simple implementation of pooling audio elements

sfx.js

define(function() {

  var pools = {};
	var tags = {};
	var manifest = {
		'laser': ['sfx/laser.wav', 2],
		'explosion': ['sfx/explosion.wav', 8]
	};

	function createTag(src, whenReady) {
		var tag = new Audio;
		tag.src = src;
		// tag.autoplay = false;
		// tag.preload = 'none';

		tag.load();
		tag.addEventListener('canplaythrough', whenReady, true);

		return tag;
	}

	function TagPool(src, channels) {
		this.pool = [];
		this.channels = channels;
		this.nextIndex = 0;

		var waitingForReady = channels;

		for (var i = 0; i < channels; i++) {
			this.pool[i] = createTag(src, function() {
				waitingForReady--;
				if (waitingForReady === 0) {
					console.log('the pool for ' + src + ' has loaded');
				}
			});
		}
	}

	TagPool.prototype.next = function() {
		if (this.nextIndex >= this.channels) this.nextIndex = 0;
		var tag = this.pool[this.nextIndex];

		// is the tag currently playing? if so, reset it
		if (tag.currentTime != 0) {
			// I can't find any other way to reset
			// the sound
			tag.load();
		}

		this.nextIndex++;
		return tag;
	};

	function initialize() {

		Object.keys(manifest).forEach(function(key) {
			var options = manifest[key];
			var src = options[0];
			var channels = options[1] || 1;

			pools[key] = new TagPool(src, channels);
		});

	}

	function play(key) {
		var pool = pools[key];
		if (!pool) throw new Error('sfx: tag pool for ' + key + ' does not exist!');

		var tag = pool.next();
		tag.play();
	}

	return {
		initialize: initialize,
		play: play
	}

});