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    GainNode

    The GainNode interface represents a change in volume. It is an AudioNode audio-processing module that causes a given gain to be applied to the input data before its propagation to the output. A GainNode always has exactly one input and one output, both with the same number of channels.

    The gain is a unitless value, changing with time, that is multiplied to each corresponding sample of all input channels. If modified, the new gain is applied using a de-zippering algorithm in order to prevent unaesthetic 'clicks' from appearing in the resulting audio.

    The GainNode is increasing the gain of the output.

    • Number of inputs 1
    • Number of outputs 1
    • Channel count mode "max"
    • Channel count 2 (not used in the default count mode)
    • Channel interpretation "speakers"

    Properties

    Inherits properties from its parent, AudioNode.

    GainNode.gain Read only
    Is an a-rate AudioParam representing the amount of gain to apply.

    Methods

    No specific method; inherits methods from its parent, AudioNode.

    Example

    The following example shows basic usage of an AudioContext to create a GainNode, which is then used to mute and unmute the audio when a Mute button is clicked by changing the gain property value. For more complete applied examples/information, check out our Voice-change-O-matic demo (view source.)

    <div>
      <a class="mute">Mute button</a>
    </div>
    var audioCtx = new (window.AudioContext || window.webkitAudioContext)();
    var gainNode = audioCtx.createGain();
    var mute = document.querySelector('.mute');
    
    source.connect(gainNode);
    gainNode.connect(audioCtx.destination);
    
      ...
    
    mute.onclick = voiceMute;
    
    function voiceMute() {
      if(mute.id == "") {
        gainNode.gain.value = 0;
        mute.id = "activated";
        mute.innerHTML = "Unmute";
      } else {
        gainNode.gain.value = 1;
        mute.id = "";
        mute.innerHTML = "Mute";
      }
    }

    Specifications

    Specification Status Comment
    Web Audio API
    The definition of 'GainNode' 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
    6.0webkit
    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: Sheppy, fscholz, stuajc, Jeremie, chrisdavidmills, kscarfone, teoli
    Last updated by: Jeremie,