Comparing associations among sound sources, human behaviors, and soundscapes on central business and commercial streets in Seoul, Korea

This study focuses on how urban functions influence the soundscape in streets by exploring associations among human behaviors, soundscape, acoustic indicators. On-site soundscape assessments were conducted in eight urban streets located in Seoul employing a soundwalk method. The eight streets were classified into two place functions: central business district (CBD) and commercial areas. Through the soundwalks, acoustic recordings and perceptual responses to soundscapes in the streets were collected. As a human behavioral indicator, crowd density was calculated in the streets. The results showed that place function plays a critical role in soundscape evaluation in urban streets. Pleasantness decreased with increasing Eventfulness on streets in CBD. In contrast, Pleasantness had a positive correlation with Eventfulness on commercial streets. This difference in the correlation could be attributed to the difference in the compositions of sound sources between central business and commercial areas. Traffic noise was the most dominant sound source in CBD, which increased Eventfulness and decreased Pleasantness of the soundscape in the streets. Meanwhile, sounds from human activities contributed to an increase in both Pleasantness and Eventfulness in commercial streets. Predictive models of soundscape reflecting the contexts of CBD and commercial streets were developed using acoustic parameters and crowd density. In the context of CBD, acoustic parameters describing spectro-temporal characteristics of traffic noise were important indicators, whereas crowd density was found to be a critical indicator to predict soundscape in the commercial streets. These findings could help in better understanding the relationships between the soundscape and place functions in urban streets. •Traffic noise in streets in CBD decreased Pleasantness and increased Eventfulness.•Human-related sounds in commercial streets increased both Pleasantness and Eventfulness.•Spectro-temporal indicators were important to predict soundscapes in streets in CBD.•Crowd density was a critical predictor for soundscapes in commercial streets.