work.suroh.tk/js/audio.js

// audio for events
// AUDIO SETUP
const audioEngine = new (window.AudioContext || window.webkitAudioContext)()
audioEngine.suspend()
const masterGain = audioEngine.createGain()
const audioEl = document.querySelector('#audioToggle')

masterGain.gain.value = 0.9
masterGain.connect(audioEngine.destination)
// window.onload = function() {
//   // create gain
// }

const audioToggle = () => {
  audioEl.classList.toggle('active');
  if (audioEngine.state == 'suspended') {
    audioEngine.resume()
  } else {
    audioEngine.suspend()
  }
}

audioEl.addEventListener('click', audioToggle)