Which factors enhance the perceived restorativeness of streetscapes: sound, vision, or their combined effects? Insights from four street types in Nanjing, China

Streetscapes play a critical role in restorative landscapes, offering opportunities for promoting public well-being. Previous studies have predominantly examined the influence of visual and auditory stimuli on perceived restorativeness independently. There is a limited understanding of their interactive effects. In this research, 360 participants completed a series of experiments considering four distinct street types, including visual comfort assessment, acoustic environment assessment, and perceived restorativeness. They were assigned to a control group and one of three experimental groups, each receiving specific enhancement: visual stimuli, auditory stimuli, or a combination of audiovisual stimuli. The findings revealed that the experimental groups reported a greater sense of restorativeness compared to the control group. Notably, auditory stimuli demonstrated a more pronounced restorative effect than visual stimuli, while limited differences were found between auditory and audiovisual stimuli. The differences in experimental outcomes among the four street types are compared and discussed, highlighting context-specific guidelines for enhancing streetscape restorativeness. The research findings highlight enhancing the masking effect of soundscape in street environmental design. The study adds a novel multi-sensory approach to the current body of research on restorative landscapes, providing significant insights for the planning and design of streetscapes.