You can easily figure out if a loud sound happened close or afar. The high frequencies get attenuated faster with distance. Up close, a semiauto or auto weapon has that telltale metal-on-metal clicky component which may even almost dominate. The farther you get, the more dull it sounds. From yet more afar, there are echoes and reverbrations from the buildings and other structures around that smear the sound further.
Same with a lightning. Up close one is a loud CRACK. The further away it gets, the more it is a deep rumbling.
Also, an alternative response to being stressed out by loud sounds and wondering is to shrug it off and file away for optional correlation if it'd repeat too often. As someone prone to anxieties, I can first-hand appreciate the wisdom of not worrying at the slightest provocation. Takes some self-training, though, but it is generally worth it. "Need more data" beats squarely having a panic attack, even the mild ones suck.
Tried to think about guns in games. Went through some somewhat-drunk free associating, and ended up sketching a knockoff of a commercial simulator which uses pneumatic piston to simulate recoil. Saw it on a military tech fair here, was neat, they always have a fairly long queue. (Todo: ask the guys from the Factory if they don't have a spare jig actuator and a solenoid valve). Could be handy for Oculus Rift... Tried some 3d printing with elastomeric polypropylene, just today, and the results are encouraging and it seems it works and could be potentially used for gaskets and maybe even pneumatic/hydraulic piston seals so maybe the actuators could be even made just from a length of pipe and a 3d-printed piston/seal...Who knows yet if such seals actually seal, tests have to be done.
Don't drink and design