Influence of traffic speed and acoustic environment on perception and perceived workload in virtual reality

Road traffic substantially shapes urban acoustic environments and their perception. While debates on urban speed limits mainly focus on safety and emissions, less is known about their perceptual effects on urban soundscapes. To evaluate these effects, a laboratory study in virtual reality was conducted in which 34 participants completed rating and performance tasks within a simulated urban green space. Traffic noise under two speed limit conditions (30 km/h and 50 km/h) was combined with three types of non-traffic acoustic environments (anthrophonic, geophonic, and biophonic). In a first experiment, perceived affective quality ratings were collected to determine the soundscape dimensions pleasantness and eventfulness. In a second experiment, participants completed a 2-back task under both speed limit conditions, after which subjective workload was assessed using the NASA Task Load Index. Both speed limit and environment type significantly affected pleasantness and eventfulness, with speed limit exerting a stronger influence on pleasantness and environment type a stronger influence on eventfulness. Although perceived workload was slightly higher in the 50 km/h condition, the effect was not significant. These findings highlight the importance of perceptual factors in shaping urban acoustic well-being.