Experimental: This is an experimental technology
Check the Browser compatibility table carefully before using this in production.

The RTCDTMFToneChangeEvent() constructor creates a new RTCDTMFToneChangeEvent.


 var event = new RTCDTMFToneChangeEvent(type, options);



A DOMString containing the name of the event. This is always "tonechange".


A dictionary of type RTCDTMFToneChangeEventInit, which may contain one or more of the following fields:


A DOMString containing a single DTMF tone character which has just begun to play, or an empty string ("") to indicate that the previous tone has stopped playing. See Tone characters for details on what characters are permitted.

Return value

A newly-created RTCDTMFToneChangeEvent, configured as specified in the provided options.

Tone characters

The digits 0-9

These characters represent the digit keys on a telephone keypad.

The letters A-D

These characters represent the "A" through "D" keys which are part of the DTMF standard but not included on most telephones. These are not interpreted as digits. Lower-case "a"-"d" automatically gets converted to upper-case.

The pound/hash sign ("#") and the asterisk ("*")

These correspond to the similarly-labeled keys which are typically on the bottom row of the telephone keypad.

The comma (",")

This character instructs the dialing process to pause for two seconds before sending the next character in the buffer.

Note: All other characters are unrecognized and will cause insertDTMF() to throw an InvalidCharacterError DOMException.


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

Browser compatibility

BCD tables only load in the browser

See also