The National Aeronautics and Space Administration (NASA) released the results of a study that determined how annoying the ‘bzzz’ of unmanned aircraft systems (UAS or drones) really is to the public on the ground below. NASA researchers compared the noise generated by drones to that of cars, and found that indeed, there was a greater degree of annoyance with drone noise than cars by the public at large. The report, “Initial Investigation into the Psychoacoustic Properties of Small Unmanned Aerial System Noise,” deals with more than just the annoyance level of drone noise, but also analyzes the effects on the environment around the drone. Because the noise of drones is unlike that of other aircraft, and because there are not yet other studies on this issue, NASA researchers are trying to record the noises of various types of drones (known as a ‘psychoacoustic test’) and analyze that data. This could help to create better technologies and designs for drones to limit the noise (and the annoyance) that drones bring to our airspace. Not only did researchers in this study record the noise from drone flights, but they also recorded the noises from a passenger hatchback, utility van and a diesel-powered box truck. They also incorporated computer-generated noises of a quadcopter and a small civil aviation plane.
The human subjects—38 people who were not told the sources of the sounds, were asked to rate each noise from not at all annoying to extremely annoying (with slightly annoying, moderately annoying and very annoying in between). Most subjects noted that they found the high-pitched noises to be more annoying than the low-pitched ones, as well as the noises that appeared to linger were also generally described as more annoying. NASA researchers are still reviewing this data and will certainly conduct more tests. One issue with this study could be, according to researchers, that the subjects were familiar with the noise of a car as opposed to the buzzing of a drone.
This is certainly an important issue for the commercial drone industry, so that the consumer public on the ground below will accept the operation of drones above. And according to NASA researchers in this study, flying the drones higher may not be the only solution –design revisions and noise reducers may alleviate the annoyance and lead to more acceptance by the public at large. There will likely be more studies to come in this subject area as more drones hit the skies.