ConvolverNode: buffer property

Baseline Widely available

This feature is well established and works across many devices and browser versions. It’s been available across browsers since April 2021.

The buffer property of the ConvolverNode interface represents a mono, stereo, or 4-channel AudioBuffer containing the (possibly multichannel) impulse response used by the ConvolverNode to create the reverb effect.

This is normally a simple recording of as-close-to-an-impulse as can be found in the space you want to model. For example, if you want to model the reverb in your bathroom, you might set up a microphone near the door to record the sound of a balloon pop or synthesized impulse from the sink. That audio recording could then be used as the buffer.

This audio buffer must have the same sample-rate as the AudioContext or an exception will be thrown. At the time when this attribute is set, the buffer and the state of the attribute will be used to configure the ConvolverNode with this impulse response having the given normalization. The initial value of this attribute is null.

Value

Examples

Assigning an audio buffer

The following example creates a convolver node and assigns it an AudioBuffer.

For more complete applied examples/information, check out our Voice-change-O-matic demo (see app.js for the code that is excerpted below).

js
const audioCtx = new AudioContext();
// ...

const convolver = audioCtx.createConvolver();
// ...

// Grab audio track via fetch() for convolver node
try {
  const response = await fetch(
    "https://mdn.github.io/voice-change-o-matic/audio/concert-crowd.ogg",
  );
  const arrayBuffer = await response.arrayBuffer();
  const decodedAudio = await audioCtx.decodeAudioData(arrayBuffer);
  convolver.buffer = decodedAudio;
} catch (error) {
  console.error(
    `Unable to fetch the audio file: ${name} Error: ${err.message}`,
  );
}

Specifications

Specification
Web Audio API
# dom-convolvernode-buffer

Browser compatibility

BCD tables only load in the browser

See also