code: function loadSample(url, doAfterLoading) {
      var fetchSound = new XMLHttpRequest(); // Load the Sound with XMLHttpRequest
      fetchSound.open("GET", url, true); // Path to Audio File
      fetchSound.responseType = "arraybuffer"; // Read as Binary Data
      fetchSound.onload = function() {
          context.decodeAudioData(fetchSound.response, doAfterLoading);
      }
      fetchSound.send();
  }
docs: function to load samples