Drone Companies Test Quieter Designs as Deliveries Expand

As delivery drones become more common, companies are exploring ways to reduce the noise they make. Amazon Prime Air is expanding to nearly 500 US cities and towns, while Amazon says it is working to make its fleet quieter.

Residents have raised concerns about the sound. Ashley Schmidt, who lives in North Garland, Texas, says drone noise has kept her from spending time in her garden and cycling to nearby parks. Antonio Torija Martinez, an acoustic engineering and psychoacoustics professor at the University of Salford, says drone noise can stand out even when overall sound levels are relatively low. Drones fly at low altitudes and may pass directly over homes, exposing communities to aircraft noise they have not previously experienced.

London-based startup Greenjets says its propulsion system can reduce drone noise by at least two thirds. It encloses spinning blades inside a pod and also uses slower rotor speeds and materials intended to reduce vibration noise. The company says its technology has been used by police and harbour security teams in Germany, and by conservationists in Africa tracking poachers.

Sharrow Engineering, founded by Detroit entrepreneur Greg Sharrow, is developing quieter drone rotors based on twisted, loop-shaped propeller blades. Sharrow says the company has validated the technology in drone applications and that it is “dramatically quieter.”

Research fellow Robert Tollast of the Royal United Services Institute says US Special Forces have shown experimental interest in reducing drone sound. He says speed tends to take priority over quietness for larger drones used in the Russia-Ukraine war.