In comparing the Volocopter noise to helicopters it would be something with no main rotor noise and 18 heavily loaded open tail rotors: * https://en.wikipedia.

In comparing the Volocopter noise to helicopters it would be something with no main rotor noise and 18 heavily loaded open tail rotors: * https://en.wikipedia.org/wiki/Helicopter_noise_reduction#Tail_rotor_noise https://en.wikipedia.org/wiki/Helicopter_noise_reduction#Tai... My guess would be that the noise wouldn't carry as far due to the higher frequency but would be very loud closer in, again due to the higher frequency.