Yes, these files are encapsulated 'snd ' resources. You will need a program to run on a Macintosh that will convert these files to AIFF or WAV files.
Try this neat little program to convert them:
http://www.versiontracker.com/dyn/moreinfo/macos/9833
You should copy the .HQX file to a PC-format floppy disk, then copy the .HQX file onto the old Mac's hard drive. From there, double-click the .HQX you just made in the hard drive. This should launch StuffIt Expander and expand into the real application you can use.
If your Mac says something about not being able to find a program to open the HQX file, let us know.
Open the program first (SoundConverter Pro) and select "Preferences" in the File menu. UNcheck "Downsample Sounds[...]" and "Convert Sounds[...]". Click OK.
Now, go back and select all of your good old sounds and drag them on top of the SoundConverter Pro icon. A message box should pop up. Select the top option (AIFF format). The program should proceed to convert all of your sounds into AIFF format. These new files can be copied to PC-format floppies and copied into a PC. You may have to add the ".AIF" filename extension for Windows to recognize the files.
Edit
Sorry, Scott Baret, I took so long to post this that yours got in before mine. There is a multitude of different programs you can use to make the conversion, we each just happened to pick separate ones.