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SpeechSynthesisUtterance.onstart

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 onstart property of the SpeechSynthesisUtterance interface represents an event handler that will run when the utterance has begun to be spoken (when the start event fires.)

This occurs when the SpeechSynthesis.speak() method is invoked.

Syntax

speechSynthesisUtteranceInstance.onstart = function() { ... };

Examples

var synth = window.speechSynthesis;

var inputForm = document.querySelector('form');
var inputTxt = document.querySelector('input');
var voiceSelect = document.querySelector('select');

var voices = synth.getVoices();

  ...

inputForm.onsubmit = function(event) {
  event.preventDefault();

  var utterThis = new SpeechSynthesisUtterance(inputTxt.value);
  var selectedOption = voiceSelect.selectedOptions[0].getAttribute('data-name');
  for(i = 0; i < voices.length ; i++) {
    if(voices[i].name === selectedOption) {
      utterThis.voice = voices[i];
    }
  }

  synth.speak(utterThis);

  utterThis.onstart = function(event) {
    console.log('We have started uttering this speech: ' + event.utterance.text);
  }

  inputTxt.blur();
}

Specifications

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

Browser compatibility

Feature Chrome Edge Firefox (Gecko) Internet Explorer Opera Safari (WebKit)
Basic support 33 (Yes) 49 (49) No support ? 7
Feature Android Chrome Edge Firefox Mobile (Gecko) Firefox OS IE Phone Opera Mobile Safari Mobile
Basic support (Yes) (Yes) (Yes) No support 2.0 No support No support 7.1

See also

© 2005–2017 Mozilla Developer Network and individual contributors.
Licensed under the Creative Commons Attribution-ShareAlike License v2.5 or later.
https://developer.mozilla.org/en-US/docs/Web/API/SpeechSynthesisUtterance/onstart