Effects of audio-visual interaction on soundscape perception in urban courtyards

Urban courtyards are important components of the built environment, influencing human perception and emotional responses. Previous VR-based research has shown that incorporating natural elements such as trees, vegetation, and birdsong can enhance pleasantness; however, comprehensive analysis using standardized soundscape assessments has been limited. This study aims to extend previous work by applying ISO-based soundscape evaluation to examine how different courtyard design features affect perceivedpleasantness (P) and eventfulness (E). A VR experiment was conducted with three presentation modes: visual only, audio only, and audio-visual. Five types of courtyard design features were modeled. Participants evaluated each scene using the ISO-recommended eight soundscape adjectives together with an overall soundscape quality scale, provided in Japanese, and pleasantness (P) and eventfulness (E) were calculated. Preliminary findings indicate that, regardless of courtyard size, incorporating natural design features such as trees, vegetation, and water is associated with higher pleasantness (P) scores and more favorable overall sound environment evaluations. For eventfulness (E), no significant differences were observed in small courtyards, while in large courtyards combinations that include trees and birdsong showed higher eventfulness values.