Delivery drones from companies including Amazon and Walmart’s vehicle supplier Wing are drawing noise complaints in the US, and engineers are racing to quiet them. Amazon Prime Air is expanding to nearly 500 cities and towns, while residents like Ashley Schmidt say the buzz has driven them indoors.
Schmidt, 44, an administrative assistant in North Garland, a Dallas suburb, has largely abandoned her garden and her bike rides to local parks. She told Yahoo that the drones emit this very annoying buzz
that triggers her fight-or-flight response.
Why a Drone’s Whine Cuts Through City Noise
Antonio Torija Martinez, a professor of acoustic engineering and psychoacoustics at the University of Salford, says the sound is particularly noticeable, even when overall sound levels are relatively low
. Drones fly low. They can pass directly over homes, he says, exposing communities with little prior aircraft noise.
He cites research showing people react strongly to sounds they find novel, intrusive or frequent
. Residents who benefit from the service may mind less.
His warning: At the moment we are seeing some of these problems localised in some areas, but… as the drone sector expands, more and more of these complaints will happen.
FAA Says Communities Share Responsibility
The FAA regulates commercial drones in the US and has been criticized for permitting noisy delivery operations. The agency says operators and local community leaders hold primary responsibility for handling community concerns.
Amazon and Wing Point to Quieter Propellers
An Amazon spokesperson says the company has made measurable sound improvements
. Its newest designs use custom propellers that produce almost half the perceived sound of the prior generation, with a milder tone
. Amazon Prime Air delivers items that fit in a shoe-box-sized space. It has also launched in and around Darlington, in northern England.
Wing, which supplies drones for Walmart deliveries, says its propellers are designed to minimize noise. It also varies flight paths so no single home or neighborhood gets repeated overflights.
Greenjets Boxes In Blades as Sharrow Clips the Tips
London-based Greenjets encloses spinning blades in a pod that muffles sound and directs it away from the ground. It also uses slower rotor speeds and vibration-damping materials. The company claims at least a two-thirds noise cut.
Darren James, its future technologies lead, says the aim was to tackle both noise level and the frequency of that noise
. Its technology has been used by German police and harbor security teams, and by conservationists in Africa tracking poachers.
Detroit-based entrepreneur Greg Sharrow was set on the path to quieter drone design in 2012. He needed to film a violinist from a tricky angle and found a drone would be far too noisy. I knew that most of the noise from the drone was coming from the propeller, not the motor,
he says.
Military Drones Prize Speed Over Silence
Robert Tollast, a research fellow at the Royal United Services Institute, says US Special Forces are interested in quieter drones at an experimental stage. For larger drones in the Russia–Ukraine war, though, speed comes first: Make it faster, not less quiet, seems to be the approach.