Sound and noise in urban parks

Abstract

The main goal of this work is to study the soundscape of city gardens and urban parks using a sample of ten sites in Oporto, Portugal to analyze their soundscape 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 dB(A) (with exterior noise levels up to 67 dB(A)). The difference between exterior and interior LAeq was between 3 and 19 dB. The gardens with lower noise levels are the largest and out of downtown. An acoustic classification for gardens/urban parks is proposed regarding their noise isolation capacity and their acoustic ambience. Measurements also done in 1990 allow for the comparison of the acoustic evolution in the last 21 years. The socio-acoustic survey concludes that Oportos 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 sound sources, classifying those spaces as pleasant and quiet, even when noise is over acceptable limits.