One is in DSS format, and to hear this version
you will need to download
the software using this link.
The other is in MP3 format and to hear this
version you will need to try your own computer's audio software. It can
almost certainly play an MP3 file.
This file is very large -- 57 megabites. That means you can only get
access to it easily if you are on a fast line at work or have cable access
to the internet at home.
So, if you think you have a long term interest in audio files, do download DSS to your home computer.