The OscillatorNode
interface represents a periodic waveform, such as a sine wave. It is an AudioScheduledSourceNode
audio-processing module that causes a specified frequency of a given wave to be created—in effect, a constant tone.
An OscillatorNode
is created using the BaseAudioContext.createOscillator()
method. It always has exactly one output and no inputs. Its basic property defaults (see AudioNode
for definitions) are:
Number of inputs | 0 |
---|---|
Number of outputs | 1 |
Channel count mode | max |
Channel count | 2 (not used in the default count mode) |
Channel interpretation | speakers |
Constructor
OscillatorNode()
- Creates a new instance of an
OscillatorNode
object, optionally providing an object specifying default values for the node's properties. If the default values are acceptable, you can simply call theBaseAudioContext.createOscillator()
factory method.
Properties
Inherits properties from its parent, AudioScheduledSourceNode
, and adds the following properties:
OscillatorNode.frequency
- An a-rate
AudioParam
representing the frequency of oscillation in hertz (though theAudioParam
returned is read-only, the value it represents is not). The default value is 440 Hz (a standard middle-A note).
OscillatorNode.detune
- An a-rate
AudioParam
representing detuning of oscillation in cents (though theAudioParam
returned is read-only, the value it represents is not). The default value is 0.
OscillatorNode.type
- A string which specifies the shape of waveform to play; this can be one of a number of standard values, or
custom
to use aPeriodicWave
to describe a custom waveform. Different waves will produce different tones. Standard values are"sine"
,"square"
,"sawtooth"
,"triangle"
and"custom"
. The default is"sine"
.
Event handlers
OscillatorNode.onended
- Sets the event handler for the
ended
event, which fires when the tone has stopped playing.
Methods
Inherits methods from its parent, AudioScheduledSourceNode
, and adds the following:
OscillatorNode.setPeriodicWave()
- Sets a
PeriodicWave
which describes a periodic waveform to be used instead of one of the standard waveforms; calling this sets thetype
tocustom
. This replaces the now-obsoleteOscillatorNode.setWaveTable()
method. OscillatorNode.start()
- Specifies the exact time to start playing the tone.
OscillatorNode.stop()
- Specifies the time to stop playing the tone.
Examples
The following example shows basic usage of an AudioContext
to create an oscillator node and to start playing a tone on it. For an applied example, check out our Violent Theremin demo (see app.js for relevant code).
// create web audio api context var audioCtx = new (window.AudioContext || window.webkitAudioContext)(); // create Oscillator node var oscillator = audioCtx.createOscillator(); oscillator.type = 'square'; oscillator.frequency.setValueAtTime(440, audioCtx.currentTime); // value in hertz oscillator.connect(audioCtx.destination); oscillator.start();
Specifications
Specification | Status | Comment |
---|---|---|
Web Audio API The definition of 'OscillatorNode' in that specification. |
Working Draft |
Browser compatibility
Desktop | Mobile | |||||||||||
---|---|---|---|---|---|---|---|---|---|---|---|---|
OscillatorNode | Chrome Full support 14 | Edge Full support ≤18 | Firefox Full support 25 | IE No support No | Opera Full support 15 | Safari Full support 6 | WebView Android Full support Yes | Chrome Android Full support 18 | Firefox Android Full support 26 | Opera Android Full support 14 | Safari iOS Full support Yes | Samsung Internet Android Full support 1.0 |
OscillatorNode() constructor | Chrome
Full support
55
| Edge Full support ≤79 | Firefox Full support 53 | IE No support No | Opera Full support 42 | Safari ? | WebView Android
Full support
55
| Chrome Android
Full support
55
| Firefox Android Full support 53 | Opera Android Full support 42 | Safari iOS ? | Samsung Internet Android
Full support
6.0
|
detune | Chrome Full support 14 | Edge Full support 12 | Firefox Full support 25 | IE No support No | Opera Full support 15 | Safari Full support 6 | WebView Android Full support Yes | Chrome Android Full support 18 | Firefox Android Full support 26 | Opera Android Full support 14 | Safari iOS Full support Yes | Samsung Internet Android Full support 1.0 |
frequency | Chrome Full support 14 | Edge Full support 12 | Firefox Full support 25 | IE No support No | Opera Full support 15 | Safari Full support 6 | WebView Android Full support Yes | Chrome Android Full support 18 | Firefox Android Full support 26 | Opera Android Full support 14 | Safari iOS Full support Yes | Samsung Internet Android Full support 1.0 |
onended | Chrome Full support 14 | Edge Full support 12 | Firefox Full support 25 | IE No support No | Opera Full support 15 | Safari Full support 6 | WebView Android Full support Yes | Chrome Android Full support 18 | Firefox Android Full support 26 | Opera Android Full support 14 | Safari iOS ? | Samsung Internet Android Full support 1.0 |
setPeriodicWave | Chrome Full support 14 | Edge Full support 12 | Firefox Full support 25 | IE No support No | Opera Full support 15 | Safari Full support 6 | WebView Android Full support Yes | Chrome Android Full support 18 | Firefox Android Full support 26 | Opera Android Full support 14 | Safari iOS Full support Yes | Samsung Internet Android Full support 1.0 |
start | Chrome Full support 14 | Edge Full support 12 | Firefox
Full support
25
| IE No support No | Opera Full support 15 | Safari Full support 6 | WebView Android Full support Yes | Chrome Android Full support 18 | Firefox Android
Full support
26
| Opera Android Full support 14 | Safari iOS ? | Samsung Internet Android Full support 1.0 |
stop | Chrome Full support 14 | Edge Full support 12 | Firefox
Full support
25
| IE No support No | Opera Full support 15 | Safari Full support 6 | WebView Android Full support Yes | Chrome Android Full support 18 | Firefox Android
Full support
26
| Opera Android Full support 14 | Safari iOS ? | Samsung Internet Android Full support 1.0 |
type | Chrome Full support 14 | Edge Full support 12 | Firefox Full support 25 | IE No support No | Opera Full support 15 | Safari Full support 6 | WebView Android Full support Yes | Chrome Android Full support 18 | Firefox Android Full support 26 | Opera Android Full support 14 | Safari iOS Full support Yes | Samsung Internet Android Full support 1.0 |
Legend
- Full support
- Full support
- No support
- No support
- Compatibility unknown
- Compatibility unknown
- See implementation notes.
- See implementation notes.