W3cubDocs

/DOM

SpeechSynthesisUtterance.pitch

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 pitch property of the SpeechSynthesisUtterance interface gets and sets the pitch at which the utterance will be spoken at.

If unset, a default value of 1 will be used.

Syntax

var myPitch = speechSynthesisUtteranceInstance.pitch;
speechSynthesisUtteranceInstance.pitch = 1.5;

Value

A float representing the pitch value. It can range between 0 (lowest) and 2 (highest), with 1 being the default pitch for the current platform or voice. Some speech synthesis engines or voices may constrain the minimum and maximum rates further. If SSML is used, this value will be overridden by prosody tags in the markup.

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];
    }
  }
  utterThis.pitch = 1.5;
  synth.speak(utterThis);
  inputTxt.blur();
}

Specifications

Specification Status Comment
Web Speech API
The definition of 'pitch' 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/pitch