I believe that Stukas were fitted with gadgets called Jericho horns to make them sound scarier!
Mind you a hooter might not be such a bad idea. A guy I know was trying to dead stick onto a golf course after an engine failure when a bunch of geezers In loud pullovers and "Rupert the Bear" trousers marched onto his chosen landing point. Despite shouting at them he could not get their attention. So he had swerve to avoid them and ended up nosing over in the crop along side the fairway.
