SpeechSynthesisUtterance: boundary event
The boundary event of the Web Speech API is fired when the spoken utterance reaches a word or sentence boundary.
Syntax
Use the event name in methods like addEventListener(), or set an event handler property.
js
addEventListener("boundary", (event) => {});
onboundary = (event) => {};
Event type
A SpeechSynthesisEvent. Inherits from Event.
Event properties
In addition to the properties listed below, properties from the parent interface, Event, are available.
charIndexRead only-
Returns the index position of the character in the
SpeechSynthesisUtterance.textthat was being spoken when the event was triggered. elapsedTimeRead only-
Returns the elapsed time in seconds after the
SpeechSynthesisUtterance.textstarted being spoken that the event was triggered at. nameRead only-
Returns the name associated with certain types of events occurring as the
SpeechSynthesisUtterance.textis being spoken: the name of the SSML marker reached in the case of amarkevent, or the type of boundary reached in the case of aboundaryevent. utteranceRead only-
Returns the
SpeechSynthesisUtteranceinstance that the event was triggered on.
Examples
You can use the boundary event in an addEventListener method:
js
utterThis.addEventListener("boundary", (event) => {
console.log(
`${event.name} boundary reached after ${event.elapsedTime} seconds.`
);
});
Or use the onboundary event handler property:
js
utterThis.onboundary = (event) => {
console.log(
`${event.name} boundary reached after ${event.elapsedTime} seconds.`
);
};
Specifications
| Specification |
|---|
| Web Speech API # eventdef-speechsynthesisutterance-boundary |
| Web Speech API # dom-speechsynthesisutterance-onboundary |
Browser compatibility
BCD tables only load in the browser