AudioParam: setValueCurveAtTime() 方法

setValueCurveAtTime(values, startTime, duration)

// create audio context
const audioCtx = new AudioContext();

// set basic variables for example
const myAudio = document.querySelector("audio");

const valueCurve = document.querySelector(".value-curve");

// Create a MediaElementAudioSourceNode
// Feed the HTMLMediaElement into it
const source = audioCtx.createMediaElementSource(myAudio);

// Create a gain node and set its gain value to 0.5
const gainNode = audioCtx.createGain();
gainNode.gain.value = 0.5;
const currGain = gainNode.gain.value;

// connect the AudioBufferSourceNode to the gainNode
// and the gainNode to the destination
source.connect(gainNode);
gainNode.connect(audioCtx.destination);

// set button to do something onclick

const waveArray = new Float32Array(9);
waveArray[0] = 0.5;
waveArray[1] = 1;
waveArray[2] = 0.5;
waveArray[3] = 0;
waveArray[4] = 0.5;
waveArray[5] = 1;
waveArray[6] = 0.5;
waveArray[7] = 0;
waveArray[8] = 0.5;

valueCurve.onclick = () => {
  gainNode.gain.setValueCurveAtTime(waveArray, audioCtx.currentTime, 2);
};