SpeechSynthesisUtterance.onboundary

Experimental: This is an experimental technology
Check the Browser compatibility table carefully before using this in production.

The onboundary property of the SpeechSynthesisUtterance interface represents an event handler that will run when the spoken utterance reaches a word or sentence boundary (when the boundary event fires.)

Syntax

speechSynthesisUtteranceInstance.onboundary = 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.onboundary = function(event) {
    console.log(event.name + ' boundary reached after ' + event.elapsedTime + ' seconds.');
  }

  inputTxt.blur();
}

Specifications

Browser compatibility

Desktop Mobile
Chrome Edge Firefox Internet Explorer Opera Safari WebView Android Chrome Android Firefox for Android Opera Android Safari on IOS Samsung Internet
onboundary
33
14
49
No
21
7
No
33
The boundary event does not fire as expected. See bug 1122143.
62
No
7
3.0

See also

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Licensed under the Creative Commons Attribution-ShareAlike License v2.5 or later.
https://developer.mozilla.org/en-US/docs/Web/API/SpeechSynthesisUtterance/onboundary