audio-test-4

audio4.js

var ctx = new AudioContext();
var osc = ctx.createOscillator();
var gain = ctx.createGain(); 
var levels = [1.0, 0.9, 0.8, 0.7, 0.6, 0.5, 0.4, 0.3, 0.2, 0.1];
var levelIdx = 0;
var timerId = setInterval(function () {
    if (levelIdx >= levels.length) {
        clearInterval(timerId);
        return;
    }
    console.log(levels[levelIdx]);
    gain.gain.value = levels[levelIdx]; // set gain
    if (levelIdx === 0) {
        osc.start(0);
        osc.stop(ctx.currentTime + levels.length * 0.5);
    }
    levelIdx++;
}, 500);
osc.connect(gain);
gain.connect(ctx.destination);