SpeechSynthesis: voiceschanged event

The voiceschanged event of the Web Speech API is fired when the list of SpeechSynthesisVoice objects that would be returned by the SpeechSynthesis.getVoices() method has changed (when the voiceschanged event fires.)

This could be used to repopulate a list of voices that the user can choose between when the event fires. You can use the voiceschanged event in an addEventListener method:

var synth = window.speechSynthesis;

synth.addEventListener('voiceschanged', function() {
  var voices = synth.getVoices();
  for(i = 0; i < voices.length ; i++) {
    var option = document.createElement('option');
    option.textContent = voices[i].name + ' (' + voices[i].lang + ')';
    option.setAttribute('data-lang', voices[i].lang);
    option.setAttribute('data-name', voices[i].name);
    voiceSelect.appendChild(option);
  }
});

Or use the onvoiceschanged event handler property:

synth.onvoiceschanged = function() {
  var voices = synth.getVoices();
  for(i = 0; i < voices.length ; i++) {
    var option = document.createElement('option');
    option.textContent = voices[i].name + ' (' + voices[i].lang + ')';
    option.setAttribute('data-lang', voices[i].lang);
    option.setAttribute('data-name', voices[i].name);
    voiceSelect.appendChild(option);
  }
}

• Web Speech API