I don't specifically know this myself, but I know there is a way of opening sounds.dat in Audacity.
Currently, there is no way of actually editing how music works in either AO or AE (which is done by an arrangement of audio samples). I believe it is something to do with what novaman said.
You could, however, edit sounds.dat in Audacity and replace the GameSpeak sounds. This is probably possible, but again I don't know much about it.
Check the "Fun with sounds.dat" thread out (
this thread) as this has the most info.