Don’t talk to noisy drones – Acoustic interaction with unmanned aerial vehicles

Abstract

Common applications of an unmanned aerial vehicle (UAV, aerial drone) utilize the capabilities of mobile image or video capturing, whereas our article deals with acoustic-related scenarios. Especially for surveillance tasks, e.g. in disaster management or measurement of artificial environmental noise in large industrial areas, an UAV-based acoustic interaction or measurement can be important tasks. A sound and speech signal processing at UAVs is complex because of rotor and maneuver-related noise components. The signal processing has to consider various sound sources, and the wanted signals (e.g. artificial environmental noise or speech signals) have to be separated from the UAVs’ own flight and wind noise. The contribution discusses the acoustic scenarios and some acoustic characteristics of a sample UAV, including the effect of flight maneuvers. We recorded speech signals in best practice with regard to the outcome of our preliminary analyses and then conducted objective speech quality measurements and speech recognition experiments with a state-of-the-art recognizer. Aside, the measurability of environmental noise signals is analyzed exemplarily. The article concludes with lessons learned for acoustic UAV interactions or measurements and preliminary thoughts with regard to a novel category of ’low-noise’ UAVs.