The effects of time-variant characteristics of unmanned aircraft system noise on reported annoyance

Podwinska, Zuzanna; Ramos-Romero, Carlos; Green, Marc; Torija, Antonio J

Abstract

Flight missions of Unmanned Aircraft Systems (UAS) are inherently unsteady due to the complex interactions between the environment (e.g., wind conditions) and the operative flight control system. These interactions result in the unsteadiness of the acoustic footprint, which affects psychoacoustic attributes even during apparently stable operations like hovering. This study investigated how time-varying characteristics of noise produced by hovering multi-rotor UAS affect human annoyance ratings. An in-house framework for synthesis and auralisation was applied to generate a corpus of UAS noise stimuli. The synthesis method allowed the modification of time-variant attributes of both the tonal and broadband components by altering frequency and amplitude modulation parameters. The stimuli were evaluated in a listening experiment in which participants were asked to rate their short-term annoyance in a relative magnitude estimation task. An analysis with mixed-effects linear models revealed that higher modulation depth and lower modulation frequency resulted in sounds rated as more annoying. Additionally, modulation parameters changing over time, particularly aperiodic modulation functions and signals with non-zero slope, produced less annoying sound than constant parameters. Overall, the results emphasise the importance of time-varying characteristics of sound for reported noise annoyance, with potential implications for flight control optimisation of UAS for lower noise annoyance.

• Presentation Conference Type: Conference Paper (published)
• Conference Name: Forumacusticum Euronoise 2025
• Start Date: Jun 23, 2025
• End Date: Jun 26, 2025
• Acceptance Date: Jun 23, 2025
• Publication Date: 2025-06
• Deposit Date: Jul 7, 2025
• Publicly Available Date: Jul 10, 2025
• Peer Reviewed: Peer Reviewed
• Keywords: environmental noise; drone noise; annoyance