WHO Wants to Hear the Sound of Silence

person walking through a foggy forest
The sights, sounds and smells of a forest are powerful balms for the human brain. (Photo: Dmytro Gilitukha/Shutterstock)

Turn down the volume and listen up!

The World Health Organization (WHO) has released a new set of guidelines about environmental noise.

"More than a nuisance, excessive noise is a health risk — contributing to cardiovascular diseases, for example. We need to act on the many sources of noise pollution — from motorized vehicles to loud nightclubs and concerts — to protect our health," Dr. Zsuzsanna Jakab, WHO regional director for Europe, said in a statement.

Quiet, please

Calling noise "one of the top environmental hazards to both physical and mental health" in Europe, WHO's report is the first on noise since 2009, and it makes recommendations about noises of all kinds, from traffic to concerts to wind turbines to ear buds. (Those last three noise sources weren't included in the 2009 report.)

Relying on the work of different teams of noise experts, WHO developed the guidelines by reviewing recent research on noise pollution. The teams mainly used studies conducted in Europe — and the guidelines were designed in part to be consistent with the European Union's Environmental Noise Directive — but they also considered studies done in America, Australia and Asia, making the recommendations of global significance.

For instance, the new guidelines suggest that road traffic noises should be below 53 decibels during the day, with 45 decibels the target at night. WHO says that 44 percent of EU residents are exposed to traffic noise above 55 decibels.

When it comes to noise from railways, airplanes and wind turbines, the report suggests an average level of 44 to 54 decibels, depending on the source. Nighttime air noise should be less than 40 decibels, lest it impact sleep.

A woman in a white sweater covers her ears with her hands as a bus drives behind her
Transportation sounds may just be background noise for some, but they can still affect your health. Fotos593/Shutterstock

While the recommendations regarding things like traffic and wind turbines is targeted at policymakers, the report's guidelines on leisure noise, meaning noises from concerts, nightclubs and the music we listen through to our earbuds and headphones, are something everyone can be more keenly aware of. Here, WHO recommends limiting all leisure noise exposure to a combined yearly amount of 70 decibels.

Based on their surveys, WHO estimates that almost half of those aged 12 to 35 years living in middle- and high-income countries listen to "unsafe levels of sound" through personal listening devices like smartphones and MP3 players. It further estimated that 1.1 billion young people worldwide could be at risk of hearing loss caused by dangerous listening habits.

Noise pollution is diverse, and its effects can vary depending on the loudness and consistency of the source.

"Exposure to environmental noise can result in hearing loss that, in the longer term, can cause social isolation and [have an] impact on health and well-being," Jonathan Gale, a professor of cell biology and director of the UCL Ear Institute told CNN via email. "Both the level and duration of the exposure are important factors.

"However we know much less about the effects of exposure to low levels of environmental noise over long periods," he added. "We think such noise is unlikely to affect our sensory hair cells [in our ears] but may well effect our brain processes and possibly our mental health."

Apart from hearing loss and impairment, the report highlights how noises can affect sleep, cardiovascular health, birth outcomes and overall well-being.