使用ajax的jQuery通知声音

Question

I have a php file that returns new items from db and using ajax, i update a div with number of new items.

In order to make it look a bit like facebook, i have inside a setInterval(3000 ms) the ajax call.All ok here. Now i want to play a sound when new items comes up.

My code looks like this:

$.ajax({
  type: "POST",
  url: "script.php",
    data: { action : somedata },
    cache: false,
    success: function(html){
      if(html > 0) {
        // update div
      }else{
        //do nothing
      }
    }
})`

I googled how to play a sound in jQuery, and i got a working solution:

var audioElement = document.createElement('audio');
audioElement.setAttribute('src', 'notification.ogg');
audioElement.setAttribute('autoplay', 'autoplay');

$.get();
audioElement.addEventListener("load", function() {
audioElement.play();
}, true);

If i put the previous code here:

if(html > 0) {
here
}

the sound is played, but there's a problem. It's played every 3000ms. I don't want this. I want to play it only when a new item comes up in the db, and not every time the ajax call is made.

How can i achieve this?