Let's try this:
To download these files using a Mac:
If you're using a PC, then just point at the link and press your RIGHT mouse button rather than the left. A similar menu will pop up by your cursor.
This will initiate the download of these files to your computer and you simply pick a location where you want to store the files.
http://www.si.umich.edu/ICOS/temp/20050319_A.mp3
http://www.si.umich.edu/ICOS/temp/20050319_B.mp3
http://www.si.umich.edu/ICOS/temp/20050321_A.mp3
http://www.si.umich.edu/ICOS/temp/20050321_B.mp3