Why give up your position? I've never understood this.
A couple of other scary noises come to mind, one being an ear-shattering ker-boom! followed shortly by the wet kerplopping noise your crime partner makes as his body drops to the floor. Then the remaining bad guy gets to hear the sound of the next shotgun round being chambered. Yep, THAT would be scary.
Personally, I reckon that the sound of a shotgun being charged, especially at night, isn't nearly as impressive as that little *pop! sound made by the igniter cartridge of a flamethrower just before the operator opens up the fuel release valve *trigger*. Also especially at night.
