Open Source C Speech Software

eGuideDog project develops free software for the blind. Currently, we focus on WebSpeech, Ekho TTS and WebAnywhere.

Open JTalk is a Japanese text-to-speech synthesis system. This software is released under the Modified BSD license.

SPTK is a suite of speech signal processing tools for UNIX environments, e.g., LPC analysis, PARCOR analysis, LSP analysis, PARCOR synthesis filter, LSP synthesis filter, vector quantization techniques, and other extended versions of them.

hts_engine is software to synthesize speech waveform from HMMs trained by the HMM-based speech synthesis system (HTS). This software is released under the Modified BSD license.

Praat is a speech analysis application and source repository for doing phonetics by computer. It was created by Paul Boersma and David Weenink at the University of Amsterdam. The software lets researchers, linguists, clinicians, teachers, and students analyze, synthesize, manipulate, and annotate speech recordings. It supports acoustic inspection through waveforms, spectrograms, pitch tracks, formants, intensity, and related phonetic measurements. Praat also includes scripting tools for automating repetitive analysis, building custom workflows, and processing larger speech datasets. The project is especially useful for academic phonetics, speech science, language documentation, pronunciation research, and publication-quality speech visualization.

moonshine is an open-source automatic speech recognition toolkit optimized for fast and accurate transcription on edge devices and local environments. The project is designed to enable real-time voice applications such as live transcription, voice commands, and embedded speech interfaces without requiring heavy cloud infrastructure. Its architecture emphasizes low latency and flexible input handling, allowing audio streams of varying durations rather than relying on fixed processing windows. Moonshine supports multiple platforms including mobile, desktop, and embedded systems, and provides example projects to accelerate integration into real-world products. The toolkit also includes specialized model variants, including monolingual options that improve accuracy for specific languages. Overall, moonshine serves developers building privacy-conscious, on-device voice interfaces that demand high performance with minimal resource overhead.

Source code from the Research Institute for Signals, Systems and Computational Intelligence http://fich.unl.edu.ar/sinc

a tool for segmenting, labeling and transcribing speech

Software for speech recognition in English & Polish languages. Basic versions of SkryBot: 1. SkryBot Home Speech (English Language) - https://sourceforge.net/projects/skrybotdomowy/files/ReleasesEnglish/InstalatorSkryBotHomeSpeechDemo-2.6.9.18117.exe/download 2. SkryBot DoMowy (Polish Language) - https://sourceforge.net/projects/skrybotdomowy/files/ReleasesPolish/InstalatorSkryBotDoMowyDemo-2.4.9.18117.exe/download More help: https://sourceforge.net/p/skrybotdomowy/wiki/ Domain advanced versions (Polish Language) 1. SkryBot Prawo - for judicial professionals. 2. SkryBot Administracyjny - for civil and government administration. 3. SkryBot Medycyna Rodzinna - for physicians Professional version of SkryBot (commercial) offers you: 1. Audio conversion and cutting sound files into smaller ones. 2. Searching for words or phrases in sound files (recognized by SkryBot). 3. Editing sound files and automatic cutting off long silence parts in audio file.

The Open VXI VoiceXML interpreter is a portable open source library that interprets the VoiceXML dialog markup language. It is designed to serve as a reference for parties interested in understanding how VoiceXML markup might be executed.

Unofficial fork of the GyachE (www.phrozensmoke.com), intended for bug-fixes and further development.

Text-to-Speech conversor for Basque and Spanish. It includes linguistic processing and built voices for the languages aforementioned. Its acoustic engine is based on hts_engine and it uses a high quality vocoder called AhoCoder. Developed by Aholab Signal Processing Laboratory: https://aholab.ehu.es/aholab/ http://aholab.ehu.es/ahocoder/

The project provides a ready-to-use interface for the julius CSR engine for a handicapped child which is not able to use the keyboard well. It integrates into X11 and Windows. Find out how you can help: http://simon-listens.org/index.php?support

Winboard 4.5 32-bit is a free Windows accessible Chess program that works automatically with the JAWS or the free NVDA screen reader. It is for the blind, low sighted or those who can not use a mouse. It provides vocal announcements of position changes and other selectable board conditions. Blind players also use a separate "tactile chess board". Winboard 4.5 has full keyboard access to move pieces and run menu items. Partial sighted players use high contrast mode and adjust board, piece, most font sizes and colors. Available languages are English, German, Spanish, Italian, Dutch and Russian. Games may be viewed, modified or saved in standard PGN format. Two Chess engines supply play and grand master strength move analysis. Connect to the Free Internet Chess Server (FICS) and play humans. Modify verbosity in screen reader configurations and in the Winboard "Sound" dialog under the "General" menu. Find all documentation in the "doc" folder under the Winboard directory of your C drive.

A plugin for pidgin that interfaces with the popular program festival. It allows for instant messages to be spoken by festival so you can hear it through your speakers.

Text-to-Speech conversor for Basque, Spanish, Catalan, Galician and English. It includes linguistic processing and built voices for all the languages aforementioned. Its acoustic engine is based on hts_engine and it uses a high quality vocoder called AhoCoder. Developed by Aholab Signal Processing Laboratory: https://aholab.ehu.es/aholab/ http://aholab.ehu.es/ahocoder/

Speak Freely is a Cross Platform Internet telephony (Voice Chat) application which provides high quality voice grade audio with GSM and CELP compression and encryption with DES, Blowfish, and IDEA ciphers. Refering to recent news: The maintainers will never add any unwanted extra software in the zip download file but we can only speak for our selves.

This de-esser uses a novel approach called Temporal Sibilance Processing. The idea is to distinguish between fricatives and voiced sections of the speech signal by the number of zero crossings in time. Most of the speech file is left untouched (the samples are directly copied from source to destination). Only fricatives that are long enough and loud enough are filtered. The advantage of this approach over traditional approaches is that the clarity of the remaining speech is completely unaffected.

To provide basic text-to-speech capability on as many platforms and for as many spoken languages as possible by formant synthesis from an International Phonetic Alphabet representation.

A patent-free audio codec designed especially for voice (unlike Vorbis which targets general audio) signals and providing good narrowband and wideband quality. This project is complementary to the Ogg Vorbis codec.

Dhvani is Text-to-Speech System for Indic Languages. Current C- GNU/Linux implementation supports Hindi, Kannada, Marathi, Malayalam, Gujarati, Bengali, Telugu, Panjabi, Tamil and Oriya.

Advanced Speech Signal Analysis library provides a structure to handle various file formats and a variety of analysis functions commonly used in speech processing.

Automatically translate english/french/german text to german/french/english text and output speech in appropriate language. All Automagically with the power of the inter-webs.

A language teaching program and library based on C. It includes sound snippets featuring native speakers. You can create, edit and use various lessons and learn via an optional GTK2 interface.

Portable GUI Ogg/Speex/FLAC audio encoder/player that can encode wave file and provides additional functionality such as audiofile tagging, html-album generator, cd-ripping, etc. Targeted to be used on Freebsd, Linux and win32 platforms and the frontends