audio_temp.html

<input type="file" id="file" />
<button onclick="window.fileLoad();">load</button>
<audio id="media" controls autoplay>
    <source src="">
</audio>

<script>
  window.getFileUrl = function () {
	var url = URL.createObjectURL(window.file.files[0]);

	return url;
};

window.fileLoad = function () {
  window.media.src = window.getFileUrl();
  window.media.load();
};

window.getSoundArray = function () {
  var audioCtx = new AudioContext;
  var source = audioCtx.createMediaElementSource(window.media);
  var processor = audioCtx.createScriptProcessor(1024, 1, 1);
  //view-source:http://www.oxxostudio.tw/demo/201512/web-audio-api-createmediaelementsource-demo2.html
  
  // else
  
  //http://www.oxxostudio.tw/articles/201509/web-audio-api-audioparam-gainnode.html
};
</script>