leave second function(mouseout) blank so audio plays only when entering mouse into "a" tag
$("a").hover(function(){
var audio = $('<audio>', {
autoPlay : 'autoplay',
controls : 'controls'
});
addSource(audio, 'audio/ding.mp3');
addSource(audio, 'audio/ding.wav');
addSource(audio, 'audio/ding.ogg');
},function(){
});