ActionScript 3.0 :: How To Close Sound Object

I'm using Flash CS3, running code in ActionScript 3. I use the Loader class to load a child SWF file, which then takes over the entire area on my website that is reserved for Flash. If the user decides to stop watching the SWF file before it is completed, he hits the "close" button within the child SWF, ultimately causing the Loader.unload() method to be executed. So far, so good, only the sound from the remaining portion of the SWF file keeps playing. According to the Flash Docs for the Loader.unload() method:

"As a best practice, before you unload a child SWF file, you should explicitly close any streams in the child SWF file's objects, such as LocalConnection, NetConnection, NetStream, and Sound objects. Otherwise, audio in the child SWF file might continue to play, even though the child SWF file was unloaded."

It then gives an example that assumes you already have access to the Sound object, so closing the Sound object is done by: mySound.close();

The only problem is that I have no idea how to access the Sound object when I use the Loader.load() method. I can't seem to find anything in the documentation that tells me how to find the Sound object after calling Loader.load(). As a temporary fix, I modified the target SWF file so that when the "close" button is hit, it calls the "stop()" function; however, this only stops the sound, it does not close the associated Sound object, and I presume it continues to lurk around in memory with nothing useful to do. (When the user hits the "close" button in the child SWF file, it creates a "bubbling" event so that the Loader class can call the Loader.unload() method on it.) I've attached code for your reference.