Health and Noise

Sounding off on noise

Jeanine Barone, writing for Principa-Scientific International, interviews Arline Bronzaft, PhD, asking Dr. Bronzaft about her lifetime of fighting noise. Dr. Bronzaft, an environmental psychologist, is a professor emerita of psychology at Lehman College, City University of New York, and an expert witness in court cases and government hearings on the impact of noise on mental and physical well-being.  She also is a founding member of The Quiet Coalition.

Barone wonders whether noise has to be loud to affect people, to which Dr. Bronzaft responds that noise doesn’t necessarily have to be loud to affect someone because “[n]oise is any unwanted, uncontrollable, or unpredictable sound.”  Dr. Bronzaft describes the negative effects of noise on health and quality of life, including its impact on children’s learning.

That noise is understood to be detrimental to children’s learning is due in large part to Dr. Bronzaft’s landmark study of an elementary school adjacent to an elevated train track in New York City. On one side of the building “the classrooms were exposed to passing train noise every 4.5 minutes,” while on the other side of the building “the classrooms were not intruded upon by passing train noise.”  Dr. Bronzaft’s study showed that “[b]y the sixth grade, the children exposed to noise were nearly a year behind in reading.”

But Dr. Bronzaft didn’t conclude her study and move on.  Rather, she brought the data to the transit authority and convinced them to employ noise suppression technology on the nearby tracks.  Some years later she did a follow-up study that found that the noise had decreased and “children on both sides of the school were reading at the same level.”

Click the link to learn more about Dr. Bronzaft’s work

Loud sound may pose more harm than previously thought

The Associated Press (AP) reports that “[s]cientists have been finding evidence that loud noise — from rock concerts, leaf blowers, power tools, and the like — damages our hearing in a previously unsuspected way.”  The damage “may not be immediately noticeable, and it does not show up in standard hearing tests,” the AP adds, but according to Harvard researcher M. Charles Liberman,” it can rob our ability to understand conversation in a noisy setting [and] may also help explain why people have more trouble doing that as they age.”  The condition is called “hidden hearing loss,” and Liberman adds that “[n]oise is more dangerous than we thought.”

The AP interviews Matt Garlock, a 29-year old systems engineer who is “a veteran of rock concerts.”  Garlock complained of not being able to hear friends in a crowded bar, but when he got his hearing checked his test results were normal. The AP writes that Liberman’s work “suggests that there’s another kind of damage that doesn’t kill off hair cells, but which leads to experiences like Garlock’s.”  Specifically, Liberman believes that loud noise damages the delicate connections between hair cells, called synapses.  He adds that animal studies show that “you could lose more than half of your synapses without any effect on how you score on an audiogram,” but if you lose enough synapses, it “erodes the message the nerves deliver to the brain, wiping out details that are crucial for sifting conversation out from background noise.”

The end result is that people like Garlock recognize that they have a problem but their hearing appears to be fine when they take conventional hearing tests. Fortunately, Liberman says that “[o]ne encouraging indication from the animal studies is that a drug might be able to spur nerves to regrow the lost synapses.”  [Note: This article notes that Liberman has a financial stake in a company that is trying to develop such treatments.]  But while treatment for hidden hearing loss may be available in the future, what can be done now?  Liberman states that his work “lends a new urgency to the standard advice about protecting the ears in loud places.”  As always, prevention is better than treatment.

 

Another Silent Spring

By Daniel Fink, MD, Chair, The Quiet Coalition

In 1962, Rachel Carson’s “Silent Spring” described the harmful effects of insecticides and herbicides on birds, beneficial insects, animals, and humans.  Her book helped start the environmental movement. For too many people, this will be another silent spring, caused not by a dearth of birds but because people can’t hear birds sing. They have hearing loss from another environmental pollutant, noise.

Carson described how nature’s balance controlled pest species naturally, and how these species became problems only when humans changed the environment. She noted the difference between apparent short-term safety of agrichemicals and longer-term danger. People could get sprayed with pesticides or even ingest them without apparent immediate harm, with cancer and birth defects coming later.

If Carson were alive today, she might write about noise pollution, which interferes with animal feeding, communication, mating behaviors, and navigation in forests, fields, and oceans, and causes hearing loss and other medical problems in humans.  In nature’s quiet, animals developed exquisite hearing to find food or avoid being eaten. An owl can find a mouse under a foot of snow, and zebras can hear lions approaching in the veldt.

Humans are also born with excellent hearing.  Brief exposure to loud noise usually doesn’t cause obvious auditory damage in humans, but longer or repeated exposure does. The relationship between noise and hearing loss was first noted in medieval times in bell ringers and miners, then in boilermakers during the industrial revolution.  Noise wasn’t a widespread problem, and except in large cities life was usually quiet.

Industrialization, mechanization, and urbanization made life noisier.  Noise was recognized as a public health hazard in the early days of interstate highways and jet travel, but was also considered an environmental pollutant. In 1972 Congress passed the Noise Pollution and Abatement Act, empowering the Environmental Protection Agency (EPA) to establish noise standards and require noise labeling for consumer and industrial products.

During the Reagan administration, however, Congress defunded EPA noise control activities. Little has been done since to control noise, and our country has gotten noticeably louder. Sound levels of 90-100 decibels or louder are reported in restaurants, clubs, retail stores, movie theaters, gyms, sports events, concerts, and parties, from sirens, vehicles, landscape maintenance equipment, and construction, and for those using personal music players.

The National Institutes of Health states that prolonged exposure to noise at or above 85 decibels can cause hearing loss. This is misleading, because no exposure time is given and hearing damage occurs at much lower levels. The 85-decibel standard is an occupational noise exposure standard, not a safe noise level for the public.. The EPA adjusted the occupational standard for additional noise exposure outside the workplace to calculate the noise level for preventing hearing loss to be a daily time-weighted average of only 70 decibels.

Hearing is the social sense, required for spoken communication. About 40 million American adults age 20-69 have noise induced hearing loss, half of them without noisy jobs. Why is this happening? They are exposed to loud everyday noise.  Cumulative noise exposure eventually causes hearing loss, affecting 25% of those in their 60s, half in their 70s, and 80% in their 80s, and is correlated with social isolation, depression, dementia, falls, and mortality. Due to denial, stigma, and cost only 20% of older Americans with hearing loss acquire hearing aids, after an average seven-year delay, and 40% of people with hearing aids don’t use them much, largely because hearing aids don’t help users understand speech well in noisy environments.

Preventing noise-induced hearing loss is simple: avoid loud noise. If it sounds too loud, it is too loud. Free or inexpensive smart phone sound meter apps make it easy to measure sound levels, but if one can’t converse without straining to speak or to be heard, ambient noise is above the auditory injury threshold of 75-78 decibels and auditory damage is occurring.

A quieter world is easily attainable. Whisper-quiet dishwashers, cars with quiet interiors and exhausts, the Airbus A380, and a few quiet restaurants and stores prove this.   Effective noise control technologies have long existed, including noise reduction via design and material specifications and sound insulating, isolating, reflecting, diffusing, or absorbing techniques.  Indoors, all that may be necessary is turning down the background music volume, which costs nothing.

In the 1950s and 1960s, half of all American men smoked and public spaces and workplaces were filled with tobacco smoke. When research showed that tobacco smoke caused cancer and heart disease, governments restricted smoking, leading eventually to today’s largely smoke-free society. Smokers can still smoke, but can’t expose others involuntarily to their smoke.

Noise causes hearing loss. Governments should set and enforce indoor and outdoor noise standards, to reduce each person’s daily noise dose. Adults have the right to make and listen to all the noise they want, but not where others can hear them. If we can breathe smoke-free air, we can make a quieter world, so future generations won’t have to endure another silent spring.

Dr. Fink is a leading noise activist based in the Los Angeles area.  He serves on the board of the American Tinnitus Association and is the interim chair of Quiet Communities’s Health Advisory Council and the founding chair of The Quiet Coalition, an organization of science, health, and legal professionals concerned about the impacts of noise on health, environment, learning, productivity, and quality of life in America.

Originally posted at The Quiet Coalition.

What’s the difference between noise and sound?

By Daniel Fink, MD

One of the heated discussions that sometimes occurs among those of us concerned about noise is the use of the terms “noise” and “sound.” Some people insist that we hear noise but measure sound. Others say the terms can be used interchangeably.

The word “noise” means “unwanted sound,” with an implication of being bothersome. One dictionary definition of noise is, “a sound, especially one that is loud or unpleasant or that causes disturbance.”   “Sound,” on the other hand, implies meaning, “a particular auditory impression.”

Nina Kraus, Professor of Communication Sciences, Neurobiology, and Otolaryngology at Northwestern University, has written an intriguing article for Scientific American that discusses new research that shows that our brains can actually tell the difference between noise and sound. Studies of brain waves, done at Northwestern, show that sound is understood by the brain while noise merely disrupts it.  And noise not only interferes with function, it can actually damage the brain:

Noise is more pernicious than an in-the-moment nuisance. Even a modest level of noise, over a long enough period of time (e.g. beeping garbage trucks, hair dryers, air conditioners), can cause damage to the brain networks that extract meaning from sound. Many of us don’t even realize our brains are being blunted and our thinking impeded by this invisible force.

So what can we do to protect our brains from damaging noise?  We can’t shut out all sound, because “the absence of meaningful sound also leaves a mark on the ability to process sound.”  Dr. Kraus adds that “there are distinct ways to tone and hone your listening brain.”  Namely:

You can learn a second language. The challenge of juggling two languages bolsters the auditory system and redounds to improvements in cognitive functions such as attention.

Another way to exercise your auditory brain is to play a musical instrument. This has a huge payoff cognitively and emotionally for children and adults alike. A few years of playing an instrument while in school sharpens the auditory system and can benefit language development in children. And this benefit lasts a lifetime.

Fascinating!  Even more supporting evidence for the goal of The Quiet Coalition: to make the world quieter, one decibel at a time.

Dr. Fink is a leading noise activist based in the Los Angeles area.  He serves on the board of the American Tinnitus Association, is the interim chair of Quiet Communities’s Health Advisory Council, and the founding chair of The Quiet Coalition, an organization of science, health, and legal professionals concerned about the impacts of noise on health, environment, learning, productivity, and quality of life in America.

Originally posted at The Quiet Coalition.

What can you do to protect your children’s hearing?

Doctors say kids are at higher risk for hearing loss. Dr. Rachel Wood, an audiologist with the LSU Health and Sciences Center, studies and treats hearing loss patients, and increasingly she is seeing younger patients. Dr. Wood says that there are a “growing number of factors that cause hearing loss.” One particular concern is that “[c]hildren especially can plug into their phone and crank up the volume, turn up the sound effects on video games, or even watch rock concerts on their computers.”

Dr. Wood finds headphones to be “especially troubling,” stating:

There are tiny sensors in your inner ear that are very sensitive. Loud sounds damage those sensors, and if they’re destroyed, they will never grow back, which leads to hearing loss. The amount of damage is based on the volume of the sound and how close the sound is to your ear. Since headphones put the sound right next to those sensors, it magnifies the damage.

So what can you do to protect your child’s hearing?  Dr. Wood suggests that parents set volume limits on electronic devices such as phones.  She also advises parents to impose time limits for using headphones and have their children take a break every 30 to 60 minutes.  Finally, if your children are going to events with loud noises, such as concerts or fireworks displays, hand them a pair of ear plugs.  Purchased in bulk, ear plugs are a cheap and easy way to protect your children’s hearing.

 

 

 

Hearing loss may double in the U.S. by 2060

Photo credit: Thomas Widmann

CBS News reports on a new study that concludes that millions of Americans face the prospect of losing their hearing as they age. The study by researchers at Johns Hopkins University estimates that “[a]mong American adults 20 and older, hearing loss is expected to increase from 44 million in 2020 (15 percent of adults) to 73.5 million by 2060 (23 percent of adults),” with the greater increase among older Americans. As a result, “there will be an increased need for affordable interventions and access to hearing health care services.”  Says lead study author Adele Goman, “[h]earing loss is a major public health issue that will affect many more adults,” and “to address this issue, novel and cost-effective approaches to hearing health care are needed.”

Or perhaps prevention would be a better tactic?

Dr. Debara Tucci, a spokesperson for the American Academy of Otolaryngology, Head and Neck Surgery, would agree. She tells CBS News that “people aren’t doomed to lose their hearing as they age.” “The most common cause of hearing loss is prolonged exposure to loud noise,” adds Dr. Tucci, “which includes loud music and a noisy workplace.”  Prevention, then, should be a rallying call among the medical profession, particularly public health officials.  This is especially important since the litany of horribles that befalls older adults who suffer hearing loss goes well beyond difficulty hearing.  The list includes: higher incidences of depression and anxiety, higher rates of hospitalization and of falls, and even “evidence of an association between hearing loss and mental decline.”

Coupled with the recently released and updated information concerning hearing loss from the Centers for Disease Control and Prevention, this study is a wake-up call to the medical and audiology professions and the public. Simply put, there is a low-cost and 100% effective way to tackle noise-induced hearing loss–preventing it from occurring in the first instance.

 

 

 

The CDC takes on noise-induced hearing loss

Photo credit: Raed Mansour

Dr. Daniel Fink, Chair of The Quiet Coalition, writes about the “flurry of activity” at the Centers for Disease Control and Prevention (CDC) with regard to noise-induced hearing loss (NIHL). Dr. Fink states that in the past the CDC offered “a lot of information about occupational noise exposure” and “screening neonates for congenital deafness,” but had no advice for the general public about noise.

But that has changed.

From May 2016, the CDC has issued a Morbidity and Mortality Report and Vital Signs publication on NIHL, and just recently posted new or recently revised information about how loud noise damages hearing and advice to seniors on preventing NIHL. While he isn’t surprised by the CDC’s robust response to what they identify as the “third most common chronic health condition in the US,” Dr. Fink notes that he and the other founding members of The Quiet Coalition are grateful that the CDC has stepped up efforts to help protect the nation’s hearing health.

It’s World Hearing Day!

By Daniel Fink, MD

Today, March 3, is World Hearing Day. This day is designated by the World Health Organization (WHO) to raise awareness and promote ear and hearing care around the world. The theme of this year’s World Hearing Day is “Action for Hearing Loss: Make a Sound Investment,” which aims to draw attention to the economic impact of hearing loss and cost effectiveness of interventions to address it.

I wish the WHO and the U.S. federal government paid a little more attention to prevention of hearing loss rather than dealing with the consequences after the damage has been done. The “public health mantra” is that prevention is better and cheaper than treatment, which in turn is better and cheaper than rehabilitation. I know that many people think hearing loss is part of normal aging, but several lines of evidence suggest that most hearing loss is caused by noise exposure. Presumably most people think they can just get a hearing aid when their hearing goes, unaware that hearing aids don’t work as well for hearing loss as eyeglasses work for presbyopia. And noise-induced hearing loss is entirely preventable–just avoid loud noise. If you can’t avoid noise, use earplugs.

Helen Keller said decades ago, “Blindness separates people from things. Deafness separates people from people.”  The New York Times recently had a column about blindness, the most dreaded physical disability.  If people were losing vision instead of losing hearing from noise exposure, people might be more concerned about our too noisy world.

A sobering article on a severe form of hyperacusis:

Photo credit: Epic Fireworks

When even soft noises feel like a knife to the eardrums. Joyce Cohen, writing for Statnews.com, introduces us to Tom Maholchic, who suffers from a severe form of hyperacusis where noise is felt as physical pain. Most people who have hyperacusis find ordinary environmental sounds to be uncomfortably loud, but a more severe form, like that which Maholchic has, is far more debilitating. For Maholchic “routine sounds — the sizzle of bacon, the ring of a phone, the rush of running water,” feels “like a knife stabbing his eardrums.”

Cohen explains that while researchers have known about hyperacusis for years, very little was know about the more severe form, until very recently:

Using new lab tools and techniques, pioneering scientists have identified what appear to be pain fibers in the inner ear, or cochlea. They are coining new terms, including “noxacusis” and “auditory nociception,” for this newly recognized sensation of noise-induced ear pain.

Cohen gives us an overview of the difficulties researchers confronted in attempting to learn more about nerve fibers within the cochlea, “a tiny sensory organ buried within a skull bone [that is] tough to reach and impossible to biopsy.”  But, nonetheless, advances have been made.  And for sufferers like Maholchic these new findings will help them get some understanding about a condition that “[f]ew doctors or audiologists are even aware of.”

Most importantly, as the research continues and hyperacusis becomes more generally known within the medical community, one hopes that general practitioners and other medical professionals will advise their patients to avoid exposure to loud sound. As Cohen writes, noise loud enough to cause immediate pain is rare, “[b]ut exposure over time to more modest noise — from music, movies, sirens, lawnmowers, and a thousand other everyday things — can damage hearing and set off the pain fibers.”  Maholchic didn’t think his noise exposure was unusual–he said he listened to his ipod while vacuuming, played in a garage band, and worked at a lively restaurant–but one day his ears started ringing and shortly thereafter the pain began.  Even if the research advances quickly and a treatment or cure is found in Maholchic’s lifetime, no doubt he would agree that preventing the condition would have been the better option.

 

Do We Hear too Much Noise Every Day?

Dr. Daniel Fink believes the answer is yes. Noted noise activist, Daniel Fink, MD, Founding Chair of The Quiet Coalition, writes about his thesis that the general public is exposed to entirely too much damaging noise every day. He notes that noise is a public health hazard, yet the federal government, which adopts standards to protect the public for food, water, and motor vehicles and makes recommendations or guidelines for dietary intakes of vitamins, salt, and sugar, has issued no federal standard regulating noise exposure or recommending noise limitations for the public.  In his piece, Dr. Fink describes his quest to find the noise level that will protect hearing, and he reveals how a recent important but ignored study has confirmed his suspicions that hearing damage can occur at lower decibel levels than previously suspected.

Click the link above to read more about Dr. Fink’s mission to warn medical professionals, the government, and the public about the dangers of noise and how we can protect our hearing.