Noise Induced Hearing Loss (NIHL)

Massachusetts Medical Society: No to noisy leaf blowers

Photo credit: Hector Alejandro licensed under CC by 2.0

By Jamie L. Banks, PhD, MSc, Program Director, The Quiet Coalition

Are health concerns about gas-powered leaf blowers (GLBs) gaining momentum? On April 29th, the Massachusetts Medical Society (MMS) became the second in the nation to approve a resolution against GLBs, following the lead of the Medical Society of the State of New York (MSSNY). Other physician groups, such as Utah Physicians for Healthy Environment and Fresno Madera Medical Society, have also issued warnings on the use of GLBs and other fuel-powered lawn and garden equipment. The resolution brought by the society’s Committee on Environmental and Occupational Health and its chair Heather Alker, MD, MPH, recommends that the MMS:

  • Recognize noise pollution as a public health hazard, with respect to hearing loss;
  • Support initiatives to increase awareness of the health risks of loud noise exposure;
  • Urge the maximum feasible reduction of all forms of air pollution, including particulates, gases, toxicants, irritants, smog formers, and other biologically and chemically active pollutants; and
  • Acknowledge the increased risk of adverse health consequences to workers and general public from gas-powered leaf blowers including hearing loss and cardiopulmonary disease.

The growing concern on the part of the medical community over leaf blower noise is welcome news. Commercial GLBs can produce noise of 95 decibels and higher at the ear of the operator. This noise level exceeds safe occupational levels by an order of magnitude. The close proximity use of these powerful engines exposes both workers and others in the area to prolonged periods of excessive noise, not to mention toxic air pollutants. The presence of a low frequency component in the leaf blower’s frequency band distribution (i.e., the device’s sound signature) enables it to travel over long distances and through walls and windows.

The MMS resolution notes the harms to hearing and health from excessive noise produced by GLBs. Loud noise is known to cause hearing loss, tinnitus, and hyperacusis, as well as other health problems such as high blood pressure and heart disease. In addition, loud noise has negative effects on quality of life, communication and social interaction, work productivity, and psychological well-being.

The burgeoning use of GLBs and other fossil fuel powered equipment around our homes, schools, and other public spaces is a public health hazard, and a growing number of physicians and other health professionals are becoming concerned. The moves made by MMS and MSSNY are to be lauded, and other state societies and medical groups, including the American Lung Association and American Heart Association, need to prioritize this issue.  With the body of scientific evidence on the harms associated with noise and pollution, other state and national medical societies have a critical role to play in educating government officials and the public about the connections between environmental hazards and disease and the actions we can take to reduce risks in our communities.

Jamie L. Banks, PhD, MSc, is the Executive Director of Quiet Communities, Inc. and the Program Director of The Quiet Coalition. She is an environmentalist and health care scientist dedicated to promoting clean, healthy, quiet, and sustainable landscape maintenance, construction, and agricultural practices. Dr. Banks has an extensive background in health outcomes and economics, environmental behavior, and policy.

Source: Quiet Communities

Originally posted at The Quiet Coalition.

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?

Remember all those concerts you went to?

does, and he still is a regular concert goer since he’s been a music journalist for more than 30 years. He saw a lot of great shows, but he also learned the hard way that loud concerts take their toll. And he shares his hard-won knowledge in his excellent article, “You’re Losing Hearing Faster Than You Think.”

Browne starts his piece with a discussion about the increase in hearing loss, stating that it is “likely due to a constant assault of noise” and adding that we have “become so accustomed to blaring sound” that our definition of what is loud has changed. He interviews Robert Jackler, chair of otolaryngology at Stanford, who asks, “Are we going to see people lose their hearing at an earlier age, and lose it more severely as time goes by?,” and emphatically answers, “Yes.”

Browne talks about his concern for his own hearing as well as his daughter’s, adding that for as long as he knew him, his father wore a hearing aid. Browne looks at the stigma attached to hearing aids, noting that there is no stigma attached to wearing eyeglasses. Along with the stigma, there are the psychological manifestations of hearing loss, namely isolation and depression. This discussion follows Browne’s visit to an audiologist and his “sobering” results–a diagnosis of sloping high-frequency loss.

In light of his audiology exam, Browne’s goal for himself was to prevent further damage. To do that, his audiologist suggests two options: The first was to get fitted ear plugs to wear at loud events, and the second, which Browne found depressing, was that he consider getting hearing aids.

In the end, Browne opts for the ear plugs, “for now,” and he lists six things everyone can do to protect their hearing, including downloading a decibel meter and wearing ear plugs. To read the entire article and see the full list of protective steps, click the second link above.

 

 

Modern life is damaging our ears more than we realize

Photo credit: Global Jet

Rebecca S. Dewey, a research Fellow in Neuroimaging writing for The Conversation, addresses noise exposure, “the main cause of preventable hearing loss worldwide.” She cites a recently published study in The Lancet that “revealed that living in a noisy city increases your risk of hearing damage by 64%.” Why do cities increase the risk so dramatically? Dewey points to obvious sources–work noise at a construction site or recreational noise at a nightclub–but adds that people “might be exposed to loud noises so constantly throughout the day that you don’t even realise they are there.” She also notes that many of us engage in “self-harm”–that is, exposing ourselves via mp3 players and mobile phones to damaging noise levels “with little more than a disclaimer from the manufacturers.”

Why is this a concern? Because of strides researchers have made about how hearing loss develops, aided by the relatively recent discovery of “hidden hearing loss.” Dewey states that it used to be believed that “noise-induced hearing loss resulted from damage to the sound-sensing cells in the cochlea,” but recent studies have shown that “even relatively moderate amounts of noise exposure can cause damage to the auditory nerve – the nerve connecting the inner ear to the brain.”

Unfortunately, the standard audiology exam “measures hearing by finding the quietest sound a person can hear in a quiet environment,” but hidden hearing loss affects “the ability to hear subtle changes in loud sounds,” what is called “supra-threshold.” Supra-threshold hearing is used to “understand conversations in a noisy room or hear someone talk over the sound of a blaring television.” In short, a traditional hearing test can’t detect hidden hearing loss, and attempts to measure it by playing a recording of speech masked with background noise “depends a lot on the ability of the patient to understand and cooperate with the test.”

Fortunately, Dewey works on a team at University of Nottingham that is developing an objective test using MRI scans that will “detect hidden hearing loss by scanning the parts of the hearing system that connect the ears to the brain.” The goal is to “understand who is most at risk and act early to prevent further hearing loss.”

And prevention is key, because there currently is no treatment or cure for hidden hearing loss. So do yourself a favor and avoid loud noise when you can, use earplugs when you cannot, and lower the volume on your personal audio devices. One day there will likely be a good treatment available for hearing loss, but no one knows if that day is five, ten, 20, or more years away. Why gamble on a future cure when prevention works today?

Another review site tackles “kid-friendly” earbuds and headphones

And TJ Donegan, Reviewed.com, concludes that you should never let your kids use your earbuds. Why? His review finds that headphones and earbuds could be dangerous for your kids’ ears. Donegan starts his article by stating that as a father to a young daughter:

I feel like I need to constantly worry about her safety. Worse, every other day there’s some jerk online telling me to be terrified of something new. Well, today I’m that jerk, but this is important: your headphones may be dangerous.

Donegan notes that most people probably recognize that loud concerts can damage hearing, but adds that “researchers and groups like the World Health Organization and the Centers for Disease Control (sic) have established that routine exposure to moderately loud sounds can permanently damage your hearing, with up to 1.1 billion people at risk.” The risk is of particular concern for children, as they “frequently listen to music at max volume.” 

This point was driven home for Donegan who says that “when testing for our roundup of the best headphones for kids…we found that even something as simple as an Apple iPhone 7 Plus and the included earbuds can dramatically exceed the recommended levels at full volume, posing a risk after just a few minutes.”  In the course of testing volume-limiting, “kid safe” headphones, Donegan and his associates found that “many exceeded their own advertised maximum limits” or the safeguards were easy for children to remove. 

Donegan then explores the issue of “how loud is too loud,” stating that “though health experts have been studying this for decades, there isn’t a clear point at which damage is guaranteed to occur.”  He cites the “consensus” standard that holds that “you are at risk of noise-induced hearing loss if you’re exposed to an average volume of 85 decibels for 8 hours in a day,” but adds that “[i]t’s important to note that we’re not entirely sure where the safe zone really ends, and because noise-induced hearing loss is irreversible, caution is definitely the way to go.”  There is more than a hint of skepticism about safe standards in this article, as there should be.  As noted noise activist Dr. Daniel Fink has written in his editorial in the American Journal of Public Health, the 85 dBA standard is “an occupational noise exposure standard [that] is not a safe standard for the public.”

After an exhaustive review of hundreds of headphones, including 20 pairs of volume-limiting headphones, Donegan distills the findings into guidelines he plans on using when his daughter starts using headphones, including using volume-limiting headphones that play at or below recommended sound levels and limiting headphone use to under one hour a day.

To see Donegan’s full list of guidelines and learn more about the methodology used to review volume-limiting headphones, click the link in the first paragraph.

Link via @earables.

Is your home too noisy?

Here are six tips to make your world less noisy. Kathy Riggs, Utah State University Extension family and consumer sciences professor, writes about the National Institutes of Health’s campaign against noise-induced hearing loss called “It’s a Noisy Planet – Protect Their Hearing.”  Noting that “[t]his type of hearing loss can be permanent, but it is preventable,” Riggs provides six useful tips for limiting your family’s exposure to noise, including monitoring the volume of earbuds, keeping outdoor noises outdoor, and checking the noise rating of common household appliances.  Click the link to to read more about her tips for protecting your family’s hearing.

CDC research on non-occupational noise-induced hearing loss

The Hearing Journal addresses the Centers for Disease Control and Prevention’s (CDC) February 2017 Vital Signs issue on noise-induced hearing loss (NIHL), focusing on the CDC’s findings with regard to non-occupational NIHL. CDC scientists Yulia Carroll, MD, PhD, and John Eichwald, MA, write about the medical community inquiries the CDC received on the topic of hearing loss related to noise in non-occupational settings, and discuss the research relied on in producing the Vital Signs’ NIHL issue.

Carroll and Eichwald write that “[m]any people may not recognize that loud noise from common activities, such as mowing the lawn or attending sporting events, can be as loud as the noise found in the workplace and is enough to damage hearing.”  They note that “it is important to raise public awareness that the louder the noise and the longer the exposure, the more likely hearing damage will occur.” After all, prevention of disease is an important CDC goal, and, as the authors write, “[n]oise-induced hearing loss is a preventable health condition that can be avoided by using relatively easy measures.”

Unfortunately, “[t]here are no federal guidelines on safe noise exposures” for the public, but Carroll and Eichwald suggest that that could change:

Because noise-induced hearing damage accumulates over time, there is a need for future research about noise exposure and prevention at younger ages. CDC is working with various organizations and continues to analyze national data to prioritize public health needs.

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.

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.