SpeechSynthesis.onvoiceschanged

This is an experimental technology
Because this technology's specification has not stabilized, check the compatibility table for usage in various browsers. Also note that the syntax and behavior of an experimental technology is subject to change in future versions of browsers as the specification changes.

The onvoiceschanged property of the SpeechSynthesis interface represents an event handler that will run when the list of SpeechSynthesisVoice objects that would be returned by the SpeechSynthesis.getVoices() method has changed (when the voiceschanged event fires.)

This may occur when speech synthesis is being done on the server-side and the voices list is being determined asynchronously, or when client-side voices are installed/uninstalled while a speech synthesis application is running.

Syntax

speechSynthesisInstance.onvoiceschanged = function() { ... };

Examples

This could be used to populate a list of voices that the user can choose between when the event fires (see our Speak easy synthesis demo.) Note that Firefox doesn't support it at present, and will just return a list of voices when SpeechSynthesis.getVoices() is fired. With Chrome however, you have to wait for the event to fire before populating the list, hence the bottom if statement seen below.

var voices = [];

function populateVoiceList() {
  voices = synth.getVoices();

  for(i = 0; i < voices.length ; i++) {
    var option = document.createElement('option');
    option.textContent = voices[i].name + ' (' + voices[i].lang + ')';
    
    if(voices[i].default) {
      option.textContent += ' -- DEFAULT';
    }

    option.setAttribute('data-lang', voices[i].lang);
    option.setAttribute('data-name', voices[i].name);
    voiceSelect.appendChild(option);
  }
}

populateVoiceList();
if (speechSynthesis.onvoiceschanged !== undefined) {
  speechSynthesis.onvoiceschanged = populateVoiceList;
}

Specifications

Specification Status Comment
Web Speech API
The definition of 'onvoiceschanged' in that specification.
Draft  

Browser compatibility

Feature Chrome Firefox (Gecko) Internet Explorer Opera Safari (WebKit)
Basic support 33 No support No support No support No support
Feature Android Chrome Firefox Mobile (Gecko) Firefox OS IE Phone Opera Mobile Safari Mobile
Basic support (Yes) (Yes) No support No support No support No support No support

See also

Document Tags and Contributors

 Contributors to this page: tomayac, chrisdavidmills, dev.mnr.j
 Last updated by: tomayac,