It's my guess they are spam or else you do not have the correct audio codecs to play the files.

Check this advice: http://www.gnutellaforums.com/downlo...wire-spam.html & make a note of typical audio spam sizes. Also about the audio bit rates compared to file size: mp3 Bit-Rates Versus File Sizes (click on link)

You could try a different player to play those files.