Characteristics and perception evaluation of the soundscapes of public spaces on both sides of the elevated road: A case study in Suzhou, China

Abstract

• Vehicle driving sounds have no correlation with mechanical sound perception and soundscape satisfaction in high traffic. • The insertion of fountains and elimination of horn and siren sounds are preferred. • Soundscapes in street parks are more positive than those in commercial plazas and pedestrian areas. • Quietness, pleasantness, eventfulness, and distinctiveness influence the soundscape evaluation. • Spatial characteristics of public spaces can be used to predict the soundscape evaluation. Elevated roads bring considerable noise pollution and have huge negative effects on the quality of roadside public spaces. There is growing evidence that noise pollution should be addressed within a broader soundscape methodology rather than merely noise control. In this study, objective sound level measurements and subjective questionnaires were conducted in the 20 study sections of public spaces on both sides of the East Ring Elevated Road in Suzhou, China. This study aims to explore the soundscape characteristics in such spaces and identify the influencing factors of soundscape evaluation. The results show that the soundscape compositions (sound level and sources) of pedestrian areas, street parks, and commercial plazas are significantly different. In addition, the dominant sounds, vehicle driving sounds (34.5%), have no correlation with soundscape satisfaction, while fountain ( p <0.01), horn ( p <0.01) and siren sounds do ( p <0.01). Adding natural sounds ( p <0.05), reducing mechanical sounds ( p <0.01), and optimizing landscape ( p <0.01) can improve soundscape quality. Moreover, respondent characteristics are correlated with soundscape evaluation. Furthermore, the dimensions of soundscape perception could be classified into four factors, quietness, pleasantness, eventfulness, and distinctiveness, for a complete understanding of soundscapes. A model of spatial characteristics (natural-artificial, wide-narrow) to predict soundscapes evaluation is also constructed.