I'm a RL pilot, PPL, on my final hours for CPL. Of course, I don't fly 1500 - 2000hp 3- 4ton props; rather 160hp 700kg ones
lol
We use the headsets with ear cuffs, probably with slightly less noise reduction than WWII ones. Dude, still with a 10x less powerful engine, it's A HELL LOT OF NOISE! If you take the headset off, the noise is unbearable. Also, if I speed up (silly thing, from 100 to 150 mph ) the wind whistles quite well, you can hear a little "clanking" when lowering flaps too. I always imagine what it would sound like to fire guns from that plane. I've never heard anything bigger than an 8mm rifle, firing 3m from me, and I'm sure it would be heard in a plane (less loud, but still), specially the repeating mechanism of an automatic gun.