How to sound with web audio api?

I'm trying to get the following code to work. I trigger the sound with arrow left, and I want it to keep playing until I release the key. I'm having a bit of a problem finding out what the scope of each sound has, so I can send it a stop or .pause command.

window.AudioContext = window.AudioContext || window.webkitAudioContext;

function BufferLoader(context, urlList, callback) {
    this.context = context;
    this.urlList = urlList;
    this.onload = callback;
    this.bufferList = new Array();
    this.loadCount = 0;
}

BufferLoader.prototype.loadBuffer = function (url, index) {
    // Load buffer asynchronously
    var request = new XMLHttpRequest();
    request.open("GET", url, true);
    request.responseType = "arraybuffer";

    var loader = this;

    request.onload = function () {
        // Asynchronously decode the audio file data in request.response
        loader.context.decodeAudioData(
        request.response,

        function (buffer) {
            if (!buffer) {
                alert('error decoding file data: ' + url);
                return;
            }
            loader.bufferList[index] = buffer;
            if (++loader.loadCount == loader.urlList.length) loader.onload(loader.bufferList);
        },

        function (error) {
            console.error('decodeAudioData error', error);
        });
    }

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

    request.send();
}

BufferLoader.prototype.load = function () {
    for (var i = 0; i < this.urlList.length; ++i)
    this.loadBuffer(this.urlList[i], i);
}

/// setup audio context and start loading samples
var actx = new AudioContext(),
    blst,
    bLoader = new BufferLoader(
    actx, [
        'http://ift.tt/1fBE5e1',
        'http://ift.tt/1WOAafM',
        'http://ift.tt/1fBE6yu'],
    done),
    isReady = false;

/// start loading the samples
bLoader.load();

/// when samples are loaded update status
function done(bl) {
    blst = bl;
    isReady = true;
    $('#status').html('Ready!');
}

/// this sets up chain so we can play audio
function play(i) {
    var src = actx.createBufferSource();
    src.buffer = blst[i];
    src.connect(actx.destination);
    //src.loop = true;
    src.start(0);
    playing = i;

   var output = '';
    for (var property in actx) {
       output += property + ': ' + actx[property]+'; ';
    }
    console.log(output);

}

function stop(i) {
    //src.stop(context.currentTime);
    //src.stop(i);
    console.log("stop " + i);
}

/// check keys

var arrowKeyDown = false;

$('body').keydown(function(e) {
    if (e.which == 37 && !arrowKeyDown) {
        arrowKeyDown = true;
    play(0);
        // ...
    }
});

$('body').keyup(function(e) {
    if (e.which == 37) {
        arrowKeyDown = false;
        stop(0);
    }
});





$(window).bind("keydown", function (key) {
    if (!isReady) return;

    var output = '';
    for (var property in key) {
       output += property + ': ' + key[property]+'; ';
    }
    //console.log(output);

    switch (parseInt(key.which, 10)) {
        case 65:
            play(0);
            break;
        case 83:
            play(1);
            break;
        case 68:
            play(2);
            break;
    }

})

$(window).bind("keyup", function (key) {
    if (!isReady) return;

    switch (parseInt(key.which, 10)) {
        case 65:
            stop(0);
            break;
        case 83:
            stop(1);
            break;
        case 68:
            stop(2);
            break;
    }

})