RTCDTMFToneChangeEvent.tone

The read-only property RTCDTMFToneChangeEvent.tone returns the DTMF character which has just begun to play, or an empty string (""). if all queued tones have finished playing (that is, RTCDTMFSender.toneBuffer is empty).

Syntax

 var tone = dtmfToneChangeEvent.tone;

Example

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>". 

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

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

Specifications

Specification
WebRTC 1.0: Real-Time Communication Between Browsers (WebRTC 1.0)
# dom-rtcdtmftonechangeevent-tone

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
tone
27
12
52
No
Yes
13.1
4.4
27
52
Yes
13.4
1.5

See also

© 2005–2021 MDN contributors.
Licensed under the Creative Commons Attribution-ShareAlike License v2.5 or later.
https://developer.mozilla.org/en-US/docs/Web/API/RTCDTMFToneChangeEvent/tone