I watched a Eurogamer gameplay vid yesterday. There is the *pip* *pip* *pip* of grenades, and a synthetic sound - not a screech or whine - that I understood was the ammo running low. Personally I didn't find it at all disconcerting, as it's a sound to inform the troops, and you'd want it to be different and stand out. It's like all the bleeps and boops that abound with button presses.