Quote from SkackyOh that's nothing, wait until you're in the Cathedral.
I played the original Thief long long ago, but it was a weird pirated version with all the NPC sounds removed... except the Haunt sounds. So I was like, "whoa, NPCs make sounds?!" and was freaking out from all the chains rattling and couldn't take more than 10 steps into the Cathedral before quitting. This time I won't be afraid though!