The gain property of the GainNode interface is an a-rate AudioParam representing the amount of gain to apply.

Syntax

var audioCtx = new AudioContext();
var gainNode = audioCtx.createGain();
gainNode.gain.value = 0.5;

Value

An AudioParam.

Note: Though the AudioParam returned is read-only, the value it represents is not.

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.

The below snippet wouldn't work as is — for a complete working example, 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');
var source;

if (navigator.mediaDevices.getUserMedia) {
 navigator.mediaDevices.getUserMedia (
   // constraints - only audio needed for this app
   {
     audio: true
   },

   // Success callback
   function(stream) {
     source = audioCtx.createMediaStreamSource(stream);

   },

   // Error callback
   function(err) {
     console.log('The following gUM error occured: ' + err);
   }
  );
} else {
   console.log('getUserMedia not supported on your browser!');
}

source.connect(gainNode);
gainNode.connect(audioCtx.destination);

  ...

mute.onclick = voiceMute;

function voiceMute() {
  if(mute.id == "") {
    gainNode.gain.setValueAtTime(0, audioCtx.currentTime);
    mute.id = "activated";
    mute.innerHTML = "Unmute";
  } else {
    gainNode.gain.setValueAtTime(1, audioCtx.currentTime);
    mute.id = "";
    mute.innerHTML = "Mute";
  }
}

Specifications

Specification Status Comment
Web Audio API
The definition of 'gain' in that specification.
Working Draft  

Browser compatibility

Update compatibility data on GitHub
DesktopMobile
ChromeEdgeFirefoxInternet ExplorerOperaSafariAndroid webviewChrome for AndroidEdge MobileFirefox for AndroidOpera for AndroidiOS SafariSamsung Internet
Basic supportChrome Full support 14Edge Full support 12Firefox Full support 25IE No support NoOpera Full support 15Safari Full support 6WebView Android Full support YesChrome Android Full support 18Edge Mobile Full support YesFirefox Android Full support 26Opera Android Full support 15Safari iOS ? Samsung Internet Android Full support Yes

Legend

Full support  
Full support
No support  
No support
Compatibility unknown  
Compatibility unknown

See also

Document Tags and Contributors

Contributors to this page: fscholz, erikadoyle, chrisdavidmills
Last updated by: fscholz,