You need to do something like this (if you use jQuery)
$('#elem_audio').bind('canplay', function() {
this.currentTime = 10;
});
or in Javascript
var aud = document.getElementById("elem_audio");
aud.oncanplay = function() {
aud.currentTime = 10;
};
The reason behind for this setup is you need to make sure the audio is ready to play.