The AudioParamDescriptor dictionary of the Web Audio API specifies properties for an AudioParam objects. It is used to create custom AudioParams on an AudioWorkletNode. If the underlying AudioWorkletProcessor has a parameterDescriptors static getter, then the returned array of objects based on this dictionary is used internally by AudioWorkletNode constructor to populate its parameters property accordingly.



The DOMString 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 可选

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

minValue 可选

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

maxValue 可选

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

defaultValue 可选

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


下面的代码片段展示了自定义的 AudioWorkletProcessor 中的静态方法 parameterDescriptors 返回该类型的描述符(这是 AudioWorkletNode.parameters 中完整示例的一部分)。

// white-noise-processor.js
class WhiteNoiseProcessor extends AudioWorkletProcessor {
  static get parameterDescriptors() {
    return [
        name: "customGain",
        defaultValue: 1,
        minValue: 0,
        maxValue: 1,
        automationRate: "a-rate",

  // …


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