Tag Archive: noise induced hearing loss

Hearing Restoration: A Step Closer?

Photo credit: Ronna Hertzano et al. licensed under CC BY 2.5

By Daniel Fink, MD, Chair, The Quiet Coalition

A recent report that scientists in Boston have caused human hair cells to regrow in the laboratory is exciting news, holding out the promise of hearing restoration in the future.

But it is important to remember two facts:

1. Development and then approval of this technology for human use are likely to be years if not decades in the future, and the technology will most likely be very expensive.

2. Noise-induced hearing loss is 100% preventable and prevention is either free or inexpensive: avoid loud noise exposure and use hearing protection (ear plugs or ear muffs) if one can’t.

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.

 

Why do humans suffer hearing loss from noise?

Image is in the public domain in the U.S.

By Daniel Fink, MD, Chair, The Quiet Coalition

Why do humans suffer hearing loss from noise? The cellular, sub-cellular, and even molecular reasons for how noise damages the auditory system are known, but why?

In a fascinating article in The Hearing Journal, evolutionary biologist William Shofner, PhD, notes that humans and our animal forebears evolved in a largely quiet environment. Exquisitely acute hearing was important for finding prey or avoiding threats, but resistance to noise damage in the auditory system conferred no selective advantage.

Our world only started getting noisy as cities evolved, and especially since the Industrial Revolution. That is, our ears haven’t evolved to handle the noise, hence the epidemic of noise-induced hearing loss reported by Centers for Disease Control and Prevention.

Shofner’s last paragraph says it all:

Why didn’t evolution make the ear more noise-resistant? Again, evolution does not proceed with purpose. Simply stated, the human ear did not evolve under conditions of high sound levels. Any genetic mutation that might have led to a noise-resistant ear was likely not selected because it did not provide any benefit for survival and reproductive success in the pre-historic acoustic environment of early mammals. Natural selection is an exceedingly slow process that occurs over many generations, and the susceptibility of the human ear to noise-induced damage shows how natural selection is unable to keep up with rapid changes in an organism’s environment (Evol Applications. 2008). Technology has produced an acoustic environment that has changed much faster than the sluggish pace of human evolution. This evolutionary explanation of why the human ear is so susceptible to damage at highly intense noise levels provides a valuable perspective that audiologists can offer patients to prevent NIHL.

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.

Millions of people don’t protect their ears

Photo credit: Quinn Dombrowski licensed under CC BY-SA 2.0

By Daniel Fink, MD

Noise is a medical and public health problem, and yet people ignore it at their own peril. Most of us are exposed to too much noise every day. That may explain why the Centers for Disease Control and Prevention found that about 25% of adults age 20-69 had hearing loss, and that many people with hearing loss didn’t know they had it.

Which is why a recent article by Mark Fischetti in Scientific American,A Loud Warning: Millions of People Do Not Protect Their Ears,” is particularly disturbing. Fischetti reports that while “many people know that they should use earplugs or earmuffs when mowing the lawn or partying at the club,” they don’t protect their ears against noise at home or at work. If you click the link to the article, you’ll see a frightening infographic that very clearly shows that millions of Americans are at risk of losing their hearing or suffering other hearing damage because they fail to protect their ears.

Maybe if people knew that noise caused hearing loss, tinnitus, and hyperacusis–none of which can be cured–they might be motivated to protect their hearing and fight for quiet.

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.

Experts: Hearing loss is on the rise among young adults

Photo credit: Stefan Schmitz licensed under CC BY-ND 2.0

and their personal audio devices may be at least partially to blame. Melanie Campbell, a professor of Rehabilitation Medicine at the University of Alberta, warns that young adults “may be destined to swap out their headphones for hearing aids.” The problem is that this cohort “particularly loves music, they love it loud and they have very few worries about the future.” Campbell notes that World Health Organization statistics show that “[m]ore than one billion young adults are at risk of hearing loss,” and “[a]mong people aged 12-35 years, almost half are exposed to dangerously high levels of noise from personal audio devices like headphones while four out of 10 are exposed to unsafe levels of sound at concerts and other entertainment venues.”

According to Campbell, the primary cause for this hearing loss these days is noise-induced hearing loss (NIHL). What makes hearing loss particularly insidious, is that people generally don’t lose their hearing overnight. Instead, says Campbell, “[i]t creeps up and you gradually forget that you’re not hearing the door squeak, or you don’t hear people’s heels on the floor.”

To give young Canadians the information they need to protect their hearing and prevent hearing loss, Campbell has been promoting Sound Sense, a project led by the Hearing Foundation of Canada that spreads awareness about hearing loss in Canadian schools.

Spreading awareness about NIHL and how to prevent it is, of course, the the best option. Every school in the U.S. should regularly test students’ hearing and include information about NIHL in their health education programs. Given that NIHL is 100% preventable, the failure to educate children about how they can avoid NIHL is as insidious as the disorder.

 

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.

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.