Unfortunately, I won’t have much time to read the code in the next 2 days. But I saw that “hearing” checks if the weapon “isSilent” to set the “located” state for an actor (if it is not silent).
I guess that only crossbows are silent and, since I’m new to this stuff, I don’t know where to look into the assets for weapon stats and the “mods” (JJ’s) on Nexus don’t show it.
The way the game handles this is as follows (very simplified):
Each faction has a list of actors along with their state (hidden, located, revealed). If you shoot a “non silent” weapon, you become “located”.
What I saw is that this “located” state is not “reset” when moving (and dead Pandorans can still hear you). So once you shoot a “non silent” weapon, Chirons will always know where you are, even if you cross the map without anyone seeing you.
I suppose that they set the “located” status on the actor that shot (that’s why I would have to check the code) rather than a “virtual” actor that was just created to make a “ping” on the map but wouldn’t move.
Once I have time, I’ll try to get to the bottom of it and potentially make my second “mod” 
: pp-realistic-hearing
(all this explains why the Chiron could know where I was in the Thread: Please explain how Mortar Chiron work)
I’ll create a new Thread once I get to read all the code behind “hearing”.