SpeechSynthesisEvent: SpeechSynthesisEvent() constructor

Baseline Widely available

This feature is well established and works across many devices and browser versions. It’s been available across browsers since ⁨September 2022⁩.

The SpeechSynthesisEvent() constructor creates a new SpeechSynthesisEvent object.

Note: A web developer doesn't typically need to call this constructor, as the browser creates these objects itself when firing events.

Syntax

new SpeechSynthesisEvent(type, options)

A string with the name of the event. It is case-sensitive and browsers set it to start, end, error, pause, resume, mark, or boundary.

An object that, in addition to the properties defined in Event(), has the following properties:

utterance: A SpeechSynthesisUtterance object, which is the speech request the event was triggered on.
charIndex Optional: The index position of the character in SpeechSynthesisUtterance.text that was being spoken when the event was triggered. Its default value is 0.
charLength Optional: The number of characters left to be spoken after the character at the charIndex position. Its default value is 0.
elapsedTime Optional: The elapsed time in seconds, after the SpeechSynthesisUtterance.text started being spoken, at which the event was triggered. Its default value is 0.
name Optional: The name associated with certain types of events: 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. It defaults to the empty string ("").