The MediaStreamAudioSourceNode interface's read-only mediaStream property indicates the MediaStream that contains the audio track from which the node is receiving audio. This stream was specified when the node was first created, either using the MediaStreamAudioSourceNode() constructor or the AudioContext.createMediaStreamSource() method.


audioSourceStream = mediaStreamAudioSourceNode.mediaStream;


A MediaStream representing the stream which contains the MediaStreamTrack serving as the source of audio for the node.

The user agent uses the first audio track it finds on the specified stream as the audio source for this node. However, there is no way to be certain which track that will be on multi-track streams. If the specific track matters to you, or you need to have access to the track itself, you should use a MediaStreamTrackAudioSourceNode instead.


const audioCtx = new window.AudioContext();
let options = {
  mediaStream : stream

let source = new MediaStreamAudioSourceNode(audioCtx, options);


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

Browser compatibility

Update compatibility data on GitHub
ChromeEdgeFirefoxInternet ExplorerOperaSafariAndroid webviewChrome for AndroidFirefox for AndroidOpera for AndroidSafari on iOSSamsung Internet
mediaStreamChrome Full support 23Edge Full support ≤79Firefox Full support 70IE No support NoOpera Full support YesSafari Full support YesWebView Android Full support YesChrome Android Full support YesFirefox Android No support NoOpera Android Full support YesSafari iOS Full support YesSamsung Internet Android Full support Yes


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