How greenery exposure influences noise perception across geographic contexts

Abstract

While growing attention has been paid to audio-visual interactions, the findings on the role of greenery exposure in noise perception are inconsistent. The inconsistent conclusions may stem from the uncertain geographic context problem. Building on two distinct mechanisms identified in past studies (i.e., restorative and masking effects and the audio-visual congruency effect), this study aims to unveil how greenery exposure influences noise perception across geographic contexts. Employing portable devices and subjective sensing tools, we collect people’s real-time sound exposure, greenery exposure, and noise perception during their real-life contexts. Subsequently, interpretable machine learning methods are used to investigate the global and local effects of greenery exposure on noise perception. The results include: i) a significant and positive association between real-time sound level and perceived noise level was observed, with greenery exposure significantly moderating the association; ii) notable non-linearity in such relationships was also identified, with consistent sound level and greenery exposure thresholds across geographic contexts. While the restorative and masking effects dominate, their magnitudes vary, and the audio-visual congruency effect can be identified locally. The prevalence of the two distinct mechanisms is associated with specific urban functional contexts. The findings can serve as scientific references for policymakers on noise governance and greenery design.