Exporting Sounds For AS

I’ve just started adding some sounds to a game I am making, but can’t figure out how this is affecting the filesize of the final swf.

I have a wav file that is 90kb. I imported it to the library and then chose to “Export For Actionscript” from the linkage menu. Everything works and the sound plays, yet the overall swf size is still only 55kb. This is little or nothing above the size of the swf without the wav file, which I don’t understand. Obviously I’d be happy if the swf stayed at this size, it just doesn’t seem to make any sense to me?

Can anyone offer some advice on how flash manages to embed a 90kb file with no detriment to file size?