What you are describing is the pilot adjusting something in the cockpit of the Spit 5, or a noise associated with the starter. There was no crowd there for anyone to be laughing/ The K4 is prop noise, and since you said you hear a rubbing of cloth it makes me think your sound system is not up to par (and you have a very active imagination). Panzer 4F is from idle to engine shutdown. Engine idle is recorded from inside the tank. Shutdown is recorded at the exhaust.
It's okay Vudu, not everyone is going to have good speakers or headphones, but what you are describing is not in there. The K4, Spit 5, and Panzer 4F were recorded on a Marantz field recorder. Not a cell phone. The mic is a Sennheiser MKH-416. These are industry standard devices and a long shot from cell phones. I suggest you get a great pair of headphones and try again.