COVID-19 lockdowns have silenced urban noise. Now it's coming back

As the coronavirus kept more people indoors, many felt an important part of their lives had vanished: noise.

For city dwellers around the world, social distancing and stay-at-home orders quelled the daily bustle that usually surrounds them – and amplified (sometimes unpleasantly) the sounds of nature. Decibel levels in New Delhi diminished, people in Paris suddenly discovered the sound of local river birds, London tourist spots like the Millennium Bridge were virtually silenced, and subway musicians in New York City were replaced by a Spotify playlist.

The stillness has not always been welcomed. For many people, the new absence of sound was an eerie reminder of the unsettling circumstances, signifying troubled economies and the difficulty faced by many people trying to earn a living. It also amplified the blare of sirens as ambulance crews scrambled to save the lives of the infected. A growing urban din may therefore bring a comforting return to normalcy.

In fact, some studies suggest humans need noise. A moderate amount of ambient noise has been found to enhance performance when it comes to creative tasks, and loudness can sometimes be desirable.

However, noise pollution can also seriously undermine health and quality of life generally. While the sound of normal conversation registers at about 60 decibels, heavy traffic can approach 90 decibels. Exposure to anything above 85 decibels for more than eight hours is considered hazardous.

Many places have made efforts to curb harmful noise, whether it’s Minneapolis mandating that nightclubs make earplugs free to patrons, New Delhi arming police officers with decibel meters, or New York City making the unnecessary honking of a car horn punishable with a $350 fine. Such concerns largely became moot after New York implemented a statewide stay-at home order on 20 March. The resulting decline in mobility in New York City can be seen below, in part of a visualization created by the World Economic Forum where bright white represents normal daily mobility – and turns darker as it declines, eventually hitting a black indicating 0% of normal.

Many people will welcome the return of urban clamour, even if it might accompany a surge of new COVID-19 cases in some places. In the future, more carefully managing these noise levels may be one way cities build back better after the pandemic recedes.

For more context, here are links to further reading from the World Economic Forum’s Strategic Intelligence platform:

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