People's exposure to environmental noise dropped nearly by half during the early months of the Covid-19 pandemic, say researchers, adding that lockdowns and stay-at-home orders led to a dramatic reduction in noise exposure.
For the study, published in the journal 'Environmental Research Letters', the research team looked at noise exposure data from volunteer Apple Watch users in Florida, New York, California and Texas in the US.
The analysis, one of the largest till date, included more than half a million daily noise levels measured before and during the pandemic.
The findings showed that daily average sound levels dropped nearly three decibels during the time that local governments made announcements about social distancing and issued stay-at-home orders in March and April compared to January and February.
"That is a huge reduction in terms of exposure and it could have a great effect on people's overall health outcomes over time," said study author Rick Neitzel, University of Michigan, US.
"The analysis demonstrates the utility of everyday use of digital devices in evaluating daily behaviours and exposures," Neitzel added.
The four states reviewed in this analysis had differing Covid-19 responses in terms of stay-at-home orders which showed through the data.
"California and New York both had really drastic reductions in sound that happened very quickly whereas Florida and Texas had somewhat less of a reduction," Neitzel said.
Initially, the largest drop in environmental sound exposure was seen during the weekends, where nearly 100 per cent of participants reduced their time spent above the 75-dB threshold (a sound level roughly as loud as an alarm clock) between Friday and Sunday.
"But after the lockdowns when people stopped physically going to work, the pattern became more opaque," Neitzel added.
"People's daily routines were disrupted and we no longer saw a large distinction in exposures between the traditional five working days versus the weekend," Neitzel said.
These data points allow researchers to begin describing what personal sound exposures are like for Americans who live in a particular state or are of a specific age or who have/don't have hearing loss.
"This is data that never existed or was even possible before," the study authors wrote.