> A related aspect is that electric planes are much more quiet.
I'm not so sure! Have you ever heard the sound of twin-turbo regional airplanes in small airports? That sound is not from the turboprop engine, but from the propeller itself. Electric planes do have propellers and propellers are usually very loud. Actually much louder than turbofans!
Making propellers quieter has been an active field of research in fluid dynamics for decades but it's a very hard problem.
Many smaller propellers can replace a few bigger ones. They'll make noise but not nearly as much as huge twin props. Another thing is that electrical propellers only make noise when you need them to produce thrust. Most traditional props produce noise just sitting on the ramp waiting for their oil temperatures to rise or while slowly taxiing to the runway. Another difference is that the high pitched whine of an electrical engine is very different from rumbling of a jet or piston engine. As I'm writing this, I hear a jet plane taking off from an airport 6 miles away from my house. I doubt I'd be able to hear an electrical plane from that distance.
Illustrative anecdote: when you hear a lightplane or ultralight with a high-rpm 2-stroke engine and a reduction drive turning a slower prop, up close you hear the high whine of the engine, but when it gets farther away you hear only the prop, a much lower sound. It's amazing how much of the sound is from the propeller.
I'm not so sure! Have you ever heard the sound of twin-turbo regional airplanes in small airports? That sound is not from the turboprop engine, but from the propeller itself. Electric planes do have propellers and propellers are usually very loud. Actually much louder than turbofans!
Making propellers quieter has been an active field of research in fluid dynamics for decades but it's a very hard problem.