eSpeak NG Text-to-Speech

• Build Dependencies
  • Debian
• Building
  • Audio Output Configuration
  • eSpeak NG Feature Configuration
  • Extended Dictionary Configuration
• Testing
• Installing
• Building Voices
• Adding New Voices
• Praat Changes
• eSpeak for Android
• Historical Versions
• Bugs
• License Information

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The eSpeak NG (Next Generation) Text-to-Speech program is an open source speech synthesizer that supports over 70 languages. It is based on the eSpeak engine created by Jonathan Duddington. It uses spectral formant synthesis by default which sounds robotic, but can be configured to use Klatt formant synthesis or MBROLA to give it a more natural sound.

Build Dependencies

In order to build eSpeak NG, you need:

1. a functional autotools system (make, autoconf, automake, libtool and pkg-config);
2. a functional c compiler that supports C11.

Optionally, you need:

1. the pulseaudio development library to enable pulseaudio output;
2. the portaudio development library to enable portaudio output.

Debian

Dependency	Install
autotools	sudo apt-get install make autoconf automake libtool pkg-config
c11 compiler	sudo apt-get install gcc
pulseaudio	sudo apt-get install libpulse-dev
portaudio	sudo apt-get install libportaudio-dev

Building

The espeak-ng and speak-ng programs, along with the espeak-ng voices, can be built via the standard autotools commands:

$ ./autogen.sh
$ ./configure --prefix=/usr
$ make

Audio Output Configuration

The following configure options control which audio interfaces to use:

Option	Audio Interfaces	Default
--with-pulseaudio	PulseAudio	yes
--with-portaudio	PortAudio	yes
--with-sada	SADA (Solaris)	no

If pulseaudio and portaudio are both enabled and available, eSpeak NG will choose which one to use at runtime, trying pulseaudio first before falling back to portaudio.

eSpeak NG Feature Configuration

The following configure options control which eSpeak NG features are enabled:

Option	Description	Default
--with-klatt	Enable Klatt formant synthesis.	yes
--with-mbrola	Enable MBROLA voice support.	yes
--with-sonic	Use the sonic library to support higher WPM.	yes
--with-async	Enable asynchronous commands.	yes

Extended Dictionary Configuration

The following configure options control which of the extended dictionary files to build:

Option	Extended Dictionary	Default
--with-extdict-ru	Russian	no
--with-extdict-zh	Mandarin Chinese	no
--with-extdict-zhy	Cantonese	no

The extended dictionaries are taken from http://espeak.sourceforge.net/data/ and provide better coverage for those languages, while increasing the resulting dictionary size.

Testing

Before installing, you can test the built espeak-ng using the following command:

$ ESPEAK_DATA_PATH=`pwd` LD_LIBRARY_PATH=src:${LD_LIBRARY_PATH} src/espeak-ng ...

The ESPEAK_DATA_PATH variable needs to be set to use the espeak-ng data from the source tree. Otherwise, espeak-ng will look in $(HOME) or /usr/share/espeak-data.

The LD_LIBRARY_PATH is set as espeak uses the libespeak-ng.so shared library. This ensures that espeak uses the built shared library in the src directory and not the one on the system (which could be an older version).

Installing

You can install eSpeak NG by running the following command:

$ sudo make LIBDIR=/usr/lib/x86_64-linux-gnu install

The LIBDIR path may be different to the one on your system (the above is for 64-bit Debian/Ubuntu releases that use the multi-arch package structure -- that is, Debian Wheezy or later).

You can find out where espeak-ng is installed to on your system if you already have an espeak-ng install by running:

$ find /usr/lib | grep libespeak-ng

Building Voices

If you are modifying a language's phoneme, voice or dictionary files, you can just build that voice by running:

$ make <lang-code>

For example, if you add entries in the dictsource/en_extra file, you can run:

$ make en

to build an English voice file with those changes in without rebuilding all the voices. This will make it easier to spot errors.

Adding New Voices

Once you have added the necessary files to eSpeak NG to support the new voice, you can then run:

$ ./mkdictlist Makefile.am

This will update the build system so that make will build the new voice in addition to building everything else, and add a <lang-code> target for building just that voice.

Praat Changes

The praat program is used to create and edit the spectral data files for espeak-ng. The changes to that program to support this are located on the espeak branch of the praat mirror.

eSpeak for Android

The android branch contains the sources for the eSpeak for Android program, based on the eyes-free port of eSpeak to Android.

Historical Versions

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 big_endian, espeak-edit, praat-mod, riskos, windows_dll and 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.

Bugs

Report bugs to the espeak-ng issues page on GitHub.

License Information

eSpeak NG Text-to-Speech is released under the GPL version 3 or later license.