Use stuffit to open the files!

you can download a version of stuffit at this website:
http://www.dnaseq.co.uk/Downloads.html

just right click on the "Stuffit Expander for Windows (version 7.0)" and save destination as...

But how you open the .snd files after they´ve been unpacked, is a question i can't answer!
I've tried just about everything, but I can't find a program which can read these .snd files on my pc. even though alot of programs claim to be able to convert .snd files to wav or mp3, none of the programs i've tried has been able to read nor convert these shitty files!:(