This is an experimental technology
Check the Browser compatibility table carefully before using this in production.
The SpeechSynthesisUtterance
interface of the Web Speech API represents a speech request. It contains the content the speech service should read and information about how to read it (e.g. language, pitch and volume.)
Constructor
SpeechSynthesisUtterance.SpeechSynthesisUtterance()
- Returns a new
SpeechSynthesisUtterance
object instance.
Properties
SpeechSynthesisUtterance
also inherits properties from its parent interface, EventTarget
.
SpeechSynthesisUtterance.lang
- Gets and sets the language of the utterance.
SpeechSynthesisUtterance.pitch
- Gets and sets the pitch at which the utterance will be spoken at.
SpeechSynthesisUtterance.rate
- Gets and sets the speed at which the utterance will be spoken at.
SpeechSynthesisUtterance.text
- Gets and sets the text that will be synthesised when the utterance is spoken.
SpeechSynthesisUtterance.voice
- Gets and sets the voice that will be used to speak the utterance.
SpeechSynthesisUtterance.volume
- Gets and sets the volume that the utterance will be spoken at.
Event handlers
SpeechSynthesisUtterance.onboundary
- Fired when the spoken utterance reaches a word or sentence boundary.
SpeechSynthesisUtterance.onend
- Fired when the utterance has finished being spoken.
SpeechSynthesisUtterance.onerror
- Fired when an error occurs that prevents the utterance from being succesfully spoken.
SpeechSynthesisUtterance.onmark
- Fired when the spoken utterance reaches a named SSML "mark" tag.
SpeechSynthesisUtterance.onpause
- Fired when the utterance is paused part way through.
SpeechSynthesisUtterance.onresume
- Fired when a paused utterance is resumed.
SpeechSynthesisUtterance.onstart
- Fired when the utterance has begun to be 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(), use the constructor
to create a new utterance 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('input'); var voiceSelect = document.querySelector('select'); 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); } 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); inputTxt.blur(); }
Specifications
Specification | Status | Comment |
---|---|---|
Web Speech API The definition of 'SpeechSynthesisUtterance' in that specification. |
Draft |
Browser compatibility
Feature | Chrome | Edge | Firefox (Gecko) | Internet Explorer | Opera | Safari (WebKit) |
---|---|---|---|---|---|---|
Basic support | 33 | (Yes) | 49 (49) | No support | (Yes) | 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 |