When I was a teenager, I knew that wearing sunscreen could help stave off skin cancer, that I shouldn’t smoke if I wanted to avoid lung cancer, and that condoms can prevent many sexually transmitted diseases.
No one warned me, however, that loud sounds — one screeching singer at a concert, or a construction drill — could permanently wreck my hearing. I also didn’t notice how ubiquitous the deafening din in our environment is.
Lately, though, I’ve been using decibel readers to track noise levels — in loud restaurants, on the street, in exercise classes and clothing stores — as part of a reporting project on noise. And I’ve found sound levels above 85 decibels, which are harmful to the ears, many places I go. Check out this decibel reading from a recent metro ride in Washington, DC:
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The same week, I went to a spinning class that registered volumes above 100 decibels. That’s enough to damage your hearing in 15 minutes.
It’s no wonder the World Health Organization has called environmental noise an “underestimated threat.” In the US, one in four adults in the US show signs of noise-induced hearing loss, and hearing loss (from all causes) is now the third most common chronic health condition in the US, just after diabetes and cancer.
This is frustrating because hearing loss is both irreparable and preventable. If we were more aware of the harms of blasting loud music, we would reduce noise pollution from the source. And if we knew to protect our ears from noise, we would reduce our risk of losing our hearing — the same way we know sunscreen protects us against skin cancer and condoms reduce our risk of STDs.
To better understand the impact of the din most of us now have to contend with, I dove into how noise-induced hearing loss works — and how it damages our health and well-being. Here’s what you need to know. The most frustrating thing about this status quo is that noise-induced hearing loss is both irreparable and entirely preventable.
Noise degrades hearing by damaging little hair cells in the ears
Let’s start at the beginning: How does all the noise erode our hearing in the first place? To grasp that, we need to walk through the fascinating machinery of the ear.
We’re born with about 16,000 little hair cells in our ears that act as sound detectors. When sound waves pass into our ears, the hair cells send a signal to the brain, and then our brain decodes the sound, whether it comes from a barking dog or a truck that’s passing by.
But “the brain’s interpretation is only as good as the signal it receives from the ear,” said Ellen Pfeffer Lafargue, an audiologist with the Center for Hearing and Communication in New York. “When the [hair cells in the] ear have been damaged, the sound that the brain gets is distorted or the ear can’t detect sound.”
Lafargue often uses the analogy of a grassy meadow to help her patients understand how noise degrades hearing. “Imagine a field, walking through the grass. When you walk through one time and look back, you can’t tell anybody walked on the grass.” The blades recover and bounce up again. But “if you’ve walked through it enough times, it becomes a permanent path.”
The same thing happens with the ears’ hair cells. Like grass responding to a person’s feet, the hair cells bend when they’re exposed to loud sounds. They can bounce back during a recovery period — but when loud sounds have passed through the ears enough times, or at a high enough intensity, the hair cells get permanently destroyed. Along with them goes our ability to detect sound and send noise signals to the brain.
One symptom of noise-induced hearing loss is tinnitus, or ringing in your ears. The condition can be extremely bothersome — and while there are treatments, there’s currently no cure. (You can listen to sample tinnitus sounds here.)
Even a single loud pop can do permanent damage to your hearing
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Sound is made by waves of air pressure, and decibels are the unit by which sound intensity is measured. They fall on a logarithmic, or nonlinear, scale, meaning the marks on the scale are based on orders of magnitude. So a noise level of 95 decibels is much louder than even 90 decibels, and so on.
The official government stance on safe noise levels comes from the National Institute for Occupational Safety and Health, which sets the standard for noise at work. It recommends limits of 85 decibels — a bit more than the loudness of a freight train 100 feet away — for eight hours a day, and that people exposed to anything louder use hearing protection. That’s because chronic noise exposures above this threshold have been shown to cause hearing loss over time.
But 85 decibels is not necessarily where hearing loss begins. Back in 1974, the Environmental Protection Agency suggested keeping noise levels around 70 decibels to optimally prevent noise-induced hearing loss. And the National Institutes of Health today suggests that sounds above 75 decibels can harm a person’s ability to hear.
What’s more, while being around loud sounds every day can certainly diminish your hearing over time, you don’t need sustained exposure to get permanent damage. A single pop of thundering noise — like a gunshot or an explosion greater than 120 decibels — is enough to do permanent damage. So exposure to sounds at that level takes even less time to diminish hearing.
And what about listening to music or podcasts all the time on earbuds, the ubiquitous symbol of millennials? The only thing that’s harmful about earbuds when it comes to hearing loss is the sound levels at which we use them. Cranked to their top volume, smartphones can carry sounds above 100 decibels, which even for 15 minutes can damage your hearing, the WHO has warned. (You may want to consider setting a maximum volume on your iPhone.) So using earbuds in and of themselves isn’t necessarily harmful, unless you’re turning up the volume all the time.
Aging makes hearing loss worse
Along with noise exposure, age is a major predictor of a person’s ability to hear. Our hearing declines with every passing decade. Just look at the steep increase in hearing loss in this chart from the Centers for Disease Control and Prevention:
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The prevalence of hearing loss increases from 7 percent among adults ages 20 to 29 to 68 percent among those 60 to 69, according to the CDC. And with untreated hearing loss, the agency warns, can come declines in “social, psychological, and cognitive functioning.” (Researchers have also long known that exposure to noise is associated with harmful sleep disturbances, endocrine effects, and an increased risk of diabetes and heart disease.)
But it’s difficult to disentangle the causes of age-related hearing loss, or “presbycusis,” from the causes of noise-induced hearing loss. That’s because presbycusis is most commonly caused by gradual changes in the inner ear, including the wear and tear to the hair cells brought on by noise.
There is some good news on this front, however: Researchers recently looked at whether the aging of the population was associated with an uptick in hearing loss cases. And they determined that among adults ages 20 to 69, the prevalence of hearing loss actually dropped between 1999 and 2004, from 16 percent to 14 percent. They postulated a few reasons:
Explanations for this trend are speculative, but could include reduction in exposure to occupational noise (fewer manufacturing jobs, more use of hearing protection devices), less smoking, and better management of other cardiovascular risk factors, such as hypertension and diabetes. Less plausible explanations, especially for beneficial changes in the most recent decade, might include fewer ear infections that are managed better as well as improved diet.
So even if many domains of the urban environment seem to be getting louder, our ears may be protected by these other means. The progress is not evenly spread throughout society. Noise pollution tends to be worse in communities of color — perhaps another driver of the black-white health gap in America.
The government isn’t doing much to fight noise. Here’s what you can do.
Researchers who study noise point out that the Industrial Revolution and urbanization ramped up the decibel levels in many of our communities. With these societal shifts came increases in population density (more people packed together means more noise), changes in transportation (goodbye, horse and buggy; hello, cars, trucks, traffic, and motorcycles), and — for a time, at least — more workers whose jobs involve really loud machines (though this may be turning around now).
In the early 1970s, the US government acknowledged the noise problem. President Richard Nixon passed the Noise Control Act in 1972, which recognized Americans’ right to a quiet environment. To enforce the act, Nixon also set up the Office of Noise Abatement and Control at the EPA. The office developed programs to prevent noise-induced hearing loss and educate people about the health effects of noise.
In 1981, President Ronald Regan came along and essentially shut down the effort, transferring noise control policy to state and local governments. “[He] said, ‘Let the cities and states handle noise,’” Arline Bronzaft, one of the country’s leading noise experts, told Vox. The trouble is, she added, many local governments had looked to the federal government for funding and support.
But since then, there’s been little attention paid to noise on the federal front. “The US was at the forefront in the ’70s, and today, in 2018, we have failed to fulfill the obligations under the Noise Control Act,” said Bronzaft. “It’s very sad.”
Most of the movement against noise has bubbled up from citizens’ groups and cities. In New York, for example, Bronzaft helped introduce a curriculum for schoolchildren to learn about the impact of noise and how to protect their ears early on in life. (The city updated its noise code in 2007, but noise is ever-present: Open data on noise complaints suggests loud music, construction, and loud talking are among people’s chief concerns.) Farther afield, in the UK, concerned citizens have helped organize a coalition to push back against Heathrow Airport’s third runway expansion, raising awareness about the health impact of the noise it would bring.
Still, it’s not hard to find restaurants, bars, concert halls, and construction sites with deafening noise levels and to see that many workers are going around unprotected.
In the absence of more robust public health campaigns and federal government intervention, preventing noise-induced hearing loss is mostly left up to individuals. The CDC has a good primer on the various things you can do to prevent hearing loss, such as wearing earmuffs while mowing your lawn, noise-canceling headphones in airplanes, and earplugs at concerts. These hearing protectors should be part of the same regular public health arsenal as sunscreen and condoms, and we should trot them out in any place we frequent that’s loud. (Even the gym!)
I’ll add that downloading a decibel meter, like SoundPrint, has helped me navigate my noisy cityscape. The readings I get make me more aware of the relative loudness of sounds around me and help me find quieter spots to eat dinner or have a drink.
There are also simple things designers and urban planners can do to improve noise control, argues Kate Wagner at the Atlantic:
... [They] can be as simple as taking a single lane away from cars and giving it to bicycles, people, or green space. Improving, expanding, and properly funding public transit removes cars from the road, both reducing the sound they produce and replacing it with quieter options like trams and high-speed light-rail. In architecture, acoustics should play a greater role in all structures, from mundane apartment buildings to the grandest art museums.
Finally, to avoid noise-induced hearing loss, as with many aspects of health, a little common sense can go a long way. As Nancy Nadler, the deputy executive director at the Center for Hearing and Communication, told me, “People need to use common sense. If it sounds too loud, it probably is. You need to understand once you damage your hearing from noise, you can’t do anything to get your hearing back.”
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