Characteristics and evaluation of urban soundscapes worthy of preservation

Improvement of the sound environment is essential for improving the overall quality of the urban environment and for reflecting the characteristics of a city. Unfortunately, some soundscapes in cities are gradually being destroyed by the rapid development. Therefore, it would appear that the preservation of soundscapes is as necessary and crucial as noise control in cities. In this paper two field studies were carried out at two stages to explore the types and characteristics of urban soundscapes that should be preserved, based on the example of Tianjin, China. At stage one, 2504 respondents participated in social surveys to recommend the soundscapes worthy of preservation in the city. At stage two, a group soundscape walk with twenty-three participants was carried out to explore the characteristics of soundscapes worthy of preservation suggested by the respondents at the first stage. The following results were obtained: (1) regarding the attitude towards the urgency of soundscape preservation, 79% of the respondents thought it was urgent or very urgent, with an average score of 4.04 (five-point numeric scale was used and five meant very urgent). (2) The majority of soundscapes worthy of preservation were located in urban parks and historic districts with respective proportions of 66% and 20%. The top three sound source categories of these soundscapes were social/communal sounds (talking, bells, laughter, and sounds from human activities), animal sounds (birdsong and sounds from non-domesticated animals) and water sounds. (3) Relaxation, vibrancy, representativeness, strength, and richness were principal characteristics of the soundscapes worthy of preservation. (4) Based on their characteristics, these soundscapes were classified into five clusters using hierarchical cluster analysis (HCA). They were clusters of relaxing nature soundscape, vibrant nature soundscape, vibrant human activity soundscape, culture-related soundscape and traditional soundscape. The dominant characteristic of each cluster was driven by its sound mark rather than the dominant sound.