If you have another player that is, for example, 1 km away from you, and you set enableSimulation false on its unit, any further sound from his weapon (like firing and reloading) will be played at full volume as if he was standing next to you, even if he is still 1 km away and has not moved.
Even if the player's position is not being updated anymore due to simulation being disabled, the gun sounds should still be playing the expected way, i.e. as if he was standing still 1 km away with simulation enabled.