Audio autoplay

window.addEventListener('load', () => {
    // noinspection JSUnresolvedVariable
    let audioCtx = new (window.AudioContext || window.webkitAudioContext)();
    let xhr = new XMLHttpRequest();
    xhr.open('GET', 'audio-autoplay.wav');
    xhr.responseType = 'arraybuffer';
    xhr.addEventListener('load', () => {
     let playsound = (audioBuffer) => {
      let source = audioCtx.createBufferSource();
      source.buffer = audioBuffer;
      source.connect(audioCtx.destination);
      source.loop = false;
      source.start();

      setTimeout(function () {
       let t = document.createElement('p');
       t.appendChild(document.createTextNode((new Date()).toLocaleString() + ': Sound played'));
       document.querySelector('.output').appendChild(t);
       playsound(audioBuffer);
      }, 1000 + Math.random()*2500);
     };

     audioCtx.decodeAudioData(xhr.response).then(playsound);
    });
    xhr.send();
   });