Need use localhost, don't use file:///

microphone.js

	// success callback when requesting audio input stream
function gotStream(stream) {
    window.AudioContext = window.AudioContext || window.webkitAudioContext;
    var audioContext = new AudioContext();
    var analyser = audioContext.createAnalyser();//x

    // Create an AudioNode from the stream.
    var mediaStreamSource = audioContext.createMediaStreamSource( stream );

    // Connect it to the destination to hear yourself (or any other node for processing!)
    mediaStreamSource.connect( audioContext.destination );
    analyser.connect(audioContext.destination);
}

navigator.getUserMedia = navigator.getUserMedia || navigator.webkitGetUserMedia || navigator.mozGetUserMedia || navigator.msGetUserMedia;
navigator.getUserMedia( {audio:true}, gotStream, function(err){ console.log("Error getting audio stream!"); });

/*
navigator.getUserMedia = ( navigator.getUserMedia    || navigator.webkitGetUserMedia ||
                       navigator.mozGetUserMedia ||navigator.msGetUserMedia);
var aCtx;
var analyser;
var microphone;
if (navigator.getUserMedia) {
    navigator.getUserMedia({audio: true}, function(stream) {
        aCtx = new webkitAudioContext();
        analyser = aCtx.createAnalyser();
        microphone = aCtx.createMediaStreamSource(stream);
        microphone.connect(analyser);
        analyser.connect(aCtx.destination);
    }, function (){console.warn("Error getting audio stream from getUserMedia")});
};*/