Soundscape of an Urban Green Area of Milan

Over the last century, anthropogenic activities have caused significant changes in soundscapes. These alterations are mainly caused by growing noise related to the expansion of cities and their connections (e.g. roads). It is urgent to understand the distribution of noise pollution and its effect on biodiversity, especially in large cities, aiming to propose legal regulations and mitigation actions to reduce its impact. In this study, we assessed the soundscape of the pocket- park Vivaio-Bicocca of Milan (Italy), in a highly anthropized urban context, as a starting point to understand the effect of noise pollution on the city wildlife. Audio recordings took place 24h a day from May 31st to June 14th 2022 (1 minute of recordings followed by 5-minutes pause) with autonomous recorders in three sites 45m apart, while noise level was measured using a Sound-Level-Meter. Soundscape analyses were performed calculating eco- acoustic indices (e.g. Acoustic Complexity Index, Acoustic Diversity Index, Normalized Difference Soundscape Index) in the R environment. As expected, the soundscape of the three sites resulted quite similar, composed of biophony and a high quantity of anthropophony. We hypothesize that the central site could be representative of the whole park and be used on its own for the soundscape characterization.