There is a metallic sound that all saddle bags make when a horse turns. With the noble saddle (4 bags) it is really amplified when making a turn while cantering (not so noticeable at a walk or full gallop). The effect is not nearly as noticeable wit h other saddles.
It CAN act like a car horn for those insurance scammers to move aside. Unfortunately it doesnt work very well on certain path. Some bastards, in my believe, braced the impact head on. ON PURPOSE. Just to trigger a reason to curse the fuck out of you. 
They never listen. I have had some of the idiots walk straight into the side of my horse while it is perfectly still and they still curse me.