Spatial evaluation of environmental noise with the use of participatory sensing system in Singapore

Abstract

Existing studies in Singapore on environmental noise are scarce and limited in scale due to the need for expensive equipment and sophisticated modelling expertise. This study presents the approach of using participatory sensing and mobile phones to monitor environmental sound levels around Singapore. iPhones running the AmbiCiti application was adopted to sample equivalent continuous 30-second average outdoor sound levels (LAeq,30sec). The aggregated mean of each region was evaluated and the spatial distribution of environmental noise was analysed using noise maps generated from the measurement data. A total of 18,768 LAeq,30sec measurements were collected over ten weeks. About 93.6% of the daytime measurements (07:00 - 19:00) exceeded the WHO recommended level of 55 dBA to minimise negative non-auditory health effects due to noise. The results of this study suggest that the population of Singapore is potentially at risk of adverse non-auditory health effects and, to a lesser extent, hearing loss due to community noise levels. However, the measurements exceeding 70 dBA were frequent enough to warrant concern about contributions to the cumulative lifetime sound exposure contributing to hearing loss. The work also demonstrates that sound maps of an area can be efficiently generated using calibrated applications running on smart phones.