Web/API/RTCDTMFSender/tonechange event

The tonechange event is sent to an RTCDTMFSender by the WebRTC API to indicate when DTMF tones previously queued for sending (by calling RTCDTMFSender.insertDTMF()) begin and end.

Bubbles	No
Cancelable	No
Interface	`RTCDTMFToneChangeEvent`
Event handler property	`ontonechange`

To determine what tone started playing, or if a tone stopped playing, check the value of the event's tone property.

Examples

This example establishes a handler for the tonechange event which updates an element to display the currently playing tone in its content, or, if all tones have played, the string "<none>".

This can be done using addEventListener():

dtmfSender.addEventListener("tonechange", ev => {
  let tone = ev.tone;
  if (tone === "") {
    tone = "&lt;none&gt;";
  }

  document.getElementById("playingTone").innerText = tone;
}, false);

You can also just set the ontonechange event handler property directly:

dtmfSender.ontonechange = function( ev ) {
  let tone = ev.tone;
  if (tone === "") {
    tone = "&lt;none&gt;"
  }

  document.getElementById("playingTone").innerText = tone;
};

Specifications

Specification	Status	Comment
WebRTC 1.0: Real-time Communication Between BrowsersThe definition of 'tonechange' in that specification.	Candidate Recommendation	Definition for the WebRTC API

Browser compatibility

Update compatibility data on GitHub

	Desktop						Mobile
	Chrome	Edge	Firefox	Internet Explorer	Opera	Safari	Android webview	Chrome for Android	Firefox for Android	Opera for Android	Safari on iOS	Samsung Internet
`tonechange` event	Chrome Full support 27	Edge Full support ≤79	Firefox Full support 52	IE No support No	Opera Full support Yes	Safari ?	WebView Android Full support Yes	Chrome Android Full support 27	Firefox Android Full support 52	Opera Android Full support Yes	Safari iOS ?	Samsung Internet Android Full support 1.5

Legend

Full support: Full support
No support: No support
Compatibility unknown: Compatibility unknown

RTCDTMFSender: tonechange event by Mozilla Contributors is licensed under CC-BY-SA 2.5.