Regular.easeOut the sound, please!

This might be the first concrete piece of code I've posted here. While finding myself writing a sound fade routine for the 100th time over again, I decided that I need to take action and finally add another class to the utils package. First I thought I'd go with the old setInterval thing and just stick it in there. But then I thought about the Tween class. And of implicit getters and setters. And if the getting/setting would work with the array access operator that Tween uses.
Well it works.
So without further due I give you the sound volume tween class:

import mx.events.*;
import mx.transitions.Tween;
import mx.transitions.easing.*;

class utils.sound.ExtendedSound extends Sound
{
 public function addEventListener() {};
 public function removeEventListener() {};
 private function dispatchEvent() {};
 private function dispatchQueue() {};

 private var __sndVolume: Number;
 private var sndTween: Tween;


 public function get sndVolume(): Number
 {
  __sndVolume = getVolume();
  return __sndVolume;
 }

 public function set sndVolume(inVol: Number): Void
 {
  __sndVolume = inVol;
  setVolume(__sndVolume);
 }

 /*
 *  @usage: var snd = new ExtendedSound(someMovieClip); snd.fadeTo(25, 3);
 */
 public function ExtendedSound(_args)
 {
  super(_args);
  trace(toString()+'.NEW > ');
  EventDispatcher.initialize(this);
 }

 public function toString(): String
 {
  return 'utils.sound.ExtendedSound';
 }

 public function onFadeFinished():Void
 {
  trace(toString()+'.onFadeFinished > ');
  dispatchEvent({target: this, type:"onFadeFinished"});
 }

 public function fadeTo(inTargetVol: Number, inDuration: Number)
 {
  if(inTargetVol == sndVolume){
   onFadeFinished();
   return;
  }
  inTargetVol = (inTargetVol < intargetvol =" (inTargetVol"> 100) ? (100) : (inTargetVol);

  sndTween = new Tween(this, "sndVolume", Regular.easeOut, sndVolume, inTargetVol, inDuration, true);
  var _this = this;
  sndTween.onMotionFinished = function(){
  _this.onFadeFinished();
  }
 }
}