Sound and noise in urban parks

Abstract

The main goal of this work is to study the soundscape of urban gardens and parks using a sample of ten sites in Porto, Portugal to characterize their noise levels through the acoustic characterization of the park's exterior and interior noise levels (LAeq, LA10, LA50 and LA90) and by a socio-acoustic survey to the visitors to check their perception of acoustic quality. The measurements showed gardens/parks with interior noise levels from 47 to 61 dBA (with maximum exterior noise levels up to 67 dBA). The difference between exterior and interior LAeq was between 3 and 19 dBA. The gardens with lower noise levels are the larger and out of downtown. An “acoustic” classification for gardens/urban parks is proposed regarding their noise “isolation” capacity and acoustic ambience. Measurements done in 1990 allow for the comparison of the evolution in the last 21 years. The socio-acoustic survey concludes that Porto’s city parks are visited mostly by an elderly male population that regards these places as sites of gathering and to practice some physical activity rather than as an acoustic retreat. The population seems accustomed to the dominant noise, classifying these spaces as pleasant and quiet, even when noise is over acceptable limits.