The volumeControlChannel property of the AudioChannelManager interface returns a DOMString that allows you to set which audio channel should have its volume changed when you press the device's hardware volume controls.


var myVolumeControlChannelValue = navigator.mozAudioChannelManager.volumeControlChannel;
navigator.mozAudioChannelManager.volumeControlChannel = 'content';


A Boolean value


In the following simple example, we use the navigator.mozAudioChannelManager property to access the app's AudioChannelManager object, first to do some rudimentary feature detection, and then to set value of the AudioChannelManager.volumeControlChannel property, based on a received variable.

var channelValue = 'content';

if (navigator.mozAudioChannelManager) {
  if(channelValue == 'normal') {
    navigator.mozAudioChannelManager.volumeControlChannel = 'normal';
  } else if(channelValue == 'content') {
    navigator.mozAudioChannelManager.volumeControlChannel = 'content';

Note: For a complete working example, see our audio-channels-demo. Try running this on your Firefox OS device as an installed app (install it using App Manager/WebIDE) and then see what happens when you play the music and then put the app in the background, with the channel set to normal, then content.


The AudioChannels API has no official spec at the moment; see for implementation details, WebIDL, etc.

Browser compatibility

Feature Chrome Firefox (Gecko) Internet Explorer Opera Safari (WebKit)
General support No support No support No support No support No support
Feature Android Chrome Firefox Mobile (Gecko) Firefox OS IE Phone Opera Mobile Safari Mobile
General support No support No support No support 1.0.1 No support No support No support

See also


© 2016 Mozilla Contributors
Licensed under the Creative Commons Attribution-ShareAlike License v2.5 or later.

API Audio audio AudioChannelManager AudioChannels Firefox OS Non-standard Property Reference volumeControlChannel