The CSLU Toolkit was created to provide the basic framework and tools for people to build, investigate and use interactive language systems. These systems incorporate leading-edge speech recognition, natural language understanding, speech synthesis and facial animation.
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. Tools and documentation for build new voices are available through Carnegie Mellon's FestVox project
The Festvox project aims to make the building of new synthetic voices more systemic and better documented, making it possible for anyone to build a new voice. Specifically it offers documentation, including scripts explaining the background and specifics for building new voices for speech synthesis in new and supported languages, aids to building synthetic voices for limited domains, example speech databases to help building new voices, etc.
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.
HMM-Based Speech Synthesis System (HTS)
The basic core system of HTS, available from NITECH, was implemented as a modified version of HTK together with SPTK (see below), and is released as HMM-Based Speech Synthesis System (HTS) in a form of patch code to HTK.
hts_engine is a small run-time synthesis engine (less than 1 MB including acoustic models), which can run without the HTK library. The current version does not include any text analyzer but the Festival Speech Synthesis System can be used as a text analyzer.
KPE provides a graphical interface for the implementation of the Klatt 1980 formant synthesiser. The interface allows users to display and edit Klatt parameters using a graphical display which includes the time-amplitude waveform of both the original speech and its synthetic copy, and some signal analysis facilities. See also the other University College London software.
The aim of the MBROLA project, initiated by the TCTS Lab of the Faculté Polytechnique de Mons (Belgium), is to obtain a set of diphone-based speech synthesizers for as many languages as possible, and provide them free for non-commercial applications.
MARY is a multi-lingual (German, English, Tibetan) and multi-platform (Windows, Linux, MacOs X and Solaris) speech synthesis system. It comes with an easy-to-use installer - no technical expertise should be required for installation. It enables expressive speech synthesis, using both diphone and unit-selection synthesis
Praat is a system for doing phonetics by computer. The computer program Praat is a research, publication, and productivity tool for phoneticians. With it, you can analyse, synthesize, and manipulate speech, and create high-quality pictures for your articles and thesis.
Speech Filing System (SFS)
SFS SFS is a free computing environment for PCs for conducting research into the nature of speech. It comprises software tools, file and data formats, subroutine libraries, graphics, special programming languages and tutorial documentation. It performs standard operations such as acquisition, replay, display and labelling, spectrographic and formant analysis and fundamental frequency estimation.
Speech Signal Processing Toolkit (SPTK)
The main feature of the Speech Signal Processing Toolkit, available from NITECH, is that not only standard speech analysis and synthesis techniques (e.g., LPC analysis, PARCOR analysis, LSP analysis, PARCOR synthesis filter, LSP synthesis filter, and vector quantization techniques) but also speech analysis and synthesis techniques developed at the research group can easily be used.
TrackDraw is a graphical interface for controlling the parameters of a speech synthesizer.
WaveSurfer is a tool for doing speech analysis. The analysis features include formants and pitch extraction and real time spectrograms. The Wavesurfer tool built on top of the Snack speech visualization module, is highly modular and extensible at several levels.