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    The createChannelMerger() method of the AudioContext Interface is used to create a ChannelMergerNode, which is used to combine channels from multiple audio streams into a single audio stream.


    var audioCtx = new AudioContext();
    var merger = audioCtx.createChannelMerger(2);


    The number of channels in the input audio streams, which the output stream will contain; the default is 6 is this parameter is not specified.


    A ChannelMergerNode.


    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 gain = ac.createGain();
     gain.value = 0.5;
     splitter.connect(gain, 0);
     // Connect the splitter back to the second input of the merger: we
     // effectively swap the channels, here, reversing the stereo image.
     gain.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 'createChannelMerger()' in that specification.
    Working Draft  

    Browser compatibility

    Feature Chrome Firefox (Gecko) Internet Explorer Opera Safari (WebKit)
    Basic support 10.0webkit 25.0 (25.0)  Not supported 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: anirudh_venkatesh, teoli, chrisdavidmills
    Last updated by: teoli,