Fujii
You're missing my point.
The big fly in the ointment is the energy density of what ever is used as a power source. Petrol (gasoline) has 53 times the watt/hour capacity of a lithium ion battery. In other words for every kilo of petrol you need 53 kilograms of lithium ion battery. With current technology an electric powered aircraft doesn't make sense.
So far as the noise goes, I'm not thinking of the horses. Noise pollution is becoming a bigger and bigger issue, I don't see the noise these things will make as being accepted by the general population.