The “sound of silence” in Granada during the COVID-19 lockdown

Abstract

Exceptional circumstances in the city of Granada due to the COVID-19 lockdown have provided the opportunity to characterise the impact of humans on its urban acoustic climate. Traditional environmental noise management and urban sound planning usually take into account noise sources in the city, such as industrial activities or road traffic noise, in model estimations, as well as in empirical research. But trying to isolate human impact by itself, human activity including social activity, walking, talking or just going around the city, has always been a difficult or even impossible task. The COVID-19 lockdown measures have provided the opportunity to study urban climate as never before, affected just by natural or animal noise sources. Previous soundscape research at some iconic sites in the city of Granada carried out in 2019 before the lockdown and a special measuring campaign carried out at the same locations during the lockdown in 2020 offered valuable information on sound levels and local characteristics in order to carry out this comparison. Results show a great change in environmental noise levels that is interesting not only because of its magnitude, but also for its implications, especially at those sites where social human activity was an identifying characteristic. Natural or animal sounds became surprisingly evident at some study sites, especially where road traffic noise dramatically decreased, leading to significantly lower background noise levels. Important spectral changes are observed before and during the lockdown, suggesting a shift from anthropic to animal sources in the acoustic environment.

Quieted City Sounds during the COVID-19 Pandemic in Montreal

“…The presence of a water feature (i.e., a nearby river) maintained one of the four sites at a higher background level, based on L 90 measurements. They found also a dramatic decline in low frequency sound and a 60-80% reduction in modeled loudness at these four tourist sites [18].…”

“…RQ2: In the absence of festivals, the sound levels could be characterized as being 'as high as' 15 dBA lower than pre-pandemic. The only study showing comparable changes came from the touristic areas of Granada [18], which had between a 13 and 30 dBA drop. The differences, however, were that in Montreal, the microphones were specifically monitoring the sound levels of loud festivals-in the absence of these festival activities, it was still a loud central urban area with human activities, construction, and other mechanical equipment.…”

Impact of the COVID-19 Lockdown Measures on Noise Levels in Urban Areas—A Pre/during Comparison of Long-Term Sound Pressure Measurements in the Ruhr Area, Germany

“…On the other hand, to date there is only one study reporting distinctly higher noise reductions ranging between 20 and 30 dB(A) at four tourist locations in Granada, Spain [ 28 ]. However, the reported reductions are based on the comparison of two recordings per location, which were also carried out at different times of day.…”

The Soundscape of the COVID-19 Lockdown: Barcelona Noise Monitoring Network Case Study

“…During the 2020 lockdown period in the city of Granada, Spain, a research work registered the sound pressure levels (SPL) at four typical tourist points with the aim to check the affect on soundscape due to the lack of human activity [ 6 ]. They compared 6 min of data gathered during lockdown with 6 min of data recorded 1 year before at the same points, with the intent to identify changes or shifts of temporal or spectral patterns.…”