[Nutrox]

The Sound class also has getBytesLoaded() and getBytesTotal() methods, so you can check the load progress easily enough if you don't want to stream the audio.

var mySound:Sound = new Sound();
var loadInterval:Number;
 
function loadSound(url:String):Void
{
   if (loadInterval)
   {
      clearInterval(loadInterval);
   }
   mySound.loadSound(url);
   loadInterval = setInterval(this, "checkLoadProgress", 100);
}
 
function checkLoadProgress():Void
{
   var percent:Number = 0;
   var bLoaded:Number = mySound.getBytesLoaded();
   var bTotal:Number = mySound.getBytesTotal();
 
   if (bLoaded && bTotal)
   {
      percent = (100 / bTotal) * bLoaded >> 0;
   }
 
   if (percent == 100)
   {
      clearInterval(loadInterval);
      loadInterval = null;
 
      mySound.play();
   }
}
 
//
 
loadSound("ambience.mp3");