webaudio-syntax-highlight.js

// Safari は, ベンダープレフィックスが必要
window.AudioContext = window.AudioContext || window.webkitAudioContext;

const audiocontext = new AudioContext();

// Autoplay Policy 対策
document.addEventListener('click', async () => {
  if (audiocontext.state !== 'running') {
    await audiocontext.resume();
  }

  // Create the instance of `AudioNode`
  const oscillator = audiocontext.createOscillator();
  const delay = audiocontext.createDelay(5);

  // `OscillatorNode` -> `AudioDestinationNode`
  oscillator.connect(audiocontext.destination);
  
  // `OscillatorNode` -> `DelayNode` -> `AudioDestinationNode`
  oscillator.connect(delay);
  delay.connect(audiocontext.destination);

  // `AudioParam`
  delay.delayTime.value = 5;

  // Immediate pronounce
  oscillator.start(0);

  // Stop after 1 sec
  oscillator.stop(audiocontext.currentTime + 1);
}, false);