The TextTrackList interface is used to represent a list of the text tracks defined by the <track> element, with each track represented by a separate textTrack object in the list.
Fired when a new text track has been removed from the media element. Also available via the onremovetrack property.
Usage notes
In addition to being able to obtain direct access to the text tracks present on a media element, TextTrackList lets you set event handlers on the addtrack and removetrack events, so that you can detect when tracks are added to or removed from the media element's stream.
Examples
Getting a video element's text track list
To get a media element's TextTrackList, use its textTracks property.
In this example, we have an app that displays information about the number of channels available. To keep it up to date, handlers for the addtrack and removetrack events are set up.