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AudioContext.createConvolver()

The createConvolver() method of the AudioContext interface creates a ConvolverNode, which is commonly used to apply reverb effects to your audio. See the spec definition of Convolution for more information.

Syntax

var audioCtx = new AudioContext();
var convolver = audioCtx.createConvolver();

Returns

A ConvolverNode.

Example

The following example shows basic usage of an AudioContext to create a convolver node. The basic premise is that you create an AudioBuffer containing a sound sample to be used as an ambience to shape the convolution (called the impulse response,) and apply that to the convolver. The example below uses a short sample of a concert hall crowd, so the reverb effect applied is really deep and echoey.

For applied examples/information, check out our Voice-change-O-matic demo (see app.js for relevant code).

var audioCtx = new (window.AudioContext || window.webkitAudioContext)();
var convolver = audioCtx.createConvolver();

  ...

// grab audio track via XHR for convolver node

var soundSource, concertHallBuffer;

ajaxRequest = new XMLHttpRequest();
ajaxRequest.open('GET', 'concert-crowd.ogg', true);
ajaxRequest.responseType = 'arraybuffer';

ajaxRequest.onload = function() {
  var audioData = ajaxRequest.response;
  audioCtx.decodeAudioData(audioData, function(buffer) {
      concertHallBuffer = buffer;
      soundSource = audioCtx.createBufferSource();
      soundSource.buffer = concertHallBuffer;
    }, function(e){"Error with decoding audio data" + e.err});
}

ajaxRequest.send();

  ...

convolver.buffer = concertHallBuffer;

Specifications

Specification Status Comment
Web Audio API
The definition of 'createConvolver()' 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)
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: teoli, chrisdavidmills
 Last updated by: teoli,