BaseAudioContext: createWaveShaper() method

The createWaveShaper() method of the BaseAudioContext interface creates a WaveShaperNode, which represents a non-linear distortion. It is used to apply distortion effects to your audio.

Note: The WaveShaperNode() constructor is the recommended way to create a WaveShaperNode; see Creating an AudioNode.

Syntax

createWaveShaper()

Parameters

None.

Return value

A WaveShaperNode.

Examples

The following example shows basic usage of an AudioContext to create a wave shaper node. For more complete applied examples/information, check out our Voice-change-O-matic demo (see app.js lines 108–193 for relevant code).

Note: Sigmoid functions are commonly used for distortion curves because of their natural properties. Their S-shape, for instance, helps create a smoother sounding result. We found the below distortion curve code on Stack Overflow. 

const audioCtx = new AudioContext();
const distortion = audioCtx.createWaveShaper();

// …

function makeDistortionCurve(amount) {
  const k = typeof amount === "number" ? amount : 50;
  const n_samples = 44100;
  const curve = new Float32Array(n_samples);
  const deg = Math.PI / 180;

  for (let i = 0; i < n_samples; i++) {
    const x = (i * 2) / n_samples - 1;
    curve[i] = ((3 + k) * x * 20 * deg) / (Math.PI + k * Math.abs(x));
  }
  return curve;
}

// …

distortion.curve = makeDistortionCurve(400);
distortion.oversample = "4x";

Specifications

Specification
Web Audio API
# dom-baseaudiocontext-createwaveshaper

Browser compatibility

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See also