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SpeechSynthesisEvent

The SpeechSynthesisEvent interface of the Web Speech API contains information about the current state of SpeechSynthesisUtterance objects that have been processed in the speech service.

Event SpeechSynthesisEvent

Constructor

SpeechSynthesisEvent()

Creates a new SpeechSynthesisEvent.

Instance properties

The SpeechSynthesisEvent interface also inherits properties from its parent interface, Event.

SpeechSynthesisEvent.charIndex Read only

Returns the index position of the character in the SpeechSynthesisUtterance.text that was being spoken when the event was triggered.

SpeechSynthesisEvent.charLength Read only

Returns the number of characters left to be spoken after the charIndex position, if the speaking engine supports it. Returns 0 if the speaking engine can't provide the information.

SpeechSynthesisEvent.elapsedTime Read only

Returns the elapsed time in seconds after the SpeechSynthesisUtterance.text started being spoken that the event was triggered at.

SpeechSynthesisEvent.name Read only

Returns the name associated with certain types of events occurring as the SpeechSynthesisUtterance.text is being spoken: the name of the SSML marker reached in the case of a mark event, or the type of boundary reached in the case of a boundary event.

SpeechSynthesisEvent.utterance Read only

Returns the SpeechSynthesisUtterance instance that the event was triggered on.

Instance methods

The SpeechSynthesisEvent interface also inherits methods from its parent interface, Event.

Examples

utterThis.onpause = (event) => {
  const char = event.utterance.text.charAt(event.charIndex);
  console.log(
    `Speech paused at character ${event.charIndex} of "${event.utterance.text}", which is "${char}".`
  );
};

utterThis.onboundary = (event) => {
  console.log(
    `${event.name} boundary reached after ${event.elapsedTime} seconds.`
  );
};

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
SpeechSynthesisEvent 71 14 49 No 58 16 No 71 62 No 16 10.0
SpeechSynthesisEvent 33 14 49 No 21 7
NoSee bug 487255.
33 62 No 7 3.0
charIndex 33 14 49 No 21 7 No 33 62 No 7 3.0
charLength 77 15 53 No 64 preview No 77 62 No No 12.0
elapsedTime 33 14 49 No 21 7 No 33 62 No 7 3.0
name 33 14 49 No 21 7 No 33 62 No 7 3.0
utterance 33 14 49 No 21 7 No 33 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/SpeechSynthesisEvent