Traffic Sounds in Office Spaces: PLS-SEM Study on Audio-Visual Perception with Open or Closed Windows and Biophilic Design.

Herein, we investigated the audio–visual perception of indoor greenery and intruding traffic sounds through open or closed windows in a shared office context that accommodates two people. A set of 32 audio–visual stimuli was used, featuring combinations of greenery dosages (0%, 7%, 10% and 13%) and traffic sound levels (50 dBA, 55 dBA, 60 dBA and 65 dBA) , for both open and closed windows. These stimuli were presented to 42 participants in an indoor office environment using two-dimensional screens and over-ear headphones. We employed a partial least squares structural equation model to integrate greenery dosages, traffic sound levels and perceptual attributes such as pleasantness, eventfulness, appropriateness, preference and visual aesthetics. The findings demonstrate the impact of traffic sound levels on visual perception, highlighting a bidirectional interaction between auditory and visual perceptions. Indoor greenery indirectly enhances the pleasantness of the auditory environment, supporting the implementation of biophilic design in office spaces that are visually appealing and acoustically pleasant. Furthermore, the study contributes to discussions on adaptive acoustic comfort in naturally ventilated spaces, providing evidence of how visual perception impacts the acoustic environment. While the research results highlight the positive impact of open windows on the appropriateness ratings of traffic sounds, it is important to consider the limitation of assessing outdoor-recorded traffic sounds at high sound pressure levels (50–65 dBA) without the filtering effect of the facade. This limitation reduces the realism and ecological validity of the experiment, which should be considered when interpreting these results.