Towards an environmental sound map at Parco Nord of Milan, Italy

Green areas suffer the growing influence of urbanization and may benefit from the use of passive acoustic monitoring (PAM) which can provide biodiversity estimation and conservation especially in fragile environments such as urban parks and protected areas. A network of low-cost sensors has been distributed over an area of approximately 20 hectares at the Parco Nord of Milan, Italy, to highlight areas with different acoustic characteristics. The audio files analysed in this study were recorded at 16 sites on four sessions between May 25th and May 29th 2015 from 06:30 a.m. to 10:00 a.m.. Seven eco-acoustic indices have been computed and analysed. A map of eco-acoustic indices has been built and validated by comparing the results with an aural survey aimed at determining the sound components at each of the sixteen sites (biophonies, technophonies and geophonies). This approach may represent a useful tool for an integrated approach aimed at conservation planning and development decisions.