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 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.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 | Edge | Firefox (Gecko) | Internet Explorer | Opera | Safari (WebKit) |
|---|---|---|---|---|---|---|
| Basic support | 14 webkit | (Yes) | 23 [1] | No support | 15 webkit 22 (unprefixed) |
6 webkit |
| Feature | Android | Chrome | Edge | Firefox Mobile (Gecko) | Firefox OS | IE Phone | Opera Mobile | Safari Mobile |
|---|---|---|---|---|---|---|---|---|
| Basic support | No support | 28 webkit | (Yes) | 25 [1] | 1.2 | No support | No support | 6 webkit |
[1] The parameter wasn't optional until Firefox 30.