisation of stats modules, ngram, CART, wfst with viterbi so they can be shared more easily
  • Initial JSAPI support
  • XML load for Relations
  • Portable (Unix) distribution
  • On-line documentation
  • SABLE markup, Emacs, client/server (including Java), scripting interfaces.

Review #1


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