COVID-19 Pandemic Lowers Noise Pollution at Four Urban Locations

Noise pollution in cities has major negative effects on human health and wildlife. Changes in travel and other aspects of human activity during the COVID-19 pandemic provided an opportunity to investigate how urban noise levels could potentially be reduced. Using iPhones, we collected sound-level data before, during, and after the pandemic lockdown in the fall of 2020, when most people were required to remain at home. We made these measurements at four iconic sites in Boston (USA): the Boston University campus (which sits between two highways), the Fenway/Longwood area (including an urban park and several hospitals), Harvard Square (home of Harvard University), and East Boston (residential area near Logan Airport). Across all four sites, sound levels averaged 6.4 dB lower during the pandemic lockdown than after the lockdown, with fewer high noise measurements during the pandemic lockdown. Sound maps highlight noisy locations such as traffic intersections and quiet locations such as parks. We also found that battery-powered landscaping equipment was 10 dB quieter than equivalent gas-powered equipment. This project demonstrates that changes in human activity can reduce noise pollution and that smartphone technology can locate sources of high sound levels potentially harmful to human and wildlife health. Specific actions to reduce noise pollution at urban sites include increased planting of trees and shrubs, building sound barriers, changing traffic patterns, dispersing airplane flight paths, and switching to battery-powered equipment.