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The AudioListener interface represents the position and orientation of the unique person listening to the audio scene, and is used in audio spatialization. All PannerNodes spatialize in relation to the AudioListener stored in the BaseAudioContext.listener attribute.

It is important to note that there is only one listener per context and that it isn't an AudioNode.

We see the position, up and front vectors of an AudioListener, with the up and front vectors at 90° from the other.

Properties

Inherits properties from its parent, AudioNode.

The position, forward, and up value are set and retrieved using different syntaxes. Retrieval is done by accessing, for example, AudioListener.positionX, while setting the same property is done with AudioListener.positionX.value. This is why these values are not marked read only, which is how they appear in the specification's IDL.

AudioListener.positionX
Represents the horizontal position of the listener in a right-hand cartesian coordinate sytem. The default is 0.
AudioListener.positionY
Represents the vertical position of the listener in a right-hand cartesian coordinate sytem. The default is 0.
AudioListener.positionZ
Represents the longitudinal (back and forth) position of the listener in a right-hand cartesian coordinate sytem. The default is 0.
AudioListener.forwardX
Represents the horizontal position of the listener's forward direction in the same cartesian coordinate sytem as the position (positionX, positionY, and positionZ) values. The forward and up values are linearly independent of each other. The default is 0.
AudioListener.forwardY
Represents the vertical position of the listener's forward direction in the same cartesian coordinate sytem as the position (positionX, positionY, and positionZ) values. The forward and up values are linearly independent of each other. The default is 0.
AudioListener.forwardZ
Represents the longitudinal (back and forth) position of the listener's forward direction in the same cartesian coordinate sytem as the position (positionX, positionY, and positionZ) values. The forward and up values are linearly independent of each other. The default is -1.
AudioListener.upX
Represents the horizontal position of the top of the listener's head in the same cartesian coordinate sytem as the position (positionX, positionY, and positionZ) values. The forward and up values are linearly independent of each other. The default is 0.
AudioListener.upY
Represents the vertical position of the top of the listener's head in the same cartesian coordinate sytem as the position (positionX, positionY, and positionZ) values. The forward and up values are linearly independent of each other. The default is 1.
AudioListener.upZ
Represents the longitudinal (back and forth) position of the top of the listener's head in the same cartesian coordinate sytem as the position (positionX, positionY, and positionZ) values. The forward and up values are linearly independent of each other. The default is 0.

Methods

Inherits methods from its parent, AudioNode.

Deprecated features

AudioListener.dopplerFactor
A double value representing the amount of pitch shift to use when rendering a doppler effect.
AudioListener.speedOfSound
Is a double value representing the speed of sound, in meters per second.
AudioListener.setOrientation()
Sets the orientation of the listener.
AudioListener.setPosition()
Sets the position of the listener.

In a previous version of the specification, the dopplerFactor and speedOfSound properties and the setPosition() method could be used to control the doppler effect applied to AudioBufferSourceNodes connected downstream — these would be pitched up and down according to the relative speed of the PannerNode and the AudioListener. These features had a number of problems:

  • Only AudioBufferSourceNodes were pitched up or down, not other source nodes.
  • The behavior to adopt when an AudioBufferSourceNode was connected to multiple PannerNodes was unclear.
  • Because the velocity of the panner and the listener were not AudioParams, the pitch modification could not be smoothly applied, resulting in audio glitches.

Because of these issues, these properties and methods have been removed.

The setOrientation() and setPosition() methods have been replaced by setting their property value equivilents. For example setPosition(x, y, z) can be achieved by setting positionX.value, positionY.value, and positionZ.value respectively.

Example

In the following example, you can see an example of how the createPanner() method, AudioListener  and PannerNode would be used to control audio spatialisation. Generally you will define the position in 3D space that your audio listener and panner (source) occupy initially, and then update the position of one or both of these as the application is used. You might be moving a character around inside a game world for example, and wanting delivery of audio to change realistically as your character moves closer to or further away from a music player such as a stereo. In the example you can see this being controlled by the functions moveRight(), moveLeft(), etc., which set new values for the panner position via the PositionPanner() function.

To see a complete implementation, check out our panner-node example (view the source code) — this demo transports you to the 2.5D "Room of metal", where you can play a track on a boom box and then walk around the boom box to see how the sound changes!

Note how we have used some feature detection to either give the browser the newer property values (like AudioListener.forwardX) for setting position, etc. if it supports those, or older methods (like AudioListener.setOrientation()) if it still supports those but not the new properties.

// set up listener and panner position information
var WIDTH = window.innerWidth;
var HEIGHT = window.innerHeight;

var xPos = Math.floor(WIDTH/2);
var yPos = Math.floor(HEIGHT/2);
var zPos = 295;

// define other variables

var AudioContext = window.AudioContext || window.webkitAudioContext;
var audioCtx = new AudioContext();

var panner = audioCtx.createPanner();
panner.panningModel = 'HRTF';
panner.distanceModel = 'inverse';
panner.refDistance = 1;
panner.maxDistance = 10000;
panner.rolloffFactor = 1;
panner.coneInnerAngle = 360;
panner.coneOuterAngle = 0;
panner.coneOuterGain = 0;

if(panner.orientationX) {
  panner.orientationX.setValueAtTime(1, audioCtx.currentTime);
  panner.orientationY.setValueAtTime(0, audioCtx.currentTime);
  panner.orientationZ.setValueAtTime(0, audioCtx.currentTime);
} else {
  panner.setOrientation(1,0,0);
}

var listener = audioCtx.listener;

if(listener.forwardX) {
  listener.forwardX.setValueAtTime(0, audioCtx.currentTime);
  listener.forwardY.setValueAtTime(0, audioCtx.currentTime);
  listener.forwardZ.setValueAtTime(-1, audioCtx.currentTime);
  listener.upX.setValueAtTime(0, audioCtx.currentTime);
  listener.upY.setValueAtTime(1, audioCtx.currentTime);
  listener.upZ.setValueAtTime(0, audioCtx.currentTime);
} else {
  listener.setOrientation(0,0,-1,0,1,0);
}

var source;

var play = document.querySelector('.play');
var stop = document.querySelector('.stop');

var boomBox = document.querySelector('.boom-box');

var listenerData = document.querySelector('.listener-data');
var pannerData = document.querySelector('.panner-data');

leftBound = (-xPos) + 50;
rightBound = xPos - 50;

xIterator = WIDTH/150;

// listener will always be in the same place for this demo

if(listener.positionX) {
  listener.positionX.setValueAtTime(xPos, audioCtx.currentTime);
  listener.positionY.setValueAtTime(yPos, audioCtx.currentTime);
  listener.positionZ.setValueAtTime(300, audioCtx.currentTime);
} else {
  listener.setPosition(xPos,yPos,300);
}

listenerData.innerHTML = 'Listener data: X ' + xPos + ' Y ' + yPos + ' Z ' + 300;

// panner will move as the boombox graphic moves around on the screen
function positionPanner() {
  if(panner.positionX) {
    panner.positionX.setValueAtTime(xPos, audioCtx.currentTime);
    panner.positionY.setValueAtTime(yPos, audioCtx.currentTime);
    panner.positionZ.setValueAtTime(zPos, audioCtx.currentTime);
  } else {
    panner.setPosition(xPos,yPos,zPos);
  }
  pannerData.innerHTML = 'Panner data: X ' + xPos + ' Y ' + yPos + ' Z ' + zPos;
}

Note: In terms of working out what position values to apply to the listener and panner, to make the sound appropriate to what the visuals are doing on screen, there is quite a bit of math involved, but you will soon get used to it with a bit of experimentation.

Specifications

Specification Status Comment
Web Audio API
The definition of 'AudioListener' 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 support
Deprecated
Chrome Full support 14Edge Full support YesFirefox 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
dopplerFactor
Deprecated
Chrome No support 14 — 56Edge Full support 12Firefox No support 25 — 63IE No support NoOpera No support 15 — 43Safari Full support 6WebView Android No support ? — 56Chrome Android No support 18 — 56Edge Mobile Full support YesFirefox Android No support 26 — 63Opera Android No support 15 — 43Safari iOS ? Samsung Internet Android Full support Yes
forwardXChrome Full support 52Edge Full support YesFirefox No support No
Notes
No support No
Notes
Notes Supports a deprecated way of setting orientation — the setOrientation() method.
IE No support NoOpera Full support 39Safari No support NoWebView Android Full support 52Chrome Android Full support 52Edge Mobile Full support YesFirefox Android No support No
Notes
No support No
Notes
Notes Supports a deprecated way of setting orientation — the setOrientation() method.
Opera Android Full support 39Safari iOS ? Samsung Internet Android No support No
forwardYChrome Full support 52Edge Full support YesFirefox No support No
Notes
No support No
Notes
Notes Supports a deprecated way of setting orientation — the setOrientation() method.
IE No support NoOpera Full support 39Safari No support NoWebView Android Full support 52Chrome Android Full support 52Edge Mobile Full support YesFirefox Android No support No
Notes
No support No
Notes
Notes Supports a deprecated way of setting orientation — the setOrientation() method.
Opera Android Full support 39Safari iOS ? Samsung Internet Android No support No
forwardZChrome Full support 52Edge Full support YesFirefox No support No
Notes
No support No
Notes
Notes Supports a deprecated way of setting orientation — the setOrientation() method.
IE No support NoOpera Full support 39Safari No support NoWebView Android Full support 52Chrome Android Full support 52Edge Mobile Full support YesFirefox Android No support No
Notes
No support No
Notes
Notes Supports a deprecated way of setting orientation — the setOrientation() method.
Opera Android Full support 39Safari iOS ? Samsung Internet Android No support No
positionXChrome Full support 52Edge Full support YesFirefox No support No
Notes
No support No
Notes
Notes Supports a deprecated way of setting orientation — the setOrientation() method.
IE No support NoOpera Full support 39Safari No support NoWebView Android Full support 52Chrome Android Full support 52Edge Mobile Full support YesFirefox Android No support No
Notes
No support No
Notes
Notes Supports a deprecated way of setting orientation — the setOrientation() method.
Opera Android Full support 39Safari iOS ? Samsung Internet Android No support No
positionYChrome Full support 52Edge Full support YesFirefox No support No
Notes
No support No
Notes
Notes Supports a deprecated way of setting orientation — the setOrientation() method.
IE No support NoOpera Full support 39Safari No support NoWebView Android Full support 52Chrome Android Full support 52Edge Mobile Full support YesFirefox Android No support No
Notes
No support No
Notes
Notes Supports a deprecated way of setting orientation — the setOrientation() method.
Opera Android Full support 39Safari iOS ? Samsung Internet Android No support No
positionZChrome Full support 52Edge Full support YesFirefox No support No
Notes
No support No
Notes
Notes Supports a deprecated way of setting orientation — the setOrientation() method.
IE No support NoOpera Full support 39Safari No support NoWebView Android Full support 52Chrome Android Full support 52Edge Mobile Full support YesFirefox Android No support No
Notes
No support No
Notes
Notes Supports a deprecated way of setting orientation — the setOrientation() method.
Opera Android Full support 39Safari iOS ? Samsung Internet Android No support No
speedOfSound
Deprecated
Chrome No support 14 — 56Edge Full support 12Firefox No support 25 — 63IE No support NoOpera No support 15 — 43Safari Full support 6WebView Android No support ? — 56Chrome Android No support 18 — 56Edge Mobile Full support YesFirefox Android No support 26 — 63Opera Android No support 15 — 43Safari iOS ? Samsung Internet Android Full support Yes
upXChrome Full support 52Edge Full support YesFirefox No support No
Notes
No support No
Notes
Notes Supports a deprecated way of setting orientation — the setOrientation() method.
IE No support NoOpera Full support 39Safari No support NoWebView Android Full support 52Chrome Android Full support 52Edge Mobile Full support YesFirefox Android No support No
Notes
No support No
Notes
Notes Supports a deprecated way of setting orientation — the setOrientation() method.
Opera Android Full support 39Safari iOS ? Samsung Internet Android No support No
upYChrome Full support 52Edge Full support YesFirefox No support No
Notes
No support No
Notes
Notes Supports a deprecated way of setting orientation — the setOrientation() method.
IE No support NoOpera Full support 39Safari No support NoWebView Android Full support 52Chrome Android Full support 52Edge Mobile Full support YesFirefox Android No support No
Notes
No support No
Notes
Notes Supports a deprecated way of setting orientation — the setOrientation() method.
Opera Android Full support 39Safari iOS ? Samsung Internet Android No support No
upZChrome Full support 52Edge Full support YesFirefox No support No
Notes
No support No
Notes
Notes Supports a deprecated way of setting orientation — the setOrientation() method.
IE No support NoOpera Full support 39Safari No support NoWebView Android Full support 52Chrome Android Full support 52Edge Mobile Full support YesFirefox Android No support No
Notes
No support No
Notes
Notes Supports a deprecated way of setting orientation — the setOrientation() method.
Opera Android Full support 39Safari iOS ? Samsung Internet Android No support No
setOrientation
DeprecatedNon-standard
Chrome Full support 14Edge Full support 18Firefox Full support 25IE No support NoOpera Full support 15Safari Full support 6WebView Android Full support YesChrome Android Full support 18Edge Mobile No support NoFirefox Android Full support 26Opera Android Full support 15Safari iOS ? Samsung Internet Android Full support Yes
setPosition
DeprecatedNon-standard
Chrome 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 No support NoFirefox 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
Non-standard. Expect poor cross-browser support.
Non-standard. Expect poor cross-browser support.
Deprecated. Not for use in new websites.
Deprecated. Not for use in new websites.
See implementation notes.
See implementation notes.

See also

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最后编辑者: okoboji,