A dataset of acoustic measurements from soundscapes collected worldwide during the COVID-19 pandemic

Abstract

Political responses to the COVID-19 pandemic led to changes in city soundscapes around the globe. From March to October 2020, a consortium of 261 contributors from 35 countries brought together by the Silent Cities project built a unique soundscape recordings collection to report on local acoustic changes in urban areas. We present this collection here, along with metadata including observational descriptions of the local areas from the contributors, open-source environmental data, open-source confinement levels and calculation of acoustic descriptors. We performed a technical validation of the dataset using statistical models run on a subset of manually annotated soundscapes. Results confirmed the large-scale usability of ecoacoustic indices and automatic sound event recognition in the Silent Cities soundscape collection. We expect this dataset to be useful for research in the multidisciplinary field of environmental sciences.

Fig. 1

Panel a. Global and European mapping of recording sites. Colors refer to climates. Panel b. Number of recording sites per country. Colors refer to continents. Panel c. Number of recordings by confinement level and climate. Panel d: temporal distribution of global sampling effort, in number of recordings.

Fig. 2

Panel a. Top left: Professional fields of the 261 participants. Middle: Distribution of type of devices for the 317 recording sites. Bottom left: type of protocol implemented. Right: Photos of the two main recording devices used: Open Acoustic Devices AudioMoth (top) and Wildlife Acoustics SM4 (bottom). Panel b. Association between the measured acoustic indices and tagging types and the presence of geophonical (Geo), biophonical (Bio) and anthropophonical (Ant) events detected manually by the contributors. Model estimates and associated 95% confidence intervals are represented with points and bars, respectively. Positive and negative estimates with confidence intervals not overlapping zero indicate positive and negative associations, respectively. Panel c. Radial barplots depicting the mean anthropophony and biophony level values per site, combining all protocols, recorded hourly throughout each period of COVID-19 containment levels. Panel d. Model predictions and associated 95% confidence intervals for NDSI, biophony (birds) and anthropophony (engine noise) levels at 8:00 a.m. during the COVID-19 confinement measures, following the expert protocol only. ***p < 0.001, **p < 0.010, *p < 0.050, ns: p > 0.050.