Here's one I was made aware of recently. I find it to be very relaxing...
B-17 Propeller Noise SimulatorHere's the lead-in on the website:
The noise, without the war
In 1944, before the dawn of the jet age, war birds ruled the skies. Powered by the hum and thrum, and shake and rattle of piston driven propellers, they thundered ever onward to their targets. Their names: the B-17 Flying Fortress, B-29 Super Fortress, Lancaster and Liberator, are still familiar seven decades later!
Turn off the lights, put the headphones on, and crank volume up. Strap yourself into the pilot's seat... and fly back in time!
