Researchers from Nagoya University and Keio University in Japan have estimated a person's stress levels caused by the sound of a flying car passing overhead. The research was published in the Technical Journal of Advanced Mobility in September 2022.1

In the research experiment, participants watched short videos that simulated cars flying in a city. The videos were designed so that the viewers felt like a car was flying 15 meters above them at a speed of 15.5 miles per hour (25 km per hour). To simulate such a scene, the videos used audio recordings of an industrial drone flying at a speed and height similar to the flying car depicted in the videos. Participants watched the video eight times, while the researchers changed the volume of the audio in each viewing to examine how the noise level would affect the participants. Participants' stress levels were assessed using two different measures. First, while watching the videos, a portable EEG device, called a Kansei Analyzer, recorded their brain activity. Second, after watching each video, the participants responded to a written questionnaire.

  • 1. The drone market is booming, as several automobile companies and start-ups develop new personal aircraft. The long-awaited flying car, made famous in films like Blade Runner, may soon be a common sight in cities around the world. But while the automobile industry is busy developing technology to catch up to fantasy, few inventors or science fiction authors have thought much about how noise from the roaring and whirring of flying car engines might affect people's psychological state. Professor Susumu Hara of the Department of Aerospace Engineering, Graduate School of Engineering at Nagoya University, the lead author of the study, points out that in past industrial revolutions, people often prioritized technological advancement and economic demands over social and environmental issues, including noise and air pollution. "Unless technology is well-integrated in our daily lives," he argues, "we cannot expect it to make our society a better place." Therefore, his team conducted an experiment to estimate people's stress levels as if they were living in a world with flying cars.

Susumu Hara, Yasue Mitsukura, Hiroko Kamide, Noise-Induced Stress Assessment ─ On the Difference between Questionnaire-Based and EEG Measurement-Based Evaluations─, Technical Journal of Advanced Mobility, 2022, Volume 3, Issue 6, Pages 81-90, Released on J-STAGE September 07, 2022, Online ISSN 2435-5453, https://doi.org/10.34590/tjam.3.6_8

In recent years, flying car (urban air mobility, UAM) technologies have been actively studied in Japan and other countries. However, the social acceptability of flying vehicles such as UAM and drones (unmanned aircraft systems, UAS) has not been extensively investigated. Social issues often arise when social acceptance is neglected. Thus, novel issues are expected to arise on the advent of the so-called Aerial Industrial Revolution because of the industrial use of drones and commercialization of flying cars. To overcome these issues, herein, the social acceptability of this revolution was evaluated by two different approaches: sociopsychological evaluation using a questionnaire and real-time evaluation by electroencephalograph (EEG) measurement using a Kansei analyzer. The authors experimentally evaluated the applicability of the Kansei analyzer for various sounds including stationary rotor sound and nonstationary metallic sound in the previous study. Different from such an experiment, this study conducted experiments based on the industrial drone sound with four levels of volume. Subsequently, the difference between the stress levels was investigated using the questionnaire and the Kansei analyzer. The result may impact the formulation of the social acceptability survey methods in future.