gistfile1.txt

var audioCtx = new (window.AudioContext || window.webkitAudioContext)();
var duration = 0;
var silence = 0;
var processor = audioCtx.createScriptProcessor(0, 1, 1);
processor.onaudioprocess = function(evt){
    duration += evt.inputBuffer.duration;
    var input = evt.inputBuffer.getChannelData(0)
      , len = input.length
      , total = i = 0
      , rms;
    while ( i < len ) total += Math.abs( input[i++] );
    rms = Math.sqrt( total / len ) * 100;
    if (rms < 15) {
        silence += evt.inputBuffer.duration;
    };
    if (silence > 2) { console.log(duration, silence, rms); silence =0}
    if (duration > 10) {soundSource.stop();}
};

var analyser = audioCtx.createAnalyser();



var soundSource, concertHallBuffer;
ajaxRequest = new XMLHttpRequest();
ajaxRequest.open('GET', 'http://ia802309.us.archive.org/32/items/fabulas_esopo_01_librivox/fabula_01_001_esopo.mp3', true);
ajaxRequest.responseType = 'arraybuffer';
ajaxRequest.onload = function() {
var audioData = ajaxRequest.response;
audioCtx.decodeAudioData(audioData, function(buffer) {
concertHallBuffer = buffer;
soundSource = audioCtx.createBufferSource();
soundSource.buffer = concertHallBuffer;
soundSource.connect(analyser);
console.log(soundSource.buffer);
soundSource.connect(analyser);
analyser.connect(processor);

}, function(e){"Error with decoding audio data" + e.err});

soundSource.start();
}
ajaxRequest.send();