Project Heaviside is Kitty Hawk’s latest high-performance electric VTOL vehicle. It is designed to be fast, small and exceedingly quiet. Video shows November 2019 flight test footage from Northern California test site.

http://kittyhawk.aero/heaviside/

Noise levels
80dB - Large city intersection
60dB - Small town intersection
40dB - Rural intersection at night
*38dB - Heaviside at 1500ft overhead*
30dB - Bedroom at night