The read-only parameterDescriptors property of an AudioWorkletProcessor-derived class is a static getter, which returns an iterable of AudioParamDescriptor-based objects.

The property is not a part of the AudioWorkletProcessor interface, but, if defined, it is called internally by the AudioWorkletProcessor constructor to create a list of custom AudioParam objects in the parameters property of the associated AudioWorkletNode.

Defining the getter is optional.

An iterable of AudioParamDescriptor-based objects. The properties of these objects are as follows:

name

The string which represents the name of the AudioParam. Under this name the AudioParam will be available in the parameters property of the node, and under this name the AudioWorkletProcessor.process method will acquire the calculated values of this AudioParam.

automationRate Optional

Either "a-rate", or "k-rate" string which represents an automation rate of this AudioParam. Defaults to "a-rate".

minValue Optional

A float which represents minimum value of the AudioParam. Defaults to -3.4028235e38.

maxValue Optional

A float which represents maximum value of the AudioParam. Defaults to 3.4028235e38.

defaultValue Optional

A float which represents initial value of the AudioParam. Defaults to 0.

See AudioWorkletNode.parameters for example code showing how to add static parameterDescriptors getter to a custom AudioWorkletProcessor.

• Web Audio API
• Using the Web Audio API