Flash MX Sound Object Tutorial - Page 6

   //
   firstSound = new Sound(firstSoundMc);
   firstSound.attachSound("firstSound01");
  
  //
   secondSound = new Sound();
   secondSound.attachSound("secondSound01");
  
  //

As in the above example, one sound object was defined on the _root timeline as being assigned as a child of the movie clip "firstSoundMc". The other, secondSound, was not assigned to any movie clip. Note how these two sounds are stopped in the following example:

For firstSound:

on(press) {
  firstSound.stop()
}

For secondSound:

on(press) {
   secondSound.stop()
}

They are stopped exactly in the same manner. However, because "firstSound" was assigned to be the child of the movie clip "firstSoundMc", the stop call to the "firstSound" sound object only stops sounds associated with the movie clip "firstSoundMc". All other sounds continue.

On the other hand, by pressing the stop button for "secondSound", which was not assigned to a movie clip, it will stop all sounds, including sounds assigned to a specific movie clip. This can be convenient if you want to stop all sounds or control the volume or panning for all sounds. The Flash documentation even recommends creating a sound object with the instance name of globalSound - just for this purpose. There is nothing magical about that instance name. It's all in the way the sound object is defined.