BaseAudioContext: createGain() method

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.

ThecreateGain() method of theBaseAudioContextinterface creates aGainNode, which can be used to control theoverall gain (or volume) of the audio graph.

Note:TheGainNode()constructor is the recommended way to create aGainNode; seeCreating an AudioNode.

Syntax

createGain()

Parameters

None.

Return value

AGainNode which takes as input one or more audio sources and outputsaudio whose volume has been adjusted in gain (volume) to a level specified by the node'sGainNode.gaina-rateparameter.

Examples

The following example shows basic usage of anAudioContext to create aGainNode, which is then used to mute and unmute the audio when a Mutebutton is clicked by changing thegain property value.

The below snippet wouldn't work as is — for a complete working example, check out ourVoice-change-O-matic demo (view source.)

html

<div>  <button>Mute button</button></div>

const audioCtx = new AudioContext();const gainNode = audioCtx.createGain();const mute = document.querySelector(".mute");let source;if (navigator.mediaDevices.getUserMedia) {  navigator.mediaDevices.getUserMedia(    // constraints - only audio needed for this app    {      audio: true,    },    // Success callback    (stream) => {      source = audioCtx.createMediaStreamSource(stream);    },    // Error callback    (err) => {      console.error(`The following gUM error occurred: ${err}`);    },  );} else {  console.error("getUserMedia not supported on your browser!");}source.connect(gainNode);gainNode.connect(audioCtx.destination);// …mute.onclick = () => {  if (mute.id === "") {    // 0 means mute. If you still hear something, make sure you haven't    // connected your source into the output in addition to using the GainNode.    gainNode.gain.setValueAtTime(0, audioCtx.currentTime);    mute.id = "activated";    mute.textContent = "Unmute";  } else {    gainNode.gain.setValueAtTime(1, audioCtx.currentTime);    mute.id = "";    mute.textContent = "Mute";  }};