Sorry I can't help much with this problem, especially as it's not a program I'm familiar with.
No disrespect to anyone, but are we sure it's a audio file and not a movie file?
or, have you tried changing the extension to say, .mp3 (after making a copy of one of the files)
it might be worth trying, but on the other hand, they are something that you didn't know you had, so will you miss them if you throw them away?
But no-doubt like myself, you are now curious and wont give in to easily.