PairDrop/app/elements/sound-notification/sound-notification-behavior.html

<link rel="import" href="sound-notification.html">
<script>
'use strict';
Snapdrop = window.Snapdrop || {};
Snapdrop.SoundNotificationBehavior = {
    sounds: function() {
        var sounds = document.querySelector('sound-notification');
        if (!sounds) {
            sounds = Polymer.Base.create('sound-notification');
            document.body.appendChild(sounds);
        }
        return sounds;
    },
    attached: function() {
        //lazy load sound files
        setTimeout(function() {
            this.sounds();
        }.bind(this), 1000);
    },
    playSound: function(e) {
        this.sounds().play();
    }
};
</script>