The eSpeak NG is a compact open source software text-to-speech synthesizer for Linux, Windows, Android and other operating systems. It supports more than 100 languages and accents. It is based on the eSpeak engine created by Jonathan Duddington.
eSpeak NG uses a "formant synthesis" method. This allows many languages to be provided in a small size. The speech is clear, and can be used at high speeds, but is not as natural or smooth as larger synthesizers which are based on human speech recordings. It also supports Klatt formant synthesis, and the ability to use MBROLA as backend speech synthesizer.
eSpeak NG is available as:
See the CHANGELOG for a description of the changes in the various releases and with the eSpeak NG project.
The following platforms are supported:
The espeak-ng binaries use the same command-line options as espeak, with
several additions to provide new functionality from espeak-ng such as specifying
the output audio device name to use. The build creates symlinks of
speak_lib.h include file is located in
an optional symlink in
espeak/speak_lib.h. This file contains the espeak 1.48.15
API, with a change to the
ESPEAK_API macro to fix building on Windows
and some minor changes to the documentation comments. This C API is API and ABI
compatible with espeak.
espeak-data data has been moved to
espeak-ng-data to avoid conflicts with
espeak. There have been various changes to the voice, dictionary and phoneme files
that make them incompatible with espeak.
The espeak-ng project does not include the espeakedit program. It has moved
the logic to build the dictionary, phoneme and intonation binary files into the
libespeak-ng.so file that is accessible from the
espeak-ng command line and
The program was originally known as speak and originally written for Acorn/RISC_OS computers starting in 1995 by Jonathan Duddington. This was enhanced and re-written in 2007 as eSpeak, including a relaxation of the original memory and processing power constraints, and with support for additional languages.
In 2010, Reece H. Dunn started maintaining a version of eSpeak on GitHub that was designed to make it easier to build eSpeak on POSIX systems, porting the build system to autotools in 2012. In late 2015, this project was officially forked to a new eSpeak NG project. The new eSpeak NG project is a significant departure from the eSpeak project, with the intention of cleaning up the existing codebase, adding new features, and adding to and improving the supported languages.
The historical branch contains the available older releases of the original eSpeak that are not contained in the subversion repository.
1.24.02 is the first version of eSpeak to appear in the subversion repository, but releases from 1.05 to 1.24 are available at http://sourceforge.net/projects/espeak/files/espeak/.
These early releases have been checked into the historical branch, with the 1.24.02 release as the last entry. This makes it possible to use the replace functionality of git to see the earlier history:
git replace 8d59235f 63c1c019
NOTE: The source releases contain the
windows_sapi folders. These
do not appear in the source repository until later releases, so have
been excluded from the historical commits to align them better with
the 1.24.02 source commit.
eSpeak NG Text-to-Speech is released under the GPL version 3 or later license.
getopt.c compatibility implementation for getopt support on Windows is
taken from the NetBSD
getopt_long implementation, which is licensed under a
2-clause BSD license.
Android is a trademark of Google Inc.