The createChannelSplitter() method of the AudioContext Interface is used to create a ChannelSplitterNode, which is used to access the individual channels of an audio stream and process them separately.


var audioCtx = new AudioContext();
var splitter = audioCtx.createChannelSplitter(2);


The number of channels in the input audio stream that you want to output separately; the default is 6 if this parameter is not specified.


A ChannelSplitterNode.


The following simple example shows how you could separate a stereo track (say, a piece of music), and process the left and right channel differently. To use them, you need to use the second and third parameters of the AudioNode.connect(AudioNode) method, which allow you to specify the index of the channel to connect from and the index of the channel to connect to.

var ac = new AudioContext();
ac.decodeAudioData(someStereoBuffer, function(data) {
 var source = ac.createBufferSource();
 source.buffer = data;
 var splitter = ac.createChannelSplitter(2);
 var merger = ac.createChannelMerger(2);

 // Reduce the volume of the left channel only
 var gainNode = ac.createGain();
 gainNode.gain.value = 0.5;
 splitter.connect(gainNode, 0);

 // Connect the splitter back to the second input of the merger: we
 // effectively swap the channels, here, reversing the stereo image.
 gainNode.connect(merger, 0, 1);
 splitter.connect(merger, 1, 0);

 var dest = ac.createMediaStreamDestination();

 // Because we have used a ChannelMergerNode, we now have a stereo
 // MediaStream we can use to pipe the Web Audio graph to WebRTC,
 // MediaRecorder, etc.


Specification Status Comment
Web Audio API
The definition of 'createChannelSplitter()' in that specification.
Working Draft  

Browser compatibility

Feature Chrome Firefox (Gecko) Internet Explorer Opera Safari (WebKit)
Basic support 10.0webkit 25.0 (25.0)  No support 15.0webkit
22 (unprefixed)
Feature Android Firefox Mobile (Gecko) Firefox OS IE Mobile Opera Mobile Safari Mobile Chrome for Android
Basic support ? 26.0 1.2 ? ? ? 33.0

See also

Document Tags and Contributors

 Contributors to this page: amireldor, klesun, teoli, chrisdavidmills
 Last updated by: amireldor,