SpeechSynthesisUtterance

Experimental: 这是一个实验中的功能
此功能某些浏览器尚在开发中,请参考浏览器兼容性表格以得到在不同浏览器中适合使用的前缀。由于该功能对应的标准文档可能被重新修订,所以在未来版本的浏览器中该功能的语法和行为可能随之改变。

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() (en-US)
Returns a new SpeechSynthesisUtterance object instance.

Properties

SpeechSynthesisUtterance also inherits properties from its parent interface, EventTarget.

SpeechSynthesisUtterance.lang (en-US)
Gets and sets the language of the utterance.
SpeechSynthesisUtterance.pitch (en-US)
Gets and sets the pitch at which the utterance will be spoken at.
SpeechSynthesisUtterance.rate (en-US)
Gets and sets the speed at which the utterance will be spoken at.
SpeechSynthesisUtterance.text (en-US)
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 (en-US)
Gets and sets the volume that the utterance will be spoken at.

Events

Listen to these events using addEventListener() or by assigning an event listener to the oneventname property of this interface.

boundary
Fired when the spoken utterance reaches a word or sentence boundary.
Also available via the onboundary property.
end
Fired when the utterance has finished being spoken.
Also available via the onend property.
error
Fired when an error occurs that prevents the utterance from being succesfully spoken.
Also available via the onerror property
mark
Fired when the spoken utterance reaches a named SSML "mark" tag.
Also available via the onmark property.
pause
Fired when the utterance is paused part way through.
Also available via the onpause property.
resume
Fired when a paused utterance is resumed.
Also available via the onresume property.
start
Fired when the utterance has begun to be spoken.
Also available via the onstart property.

Examples

In our basic Speech synthesiser demo (source), 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 (en-US) 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() (en-US) method.

var synth = window.speechSynthesis;
var voices = synth.getVoices();

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

for(var i = 0; i < voices.length; i++) {
  var option = document.createElement('option');
  option.textContent = voices[i].name + ' (' + voices[i].lang + ')';
  option.value = i;
  voiceSelect.appendChild(option);
}

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

  var utterThis = new SpeechSynthesisUtterance(inputTxt.value);
  utterThis.voice = voices[voiceSelect.value];
  synth.speak(utterThis);
  inputTxt.blur();
}

Specifications

Specification Status Comment
Web Speech API
SpeechSynthesisUtterance
Draft

Browser compatibility

BCD tables only load in the browser

See also