Effect of soundscape dimensions on acoustic comfort in urban open public spaces

Soundscapes in public squares play important roles in urban open spaces. This study aimed to discover the effect of four soundscape dimensions, namely relaxation, communication, spatiality and dynamics, on acoustic comfort in urban open public spaces. A typical city square in China was selected as a case site. Sound environment measurements and questionnaire surveys were carried out for 8 survey positions. The results showed that the perceived dominance of sound sources had a significant effect on relaxation, communication, spatiality and dynamics. Relaxation was greater when the natural sound was perceived dominantly, while it was lower when mechanical sounds or anthropogenic sounds were perceived dominantly. Acoustic comfort had a significant correlation with the soundscape dimensions and LAeq, with spearman's correlation coefficients of 0.495 (relaxation), 0.210 (sound pressure level) and 0.288 (spatiality). In terms of the differences in perceived sound types, acoustic comfort was positively correlated with relaxation when natural sound or anthropogenic sound was perceived dominantly. As spatiality increased, acoustic comfort first decreased and later increased when relaxation was higher, while there were positive correlations between acoustic comfort and relaxation under the other situations. Moreover, when spatiality or communication was higher, there were significant correlations between acoustic comfort and dynamics. According to these results, acoustic comfort can be increased as soundscape dimensions change in an urban open public space.