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speak.js

A port of the eSpeak speech synthesizer from C++ to JavaScript using Emscripten.

Enables text-to-speech on the web using only JavaScript and HTML5.

Online demo: http://syntensity.com/static/espeak.html

Usage

Very simple! Do this:

  • Include the script in your html header,

    <script src="speak.js"></script>

    (and make sure you have speak.js where it will be found)

  • Add a div with an audio element called 'audio' in your html body,

    <div id="audio"></div>

  • Call speak() to say stuff in JavaScript

    speak('hello world!')

See helloworld.html for a simple 'hello world', and demo.html for a more detailed example.

Options

You can also specify some options with calling speak(), by doing

  `speak('hello world', { option1: value1, option2: value2 .. })`

available options are:

  • amplitude: How loud the voice will be (default: 100)
  • pitch: The voice pitch (default: 50)
  • speed: The speed at which to talk (words per minute) (default: 175)
  • voice: Which voice to use (for a non-default voice, requires you to build speak.js to include the proper data. See Language Support below) (default: en/en-us)
  • wordgap: Additional gap between words in 10 ms units (default: 0)

For example

  `speak('hello world', { pitch: 100 })`

will talk in a very high-pitched voice.

Building

A prebuilt version is already included, in the file speak.js. But if you want to tinker with the source code though, you might want to build it yourself. To do so, run emscripten.sh inside src/. Note that you need to change the paths there.

Language Support

eSpeak supports multiple languages so speak.js can too. To do this, you need to build a custom version of speak.js:

  • Bundle the proper language files. For french, you need fr_dict and voices/fr. See commented-out code in emscripten.sh and bundle.py
  • Expose those files to the emulated filesystem, in post.js. See commented-out code in there as well.
  • Run emscripten.sh to build.

You then need to call speak() with the voice option that tells it to use the right voice for your language. For example, for French this should work:

  `speak('boulanger', { voice: 'fr' })`