It's a bit weird how firing a gun will sometimes trigger a reaction from NPCs but they will happily sleep through it.
This simply makes them wake, bark out a "Woah!" type response, then probably go back to sleep. It is possible to make them trigger combat with the firer but I think this wouldn't be much fun.
As detailed in the video, "Loud" weapons trigger it more easily than "Normal" ones. So the OWB weapon is loud, whereas the humble 9mm is "Normal". I mean yes a 9mm probably would wake someone from much further away, but the game world is condensed and I think this is appropriate. Let me know if it needs to be tweaked!
Only listens to the player's shots currently, but can easily be changed to anyone firing - companions or NPCs.
Instructions
Install requirements and use MO2 or place in Data/
Requirements
Wakey Wakey
Main file.