Redesign makes drones quieter and less annoying without losing thrust

By David Hambling

Drones could soon drone less. A redesign of the rotor blades could reduce the noise made by drones and make them less irritating.

The buzzing sound from drones comes mostly from the way the fast-rotating blades slice through the air. Researchers at Australia’s Royal Melbourne Institute of Technology, working with Melbourne-based aerospace company XROTOR, are looking to suppress the buzz by redesigning the blades.

The researchers focus on inter-frequency modulation, the sum of many different frequencies produced by rotor blades and which is responsible for …