playbackRate doen't work in Internet Explorer (10?) is it a bug?

Hi, I have a little function to play audio:

<script type="text/javascript">     
function play_sound(url, speed) {     
  var audioElement = document.createElement('audio');     
  audioElement.setAttribute('src', url); 
  audioElement.playbackRate = speed;     
  audioElement.play();     
}     
</script> 

I call this function as follows: onClick="play_sound('audio/S0001.mp3',0.67);"

It works fine in all (most?) browsers except Internet Explorer. I currently have version 10.0.9200.17116, so I don't know if this is a bug/problem exclusive to IE10 or not.

Is this a bug and do I need to wait for the next update and advise my website visitors accordingly? Or is there a workaround that will work on IE in the meantime? Perhaps I (and my visitors) have to install an add-on or change a javascript or security setting somewhere?

Many thanks in davance