"If a tree falls in a forest and no one is around to hear it, does it make a sound?"

Apparently in Arma 3 YES and this causes performance issues.

When one spawns in a vehicle and puts enablesimulation false and hideobject true into its init line, one expects this object NOT to consume resources. However I have found that when spawning in hundreds of vehicles, the FPS drops dramatically which is unexpected. Take these classnames for example:

Starting at 56FPS
C_Boat_Civil_01_police_F FPS: 53
Box_NATO_Wps_F FPS: 56
B_MBT_01_arty_F FPS: 27
B_Boat_Transport_01_F FPS: 56
C_Offroad_01_F FPS: 28
B_Heli_Light_01_F FPS: 53

I found that the sound eventhandler engine and Phsyx were not being disabled with enablesimulation false. Until now, this was only an assumption. I have since started hacking the config.bin of vehicles and trying to figure out why land vehicles (cars) drop FPS much more than air or boats. I have found two areas of simulation that are not disabled with enablesimulation false:

class Sounds {}; (7FPS change in my testing when omitted from config.bin)

simulation = "carx"; to simulation = "car"; (11 FPS change, in config.bin which dictates if Physx is used on the vehicle) https://community.bistudio.com/wiki/Arma_3_Cars_Config_Guidlines

I am not sure how the Arma 3 sound engine works, however it is my assumption that they rely on Event Handlers which still simulate per vehicle even with enablesimulation false.