speaking of pinball knockers. I think the "electronic" knocker noise/distorted shriek that I have from my P2000's and I'm told on the later games is the worst sound I can imagine. The physial coil shaft hitting wood can scare you but the other noise just makes me look up to see if my pin has just blown up. I've gotta see if I can turn that off in the settings.
Nothing like the knocker slamming into the cabinet or headbox when you least expect it!!!