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OscillatorNode.start()

The start method of the OscillatorNode interface specifies the exact time to start playing the tone. Its parameter is optional and default to 0.

Syntax

oscillator.start(when); // start playing oscillator in when seconds

Parameters

when
An optional double representing the time in seconds after the current time when the oscillator should start. If a value is not included, it defaults to 0, meaning that it starts playing immediately.

Example

The following example shows basic usage of an AudioContext to create an oscillator node. 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.value = 3000; // value in hertz
oscillator.start();

Specifications

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

Browser compatibility

Feature Chrome Firefox (Gecko) Internet Explorer Opera Safari (WebKit)
Basic support 14 webkit 23 [1] Not supported 15 webkit
22 (unprefixed)
6 webkit
Feature Android Chrome Firefox Mobile (Gecko) Firefox OS IE Phone Opera Mobile Safari Mobile
Basic support Not supported 28 webkit 25 [1] 1.2 Not supported Not supported webkit

[1] The parameter wasn't optional until Firefox 30.

See also

Document Tags and Contributors

 Contributors to this page: fscholz, teoli, chrisdavidmills
 Last updated by: fscholz,