I used to almost exclusively listen to any kind of audio through headphones. I had a microphone near my desk configured so that it would pass through the vibration of footsteps directly to my headphones. I was rarely startled, no matter what sordid activity I was undertaking.
I swear the footsteps trigger a Pavlov response in me at this point. I can even tell who it is by the footsteps
Pavlov
As in you instantly lose an erection, because you’ve been conditioned to associate footfalls with a ruined orgasm?
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
