How quiet would an electric plane be?
From my understanding, the engine and it's inner workings contribute a good amount to the noise. How much of what we hear is caused by the prop tips going supersonic? The constant breaking of the speed of sound becomes a limitation in terms of decibels.
Would using larger slower props be a solution?
This is a good topic because it starts getting into the real sustainability of the industry.
engines with geared props are much much quieter. A few months ago we had some people camping at the airport for the American Barnstormers tour, and I had an early morning flight. When I took off I passed within 1000 feet straightline from their tent at full power, and they never woke up.