Linking Visual-Auditory Cues to Restoration: The Mediating Role of Perceived Biodiversity

Due to rapid urbanization over the past five decades, there has been growing interest in the role of biodiversity in supporting human well-being. While previous research highlights the role of landscape biodiversity in psychological restoration, the pathway linking visual and auditory cues to perceived biodiversity-and subsequently to restorative outcomes-remains poorly understood. This study explores how visual and auditory stimuli influence human perception, including perceived biodiversity, preference, and restorative effects, within environments that maintain a consistent level of ecological biodiversity. This study constructed 16 hypothetical environments by combining three visual factors (species evenness, vegetation height, and plant color) with one auditory factor (presence or absence of natural sound), holding actual biodiversity constant. By comparing results from ANOVA and mixed-effect modeling, our analysis revealed important contrasts between the direct and indirect effects of visual and auditory features on perceived biodiversity and restoration. Plant height and natural sound consistently demonstrated direct positive effects on restorative outcomes. In contrast, plant color and species evenness influenced restoration indirectly, mediated through perceived biodiversity. The mixed-effect model indicated a partial mediation pathway between landscape features and restorative effects-an effect not observed in the ANOVA analysis. Surprisingly, species evenness was not directly associated with restorative outcomes, but was indirectly linked via perceived biodiversity. Similarly, while color enhanced biodiversity perception, it did not directly improve mental restoration and, under some conditions, may even contribute to overstimulation. These findings suggest that the restorative benefits of nature arise not only from the ecological composition of landscapes but also from how biodiversity is perceived. Designers and planners should consider not only biodiversity itself, but also how it is presented and perceived through multisensory experiences.