Effects of the Combination of Audio and Visual Factors on Mental Restoration in a Large-Scale Urban Greenway: Perspectives from Wuhan, China

The natural environment has been widely recognized as an important way of alleviating mental disorders. While a growing number of studies have discussed the restorative effect of the natural environment, the role of sounds in the natural environment (i.e., soundscape) on promoting mental restoration is under limited exploration. Therefore, we examined the restorative effect of visual stimuli and the combination of audio and visual factors in the natural environment. A total of 149 college students were divided into five groups, and exposed to different combinations of photos and sounds (with ‘silence’ as a control group) collected along the East Lake Greenway—the longest urban greenway in China. Structural equation modeling (SEM) was used to examine the correlation between characteristics of the natural environment and volunteers’ mental restoration, with place attachment as a mediator. Results showed that: (1) sound can alter the effect of visual factors on mental restoration; (2) birdsong can significantly enhance the restorative benefit of urban greenways; (3) an environment that is covered in greenery and consists of water sounds will contribute to a higher level of mental restoration; (4) human noise will have a negative impact on mental restoration; (5) place attachment is a mediator between the natural environment and mental restoration. This study highlights the effectiveness of sounds in the natural environment in promoting mental restoration, and broadens our understanding of the link between the natural environment and mental health. We propose that not only visual factors, but also audio-visual combinations, should be considered when creating restorative environments.