Do suppressors work on NPCs?

Hi there, new player here. I basically only go on PvE island until i get the hang of things. While the first couple of raids i'd get bodied by the NPCs, i've learned more about the locations and have gotten better at dealing with them, although I still don't get why sometimes I get spotted and 1-2 shot from miles away. Trying to find the best ways to deal with NPCs and since i've found a couple suppressors i was wondering if they actually help with them at all or if as soon as they get shot they realize "oh he's 27.4 degrees to my right, 143 feet away". Appreciate all the help I could get!