Tag Archive: hearing loss

Better Hearing Month 2017 and the problem of noise

By David Sykes, Vice Chair, The Quiet Coalition

Every year since 1927, May has been designated “Better Hearing Month.” What better time to think about what threatens your hearing health? In fact, if you already have some hearing loss you’re one of about 48 million Americans—that’s many more than all of the people with cancer or diabetes combined.

That’s a big number, and yet hearing loss—specifically noise-induced hearing loss (NIHL)–has been overlooked and underfunded for three and a half decades.

Noise is such a simple word–why is it so complex and laden with jargon and specialists who don’t talk to one another? One group is solely concerned with how to measure it (physicists). Other groups focus on specific types and sources of noise, such as jet aircraft, or alarmed medical devices, or leaf blowers, or trains, or highway noise (engineers or advocacy groups). Others concentrate on the effects of noise on humans (doctors and public health researchers), while another group ponders how noise affects organisms other than humans, including plants, birds and other animal species, including those that live underwater (biologists). Still other groups think about how to mitigate noise (architects and designers).

The problem is that over the past three and a half decades, the subject of noise and it’s effects have been systematically ignored and underfunded by Congress and the White House. As a result, “noise”–the cause of NIHL–has become a bewilderingly fragmented field in which few people talk to others outside their own specialities. This has resulted in a subject that is hard to understand and laden with technical jargon. What is “noise”? Why does it matter? Who cares? Has the science progressed? If so, how and where?

But recently that has begun to change thanks to advances in research and to changes in federal policies from several federal agencies that have not traditionally been involved in noise and noise control. These include the Centers for Disease Control and Prevention, NASA, the Department of Health and Humans Services, the Department of Interior, the General Services Administration, the Joint Commission, and others.

In each case, a specific federal department has bitten off a chunk of the noise problem and developed guidelines and programs to fit their own needs. But put all of these disparate pieces together and you will find examples of real progress despite the fragmentation.

To help build general understanding, we ar the The Quiet Coalition have assembled some of these fragments into a diagram or a “Road Map” of noise effects (see chart above) organized by the way they are studied within various specialized fields. We hope this Road Map helps others see the big picture.

In addition to the Road Map, we have also assembled the basic facts about noise into a simple one-page “Fact Sheet” that provides detailed references to scientific literature. Both the Fact Sheet and the Road Map are starting points. At The Quiet Coalition, our goal is to synthesize the underlying scientific research on this complex and fragmented subject into a coherent picture so that we can collectively find ways to talk about it. We hope you find both the Fact Sheet and the Road Map useful as you think about hearing, hearing loss, and that elusive problem, noise.

The underlying question for each of us should be: how can we work together?

David Sykes chairs/co-chairs four national professional groups in acoustical science: The Acoustics Research Council, ANSI S12 WG44, The Rothschild Foundation Task Force on Acoustics, and the FGI Acoustics Working Group. He is also a board member of the American Tinnitus Association, co-founder of the Laboratory for Advanced Research in Acoustics (LARA) at Rensselaer Polytechnic Institute, lead author of “Sound & Vibration 2.0 (2012, Springer-Verlag), and a contributor to “Technology for a Quieter America” (2011, National Academy of Engineering). A graduate of the University of California/Berkeley with graduate degrees from Cornell University, he is a frequent organizer of and speaker at professional conferences in the U.S., Europe, Asia, and the Middle East.

The problems with hearing aids

Photo credit: Steve Johnson licensed under CC by 2.0

and the solutions. Manfred starts her piece with a stunning statistic: “A whopping 80 percent of adults between the ages of 55 and 74 who would benefit from a hearing aid do not use them.”  Why? For a variety of reasons: discomfort, disappointment with the sound quality, difficulty in using them, expense, and a fear of “wear[ing] something associated with ‘old.’” But what these people don’t realize, Manfred writes, is “the profound damage that uncorrected hearing loss can do to your physical, emotional and cognitive health.”

Click the link to read about the effect of hearing loss on the brain–it’s profound–and read Manfred’s responses to the various excuses people give for not getting a pair of hearing aids.  As she notes, they aren’t perfect, but it’s better to deal with little imperfection than the consequences of not wearing them.

Who should get their hearing checked? Everyone!

By Daniel Fink, MD, Chair, The Quiet Coalition

This local television anchor recommends that everyone get his or her hearing checked.

But this isn’t what the experts at the U.S. Preventive Services Task Force recommend. They reviewed the published medical literature on screening for hearing loss and concluded that, based on the literature, there is no proven benefit to screening for hearing loss in adults. People who complain of not being able to hear should be checked, they cautioned, but they found no benefit in looking for hearing loss is those who don’t have an obvious problem.

Maybe it’s time to rethink that recommendation. A recent report from the Centers for Disease Control and Prevention (CDC), Vital Signs: Noise-Induced Hearing Loss Among Adults, found the following based on recent data from the National Health and Nutrition Survey:

Results: Nearly one in four adults (24%) had audiometric notches, suggesting a high prevalence of noise-induced hearing loss. The prevalence of notches was higher among males. Almost one in four U.S. adults who reported excellent or good hearing had audiometric notches (5.5% bilateral and 18.0% unilateral). Among participants who reported exposure to loud noise at work, almost one third had a notch.

Conclusions and Implications for Public Health Practice: Noise-induced hearing loss is a signficant, often unrecognized health problem among U.S. adults. Discussions between patients and personal health care providers about hearing loss symptoms, tests, and ways to protect hearing might help with early diagnosis of hearing loss and provide opportunities to prevent harmful noise exposures. Avoiding prolonged exposure to loud environments and using personal hearing protection devices can prevent noise-induced hearing loss.

Audiometric notch is the hallmark of noise induced hearing loss.

The CDC information that a quarter of American adults have hearing loss but don’t know it–including those who rate their hearing as good or excellent–indicates a major problem. Experts recommend checking blood pressure at every doctor visit and cholesterol at varying intervals, depending on risk factors, beginning in childhood. Screening for auditory disorders is recommended for children but not for adults. But hearing loss is like high blood pressure or high cholesterol–it is painless and asymptomatic, and unless someone checks, the patient doesn’t know that he or she has it.

Why does this matter? Most Americans, including most doctors and audiologists, don’t know that the only safe noise exposure level to prevent hearing loss is only 70 decibels time weighted average for 24 hours with the real safe noise exposure level probably even lower than that. Most Americans don’t know that we are exposed to dangerous levels of noise every day, which probably explains the recent CDC findings. If people know that they have hearing loss, perhaps they will do more to protect their ears.

Significant hearing loss with age is probably not part of normal physiological aging, but represents noise-induced hearing loss. (I will be presenting a paper on that topic at the 12th Congress of the International Commission on the Biological Effects of Noise.)  Regular hearing testing could prevent current and future generations from losing their hearing.  Why? Because noise-induced hearing loss is 100% preventable, and regular tests would let people know whether and to what degree their hearing is compromised, allowing–and encouraging–them to take action today to avoid significant hearing loss tomorrow.¹

Take the initiative with regard to your hearing health, and have your hearing tested regularly as part of a preventive health plan.

Dr. Daniel 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 is 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.

¹ For those who are concerned about establishing the diagnosis of hearing loss as a pre-existing condition which might increase their insurance rates or exclude coverage for future hearing health care, they should not be worried for two reasons: (1) Medicare and Medicaid don’t have a pre-existing condition exclusion, and (2) federal and commercial insurance plans do not cover audiology services and hearing aids. Which is more important? Not establishing a pre-existing condition for something not covered by insurance, or finding out that your hearing is already being damaged and having the chance to take steps to protect your ears?

What Your Patients Don’t Know Can Hurt Them

Photo Credit: Flávia Costa licensed under CC BY 3.0

By Daniel Fink, MD, Chair, The Quiet Coalition

It looks like the truth about noise-induced hearing loss is finally getting out.  This article in The Hearing Journal, which claims to be “the most respected journal in hearing health care,” discusses the fact that noise causes hearing loss.  While hardly an earth shattering assertion, the article notes that “[h]earing loss has long been thought to be an unpleasant but inevitable side effect of aging.”  But, the article continues, “within the past year, two reports from the Centers for Disease Control and Prevention (CDC) have documented the startling degree to which noise—both in the workplace and elsewhere in our daily lives—contributes to hearing damage.”

What follows is a well-reasoned and complete discussion about noise-induced hearing loss. The article cites the new acting director of the CDC, Ann Schuchat, MD, and Rick Neitzel, PhD, the public health researcher and a co-founder of The Quiet Coalition. The only criticism I might offer is that the article doesn’t clearly state that the only safe noise level to prevent hearing loss is a daily average of 70 decibels time weighted average (see, “What Is a Safe Noise Level for the Public?“) and that the auditory injury threshold is only 75-78 A-weighted decibelsThose caveats aside, click the first link above to read the article.  It’s well worth your time.

Dr. Daniel 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.

On hearing loss and the hope for a cure

In “High-Tech Hope for the Hard of Hearing,” David Owen, The New Yorker, has written an article that gives us a good look at what scientists know about hearing loss and where they are finding possibilities for treatment and, possibly, a cure. He begins his article with a series of personal anecdotes about himself, his family, and friends and the hearing problems they’ve developed due to exposure to loud noise and other factors. Owen’s interest in this story is motivated, at least in part, by his tinnitus, which is marked by a constant high-pitched ringing in his ears.

Among the advances that Owen examines, he discusses the discovery of hidden hearing loss and introduces us to Charles Liberman, who, with his colleague Sharon Kujawa, “solved a mystery that had puzzled some audiologists for years: the fact that two people with identical results on a standard hearing test, called an audiogram, could have markedly different abilities to understand speech, especially against a background of noise.” He writes that “[s]cientists had known for a long time that most hearing impairment involves damage to the synapses and nerve fibres to which hair cells are attached, but they had assumed that the nerve damage followed hair-cell loss, and was a consequence of it.” What Liberman and Kujawa discovered is that “the connections between the sensory cells and the nerve fibres that go first.” And the reason this early damage isn’t picked up by a standard hearing test is because it measures “the ability to detect pure tones along a scale of frequencies [which] requires only functioning hair cells…and is unaffected by nerve damage until more than eighty per cent of the synapses are gone.”

“A disturbing implication of [Liberman and Kujawa’s] finding is that hearing can be damaged at decibel levels and exposure times that have traditionally been considered safe,” writes Owen, but he is reassured by the researchers that the discovery of hidden hearing loss is cause for optimism. Why? “[B]ecause reconnecting nerve synapses is almost certain to be easier than regenerating functioning hair cells inside human ears.” In fact, Owen tells us that Liberman and others “have successfully restored some damaged connections in lab animals, and [Liberman] believes that far greater advances are to come.”

While cause for optimism is welcome, Owen notes something early in his article that is particularly frustrating to those advocating for regulation of noise:

There are also increasingly effective methods of preventing damage in the first place, and of compensating for it once it’s occurred. The natural human tendency, though, is to do nothing and hope for the best, usually while pretending that nothing is wrong.

Click the link above to read this interesting and hopeful article in full.

 

 

Top researchers work toward treatments, but prevention remains the best medicine.

By Daniel Fink, MD, Chair, The Quiet Coalition

Humans are born with only 15,000 cochlear hair cells. When these are destroyed by noise they don’t regenerate, unlike cochlear hair cells in other animals, such as chickens. If a way can be found to regenerate human cochlear hair cells, perhaps hearing can be restored.

A recent report from Harvard and MIT holds promise for treating hearing loss in the future. Researchers there were able to increase the number of stem cells from mouse cochlear hair cells in vitro using a cocktail of small-molecule chemicals. It’s hard to do basic science research on humans–one can’t hurt people doing research–but mice share 99% of our genetic material, and being small and inexpensive, they are good substitutes in the lab. The researchers hope to begin testing their approach in humans in 18 months.

This is great news for millions of Americans with hearing loss. It’s possible that with additional advances, one day their hearing could be restored. But I have one problem with the report: The researchers are developing a treatment, probably not an inexpensive one, for a problem that is entirely preventable.

The public health mantra is that prevention is always better and cheaper than treatment, which in turn is better and cheaper than rehabilitation. Noise-induced hearing loss is 100% preventable. How? Avoid loud noise. If you can’t avoid noise exposure, use hearing protection (earplugs and ear muff hearing protective devices). You can find these in your drugstore, in “big box” home improvement stores like Home Depot or Lowe’s, or online. There is even an online retailer devoted only to hearing protection.

So kudos to the researchers at Harvard and MIT. No doubt their work and the work of other researchers will eventually help the millions of Americans who already suffer from hearing loss and other hearing damage. But let’s put time, money, and effort in promoting a cheaper and safer approach to hearing health–prevention. No more research is needed, and we can avoid hearing loss today.

Dr. Daniel 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.

Attention city dwellers

Mimi Hearing Technologies, a German company that has developed an app that allows users to test their ears for a personalized music experience, has issued their World Hearing Index. What does it do? Mimi found that “the average city dweller has a hearing loss equivalent to 10-20 years older than their actual age.”  So for World Hearing Day, the company developed the Worldwide Hearing Index “to draw attention to this global issue.”  To create the index they analyzed data from their Mimi hearing test app and paired their data with “research from the World Health Organization (WHO) on noise pollution in 50 cities internationally.” The end result is a ranking of world cities based on hearing loss.

Click the first link to see where your city ranks.

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 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.