SpeechSynthesis
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 SpeechSynthesis
interface of the Web Speech API is the controller interface for the speech service; this can be used to retrieve information about the synthesis voices available on the device, start and pause speech, and other commands besides.
Properties
SpeechSynthesis
also inherits properties from its parent interface, EventTarget
.
SpeechSynthesis.paused
Read only- A
Boolean
that returnstrue
if theSpeechSynthesis
object is in a paused state. SpeechSynthesis.pending
Read only- A
Boolean
that returnstrue
if the utterance queue contains as-yet-unspoken utterances. SpeechSynthesis.speaking
Read only- A
Boolean
that returnstrue
if an utterance is currently in the process of being spoken — even ifSpeechSynthesis
is in a paused state.
Event handlers
SpeechSynthesis.onvoiceschanged
- Fired when the list of
SpeechSynthesisVoice
objects that would be returned by theSpeechSynthesis.getVoices()
method has changed.
Methods
SpeechSynthesis
also inherits methods from its parent interface, EventTarget
.
SpeechSynthesis.cancel()
- Removes all utterances from the utterance queue.
SpeechSynthesis.getVoices()
- Returns a list of
SpeechSynthesisVoice
objects representing all the available voices on the current device. SpeechSynthesis.pause()
- Puts the
SpeechSynthesis
object into a paused state. SpeechSynthesis.resume()
- Puts the
SpeechSynthesis
object into a non-paused state: resumes it if it was already paused. SpeechSynthesis.speak()
- Adds an
utterance
to the utterance queue; it will be spoken when any other utterances queued before it have been spoken.
Examples
In our basic Speech synthesiser demo, we first grab a reference to the SpeechSynthesis controller using window.speechSynthesis
. After defining some necessary variables, we retrieve a list of the voices available using SpeechSynthesis.getVoices()
and populate a select menu with them so the user can choose what voice they want.
Inside the inputForm.onsubmit
handler, we stop the form submitting with preventDefault(), create a new SpeechSynthesisUtterance
instance containing the text from the text <input>
, set the utterance's voice to the voice selected in the <select>
element, and start the utterance speaking via the SpeechSynthesis.speak()
method.
var synth = window.speechSynthesis; var inputForm = document.querySelector('form'); var inputTxt = document.querySelector('.txt'); var voiceSelect = document.querySelector('select'); var pitch = document.querySelector('#pitch'); var pitchValue = document.querySelector('.pitch-value'); var rate = document.querySelector('#rate'); var rateValue = document.querySelector('.rate-value'); 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; } 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 = pitch.value; utterThis.rate = rate.value; synth.speak(utterThis); inputTxt.blur(); }
Specifications
Specification | Status | Comment |
---|---|---|
Web Speech API The definition of 'SpeechSynthesis' in that specification. |
Draft |
Browser compatibility
Feature | Chrome | Edge | Firefox (Gecko) | Internet Explorer | Opera | Safari (WebKit) |
---|---|---|---|---|---|---|
Basic support | 33 | 14.14393 | 49 (49) | No support | ? | 7 |
Feature | Android | Chrome | Firefox Mobile (Gecko) | Firefox OS | IE Phone | Opera Mobile | Safari Mobile |
---|---|---|---|---|---|---|---|
Basic support | (Yes) | (Yes) | No support | 2.0 | No support | No support | 7.1 |
See also
License
© 2016 Mozilla Contributors
Licensed under the Creative Commons Attribution-ShareAlike License v2.5 or later.
https://developer.mozilla.org/en-us/docs/web/api/speechsynthesis