AudioBufferLoader.js

function AudioBufferLoader(context) {
  this.context = context;
  this.loadCount = 0;
  this.bufferList = {};
}

AudioBufferLoader.prototype.loadBuffer = function(name,url, cb) {

  if(name in this.bufferList){
    cb(this.bufferList[name]);
  }else{

    // Load buffer asynchronously
    var request = new XMLHttpRequest();
    request.open("GET", url, true);
    request.responseType = "arraybuffer";

    var that = this;

    request.onload = function() {
      // Asynchronously decode the audio file data in request.response
      that.context.decodeAudioData(
        request.response,
        function(buffer) {
          if (!buffer) {
            console.log('error decoding file data: ' + url);
            return;
          }

          that.bufferList[name] = buffer;
          
          cb(that.bufferList[name]);
        },
        function(error) {
          console.error('decodeAudioData error', error);
        });
    }//onload

    request.onerror = function() {
      console.log('BufferLoader: XHR error');
    }//onerror

    request.send();
  }  
}

usageAudioBufferLoader.js

try {
    // Fix up for prefixing
    window.AudioContext = window.AudioContext||window.webkitAudioContext;
    context = new AudioContext();

    var bufferLoader = new AudioBufferLoader( context);


    //bufferLoader.load();
 
  }
  catch(e) {
    console.log('Web Audio API is not supported in this browser');
  }
  
//load single Buffer
 audioData.bufferLoader.loadBuffer(name, url,function(buffer) {});
function createSource(buffer) {
    var source = context.createBufferSource();
    source.buffer = buffer;
    // Connect gain to destination.
    source.connect(context.destination);
    return {
      source: source,
    };
  
}


function playSound(source,buffer,loop) {
  source = createSource(buffer);
  source.source.loop = loop;
  source.playing = true;
  source.source.start ? source.source.start() : source.source.noteOn(0);

  return source;
}

//play
playSound(source,buffer,loop);