• As lockdowns ease, the return of noise will be comforting to many people, some studies even suggest a moderate amount of ambient noise enhances performance.
  • But noise pollution can seriously undermine health and quality of life generally. There is an opportunity to better manage noise pollution to help cities thrive post-COVID-19.

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.

Image: World Economic Forum

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.

Daily mobility in New York City (US date format).
Daily mobility in New York City (US date format).
Image: World Economic Forum

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:

  • Some people in New York City missed the urban din so much, the New York Public Library released an album of sounds including barking dogs and a subway station at rush hour, according to this report. (New Yorker)
  • As urban areas grew quiet the internet was populated with images of newly emboldened wildlife, including goats roaming city streets. But lockdowns haven’t necessarily been good news for animals that rely on humans for survival, according to this lecturer in human geography. (The Conversation)
  • Some cities in the United Kingdom might enjoy a prolonged break from traffic noise, as they consider turning parts of main roads into cycling paths and pedestrianizing other areas after the pandemic recedes, according to this report. (CityMetric)
  • In many cities, much of the noise decline has been due to fewer planes flying overhead – as no industry in the world has been hit harder by the pandemic than aviation, according to participants in this discussion. (Harvard Business Review)
  • In cities like Nairobi, some of the quiet of lockdown resulted from reduced ridership on informal transit services. According to this report, it’s now unclear whether many of these crucial, privately-owned businesses can survive. (Wired)
  • Much of the increased bustle on city streets will be a result of restarted religious services. In Iran, according to this report, holy shrines are being reopened even as the death toll in that country tops 7,500. (Al-Monitor)
  • One downside of the lockdown-induced silence, according to this opinion piece: it amplified the noise of self-proclaimed experts spreading disinformation. (The National)

On the Strategic Intelligence platform, you can find visualizations and feeds of expert analysis related to COVID-19, Cities and Urbanization and hundreds of additional topics. You’ll need to register to view.

Image: World Economic Forum