Honestly, that was some 25-30 years ago. It was pretty simple to setup back then, but it might not be the same now, especially in Windows.

I forget the type of mic but there are mics specifically designed for picking up vibrations from surfaces (I googled it, they’re called surface mics ffs, could probably use a cheap normal mic without a pop filter tho)

If those use USB or 3.5mm, or can be made to, then plug them in and on windows check the “listen to this device” checkbox and boom, you’ll hear what’s coming through that mic. Adjust the sensitivity to your needs, done

On other OSs you can do it too just as easily but I don’t remember what my Linux distro calls it and if you’ve installed Linux you have enough info from my comment to figure it out methinks