It's difficult to know what is a rational noise level since I'm already half-deaf from uh let's call them "indiscretions" in my younger years (both airplane and music related). But I'm pretty sure the afterthought-cockpit they pasted on to the top of the 74 doesn't get in under that bar. Headsets off is bearable in cruise, but one does begin to wonder what the mic is even for down low.
Although I suppose it's all relative. A profound portion of my hearing-damage certainly comes from once...*ONCE* operating a Beech 99 without a headset. It was a post-MX flight, and I had left my headset in the car. No worries, we're just taking it around the patch, should be fine. Fast-forward to 30 seconds in to the flight and it was very clear that this was a *serious* mistake. The mechanic in the right seat is clearly screaming at me, like I can tell by how the tendons in his neck are flexing, but I can't hear a damned thing other than the prop that's like 4ft from my dumb noggin.
Uncivilized is what it is. Unlike, it seems, the MD. I finally understand. Plus I hear the VNAV (or whatever it's called) is pretty great.