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BaseAudioContext: createStereoPanner() method

files/en-us/web/api/baseaudiocontext/createstereopanner/index.md

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{{ APIRef("Web Audio API") }}

The createStereoPanner() method of the {{ domxref("BaseAudioContext") }} interface creates a {{ domxref("StereoPannerNode") }}, which can be used to apply stereo panning to an audio source. It positions an incoming audio stream in a stereo image using a low-cost panning algorithm.

[!NOTE] The {{domxref("StereoPannerNode.StereoPannerNode", "StereoPannerNode()")}} constructor is the recommended way to create a {{domxref("StereoPannerNode")}}; see Creating an AudioNode.

Syntax

js-nolint
createStereoPanner()

Parameters

None.

Return value

A {{domxref("StereoPannerNode")}}.

Examples

In our StereoPannerNode example (see source code) HTML we have a simple {{htmlelement("audio")}} element along with a slider {{HTMLElement("input")}} to increase and decrease pan value. In the JavaScript we create a {{domxref("MediaElementAudioSourceNode")}} and a {{domxref("StereoPannerNode")}}, and connect the two together using the connect() method. We then use an oninput event handler to change the value of the {{domxref("StereoPannerNode.pan")}} parameter and update the pan value display when the slider is moved.

Moving the slider left and right while the music is playing pans the music across to the left and right speakers of the output, respectively.

js
const audioCtx = new AudioContext();
const myAudio = document.querySelector("audio");

const panControl = document.querySelector(".panning-control");
const panValue = document.querySelector(".panning-value");

// Create a MediaElementAudioSourceNode
// Feed the HTMLMediaElement into it
const source = audioCtx.createMediaElementSource(myAudio);

// Create a stereo panner
const panNode = audioCtx.createStereoPanner();

// Event handler function to increase panning to the right and left
// when the slider is moved

panControl.oninput = () => {
  panNode.pan.setValueAtTime(panControl.value, audioCtx.currentTime);
  panValue.textContent = panControl.value;
};

// connect the MediaElementAudioSourceNode to the panNode
// and the panNode to the destination, so we can play the
// music and adjust the panning using the controls
source.connect(panNode);
panNode.connect(audioCtx.destination);

Specifications

{{Specifications}}

Browser compatibility

{{Compat}}

See also