OscillatorNode: type property

Baseline Widely available

This feature is well established and works across many devices and browser versions. It’s been available across browsers since July 2015.

Thetype property of theOscillatorNode interface specifies what shape ofwaveform theoscillator will output. There are several common waveforms available, as well as anoption to specify a custom waveform shape. The shape of the waveform will affect thetone that is produced.

Value

A string specifying the shape of oscillator wave. The differentavailable values are:

sine: Asine wave. This is the default value.
square: Asquare wave with aduty cycle of 0.5; that is, the signal is "high" for half of each period.
sawtooth: Asawtooth wave.
triangle: Atriangle wave.
custom: A custom waveform. You never settype tocustom manually;instead, use thesetPeriodicWave()method to provide the data representing the waveform. Doing so automatically sets thetype tocustom.

Also seedifferent oscillator node types for a visualization of the different waveform shapes.

Exceptions

InvalidStateErrorDOMException: Thrown if the valuecustom was specified. To set a custom waveform, just callsetPeriodicWave(). Doing soautomatically sets the type for you.

Examples

The following example shows basic usage of anAudioContext to createan oscillator node. For an applied example, check out ourViolent Theremin demo (see app.js for relevant code).

// create web audio api contextconst audioCtx = new AudioContext();// create Oscillator nodeconst oscillator = audioCtx.createOscillator();oscillator.type = "square";oscillator.frequency.setValueAtTime(440, audioCtx.currentTime); // value in hertzoscillator.start();