Greenjets has designed a propulsion system that the London-based business claims can reduce drone noise by at least two thirds. Standard drones use spinning propellers that slice through open air to create a high-pitched buzz, but Greenjets encloses spinning blades inside a pod to muffle the sound and direct the noise away from the ground.
Schmidt is one of a growing number of people living with the noise of drones dispatched by companies including Amazon and Walmart as they seek to speed up home deliveries. Even in cities where noise is already a steady part of life, the sound of drones seems to irk in a particular way because the sudden whine of a rotor can pierce the everyday hum while traffic blends into the background.
Smaller drone delivery services are popping up too, allowing customers in some US cities to order flying treats from their local pizza joint or ice cream parlour. Companies at the forefront of drone deliveries say they are also working to reduce the noise of their fleets.
Making quieter drones is not just about keeping the noise down for neighbours who are already sick of airborne deliveries, as battlefield drone operators also have good reason to keep the noise down to avoid alerting the enemy of the approach of their unmanned vehicles.
Complaints about the sound of drones are likely to grow according to Schmidt, who warns that the problems are currently localised in some areas.