Back in around 1990 someone had a, I want to say, KW logging truck when I was working on the wharf and he had a muffler on the starter motor. It was surprisingly quiet. When I was sitting inside the scaling hut, I could see that he started the truck because there was the puff of dust, but if another truck was idling, I couldn't hear the starter. We had a Superliner with a regular screen on the starter and it was the usual loud sound so this other guy's truck was a revelation. His wife or neighbors must have gotten sick of the racket and asked him nicely to knock it off : )
The other thing I like about those starters are the operation - turn the key to start for about 1 second then release it. Engine will still start immediately but the air is conserved and the racket only lasts a couple of seconds.