For whatever reason, bots are omniscient as long as you have an unsuppressed gun, even if you have never fired a shot. You can be sneaking around in socks on carpet and as long as you don't have a suppressor, bots will magically know where you are. You can see this in action when your teammate is one floor below or above and you walk into a room with a bunch of bots staring at the floor or ceiling. Sticking a suppressor kind of turns them into lobotomites.