connect() method of the
AudioNode interface lets you connect one of the node's outputs to a target, which may be either another
AudioNode (thereby directing the sound data to the specified node) or an
AudioParam, so that the node's output data is automatically used to change the value of that parameter over time.
var destinationNode = AudioNode.connect(destination, outputIndex, inputIndex); AudioNode.connect(destination, outputIndex);
AudioParamto which to connect.
- An index specifying which output of the current
AudioNodeto connect to the destination. The index numbers are defined according to the number of output channels (see Audio channels). While you can only connect a given output to a given input once (repeated attempts are ignored), you can connect an output to multiple inputs by calling
connect()repeatedly. This makes fan-out possible. The default value is 0.
- An index describing which input of the destination you want to connect the current
AudioNodeto; the default is 0. The index numbers are defined according to the number of input channels (see Audio channels). It is possible to connect an
AudioNode, which in turn connects back to the first
AudioNode, creating a cycle. This is allowed only if there is at least one
DelayNodein the cycle. Otherwise, a
NotSupportedErrorexception is thrown. This parameter is not allowed if the destination is an
If the destination is an
- The value specified as
inputIndexdoesn't correspond to an existing input or output.
- The destination node is not part of the same audio context as the source node.
- The specified connection would create a cycle (in which the audio loops back through the same nodes repeatedly) and there are no
DelayNodes in the cycle to prevent the resulting waveform from getting stuck constructing the same audio frame indefinitely.
Connecting to an audio input
The most obvious use of the
connect() method is to direct the audio output from one node into the audio input of another node for further processing. For example, you might send the audio from a
MediaElementAudioSourceNode—that is, the audio from an HTML5 media element such as
<audio>—through a band pass filter implemented using a
BiquadFilterNode to reduce noise before then sending the audio along to the speakers.
This example creates an oscillator, then links it to a gain node, so that the gain node controls the volume of the oscillator node.
var AudioContext = window.AudioContext || window.webkitAudioContext; var audioCtx = new AudioContext(); var oscillator = audioCtx.createOscillator(); var gainNode = audioCtx.createGain(); oscillator.connect(gainNode); gainNode.connect(audioCtx.destination);
Connecting to a parameter input
You can also connect the output of a node to a single input of an
AudioParam (this is known as fan-in). This lets you easily use an audio signal to change the value of one or more parameters. A node's output can be connected to multiple
AudioParams (allowing the node's output to control the value of multiple parameters—a technique known as fan-out), and multiple nodes can output their signal to a single
AudioParam, too. Both of those scenarios are achieved through multiple calls to
connect(), one for each node output to parameter pair.
|Web Audio API
The definition of 'connect() to an AudioNode' in that specification.
|Web Audio API
The definition of 'connect() to an AudioParam' in that specification.
|Feature||Chrome||Edge||Firefox (Gecko)||Internet Explorer||Opera||Safari (WebKit)|
|Basic support||10.0webkit||(Yes)||25.0 (25.0)||No support||15.0webkit||(Yes)|
|Feature||Android||Android Webview||Edge||Firefox Mobile (Gecko)||Firefox OS (Gecko)||IE Phone||Opera Mobile||Safari Mobile||Chrome for Android|