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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 Optional
An optional double representing the time when the oscillator should start. If a value is not included or is in the past, the oscillator 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.setValueAtTime(3000, audioCtx.currentTime); // 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 Edge Firefox Internet Explorer Opera Safari
Basic support 14 Yes 251 No 15 6
Feature Android webview Chrome for Android Edge mobile Firefox for Android IE mobile Opera Android iOS Safari
Basic support Yes 14 Yes 261 No 15 ?

1. Before Firefox 30, the when parameter was not optional.

See also

© 2005–2018 Mozilla Developer Network and individual contributors.
Licensed under the Creative Commons Attribution-ShareAlike License v2.5 or later.
https://developer.mozilla.org/en-US/docs/Web/API/OscillatorNode/start