With screaming two strokes and gassers in the air, and a four stroke being tuned in the pits? Well maybe younger ears could hear that helio, but not mine. In general I agree with you. But to point out that around hear to never fly when you can see an airplane in the air means almost never flying. To not fly when you can hear an airplane, means flying maybe 20% of the time. But not flying when a plane is below pattern altitude means we can fly 95% of the time.

You have very very good ears to hear an A-10 coming. They were designed to be very quite when approaching.