Tag Archive: hidden hearing loss

AARP on hidden hearing loss

Photo credit: Ken Lund licensed under CC BY-SA 2.0

by Daniel Fink, MD, Chair, The Quiet Coalition

This piece from the AARP discusses hidden hearing loss, although it really discusses the “speech-in-noise” problem. The speech-in-noise problem has been known for decades. Namely, people, usually in mid-life or older, complain that they can’t understand speech in a noisy environment, typically a restaurant, but their hearing tests are normal.

Recent research suggests that these people suffer from what is now called hidden hearing loss. Hidden hearing loss is an inability to process speech in noisy environments. It is called “hidden” because standard hearing tests (pure tone audiometry) are normal, but more sophisticated testing used only in research settings finds abnormal processing of complex sounds. The likely cause of hidden hearing loss is damage to the nerve endings in the inner ear, called cochlear synaptopathy. This scientific article discusses the problem in greater detail.

To me, there are two takeaway lessons from the AARP piece. The first is that the speech-in-noise problem is very common in older people.

The second is that this piece is a call to action. AARP advises us to seek out quieter settings, sit in a restaurant booth, or put the noise behind us and the speaker in front of us.

But the piece assumes that noisy restaurants are an inevitable part of life.

I would advise AARP members to ask the manager to turn down the amplified music. If they refuse, walk out or threaten to file a lawsuit under the Americans with Disabilities Act. And on your way out, tell management that the restaurant is too noisy and you refuse to eat there.  Make sure to note the restaurant’s indifference to your comfort and hearing health in a detailed review on social media, and let your city council representative know about the problem, too.

Restaurant patrons used to have to dine accompanied by unwanted secondhand cigarette smoke. When secondhand smoke was found to be a Class A carcinogen with no known safe level of exposure, we were able to get smoking banned. We have a right to dine without endangering our health.

Noise is also a health hazard, to our hearing and our cardiovascular health. Just as we are entitled to smoke-free restaurants, we have a right to quieter restaurants, too.

Dr. Daniel Fink is a leading noise activist based in the Los Angeles area. He 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. Dr Fink also is the interim chair of Quiet Communities’ Health Advisory Council, and he served on the board of the American Tinnitus Association from 2015-2018.

Why can’t you hear?

Photo credit: Helena Lopes from Pexels

by Daniel Fink, MD, Chair, The Quiet Coalition

This piece in the Canadian edition of Psychology Today asks “Why can’t you hear?,” but a better title might be “Why can’t you understand speech in a noisy room?”

This problem is known in audiology circles as the “speech in noise” problem. People can understand what someone is saying just fine in a quiet room, but can’t follow a conversation in a noisy one. The problem has been known for decades, but now it is thought that the cause is cochlear synaptopathy, also called hidden hearing loss because hearing test results–technically known as pure tone audiometry–are normal despite the patient’s complaints of not being able to hear.

The problem can be assessed clinically by a number of tests, including the Hearing in Noise Test and the QuickSIN test. Now researchers at the Massachusetts Eye and Ear Infirmary have developed two tests, one measuring pupillary responses and the other recording electrical signals from the ear drum.

The inability to understand speech in noise is a frustrating one. Hearing aids usually don’t help much, although newer digital hearing aids with special features claim to do better.

Much better than any hearing aid, though, is preserved natural hearing. Protect your ears. If something sounds too loud, it is too loud. Turn down the volume, use hearing protection, leave the area, or you might have speech n noise difficulty later.

Dr. Daniel Fink is a leading noise activist based in the Los Angeles area. He 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. Dr Fink also is the interim chair of Quiet Communities’ Health Advisory Council, and he served on the board of the American Tinnitus Association from 2015-2018.

A test for hidden hearing loss?

by Daniel Fink, MD, Chair, The Quiet Coalition

This report from Science Daily discusses research at the Massachusetts Eye and Ear Infirmary, trying to find a test that will diagnose hidden hearing loss. Hidden hearing loss is hearing loss not detected by routine pure-tone audiometry, so patients complain of being unable to understand speech in normal environments but their hearing test is normal.

Right now, testing for hidden hearing loss is not clinically available, so any test that may help diagnose this common condition would be welcome.

Dr. Daniel Fink is a leading noise activist based in the Los Angeles area. He 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. Dr Fink also is the interim chair of Quiet Communities’ Health Advisory Council, and he served on the board of the American Tinnitus Association from 2015-2018.

Popular Science looks at hidden hearing loss

Photo credit: Maurício Mascaro from Pexels

by Daniel Fink, MD, Chair, The Quiet Coalition

This well-written article in Popular Science discusses hidden hearing loss. Hidden hearing loss is caused by damages to the nerve junctions between the cochlear hair cells and the auditory nerves. It’s called “hidden” because the damage isn’t detected by standard pure tone audiometry tests, only by more sophisticated testing. Patients complain that they can’t understand what people are saying in crowded or noisy situations, but the audiologist tells them, “Your hearing is fine. There’s no problem.” For decades, this was known as the “speech in noise” problem.

It turns out that there is a problem, and it’s caused by damage to the nerve junctions, which interferes with processing of the sound by the nervous system.

The problem of understanding speech in noise, which is most likely a manifestation of hidden hearing loss, isn’t rare. Approximately 10-20% of adults appear to have it, and it may even be more common in those of middle-to-older age.

More evidence supporting the need for us to protect our ears from loud noise.

Dr. Daniel Fink is a leading noise activist based in the Los Angeles area. He 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. Dr Fink also is the interim chair of Quiet Communities’ Health Advisory Council, and he served on the board of the American Tinnitus Association from 2015-2018.

Hidden hearing loss

Photo credit: Daria Shevtsova from Pexels

by Daniel Fink, MD, Chair, The Quiet Coalition

Hidden hearing loss is the term used to describe nerve damage in the inner ear (cochlear synatptopathy) which causes hearing loss detected only by special research techniques, not by standard hearing testing (pure tone audiometry). That’s why it’s called “hidden.” The clinical manifestation of hidden hearing loss is thought to be difficulty understanding speech in a noisy environment, but auditory training might help improve understanding of speech in noisy places.

This article describes a survey of adults who were asked if they would be willing to participate in auditory training. What’s of interest to me is that 22% of adults surveyed report having difficulty understanding speech in a noisy environment. That fits with other reports I’ve seen, but I think it’s an underestimate.

Many people with hearing loss think their hearing is excellent, and I think the same is true for people asked about difficulty understanding speech in a noisy environment. Due to the stigma of hearing loss, no one wants to admit that he or she has a problem.

More importantly, if people have difficulty understanding speech in noisy environments, it would seem to be much easier to make those environments quieter, rather than offering auditory training to those with the problem.

Quieter environments would make it easier for everyone to converse, and would prevent auditory damage in those without it.

Dr. Daniel Fink is a leading noise activist based in the Los Angeles area. He 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. Dr Fink also is the interim chair of Quiet Communities’ Health Advisory Council, and he served on the board of the American Tinnitus Association from 2015-2018.

When “good news” is bad news

Daniel Fink, MD, Chair, The Quiet Coalition

This article in JAMA Otolaryngology about hearing loss in young people age 12-19 is getting press as good news. Researchers at the University of California (both the Los Angeles and San Francisco medical schools) analyzed audiometric test data on young Americans from the National Center for Health Statistics collected by National Health and Nutrition Survey (NHANES). The researchers concluded that the prevalence of hearing loss as measured by standard pure tone audiometry had not increased despite wider use of headphones and earbuds to listen to personal music players.

We don’t think this is good news at all.

First, the researchers state that the prevalence of hearing loss in 2009-2010 is 15.2%. Hearing only worsens with age, so based on the data, it appears that about one-sixth of young people are likely to have profound hearing loss in mid-to-late life. If they were losing their vision instead, would anyone think this was good news?

Second, the subjects hearing was assessed by standard pure-tone audiometry. These traditional tests do not detect hidden hearing loss, which indicates nerve damage (synaptopathy) caused by noise exposure. Only techniques that are now considered research techniques will detect this early auditory damage.

Third, the authors note that there was increased risk of hearing loss in racial/ethnic minorities and those from low socioeconomic backgrounds. Isn’t hearing health an issue for this group of Americans too?

Finally, the researchers discuss the many limitations of this type of data analysis, which means that no definite conclusions can be drawn from this study.

In the end, the article generated a lot of “good news” headlines and in doing so has done a disservice to all young people, because those headlines and the cursory reports that followed downplay the dangers of increased headphone and earbud use. This is particularly galling and irresponsible when one recognizes that noise-induced hearing loss is 100% preventable.

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.

New drug may prevent hearing loss after noise exposure

By Daniel Fink, MD, Chair, The Quiet Coalition

For many years, a body of research has shown that chemicals with antioxidant properties might prevent or reduce hearing loss after noise exposure. In animals, noise exposure reduces levels of a chemical called glutathione peroxidase 1 (a naturally occurring enzyme). A recent report in the British journal The Lancet looks at how a similar chemical, ebselen, works in helping to reduce “both temporary and permanent noise-induced hearing loss in preclinical studies.”

It appears to work quite well.

Of course, we at The Quiet Coalition think it’s better just to avoid loud noise exposure, which is 100% safe and effective at preventing hearing loss. That said, the experimental protocol raises interesting questions about research ethics. Namely, the study tested the efficacy of different doses of ebselen after the subjects, healthy adults aged 18–31 years, were exposed to loud sound. The measure of ebselen’s success was the prevention of a phenomenon called temporary threshold shift (TTS), more completely noise-induced temporary threshold shift (NITTS). This audiometric measure has been used for decades to measure the impact of noise on humans.

Unfortunately, recent research, beginning with a 2009 report and updated last year describes a phenomenon called “hidden hearing loss,” a synaptopathy (injury to the synapses in the cochlea) caused by noise exposure. Hidden hearing loss is called that because it is not detected by standard audiometric techniques. Hidden hearing loss is the likely cause of being unable to follow one conversation among many in a noisy environment, or having a normal or near-normal audiogram but still having difficulty understanding speech.

Many experts think that there is no temporary auditory damage. That is, TTS is a real phenomenon but the use of the word “temporary” is misleading because if TTS occurs then it is likely that permanent auditory damage has also occurred.

In this study, healthy young adults were exposed to noise levels loud enough and long enough to cause TTS, likely indicating permanent auditory damage. Some of the subjects were given large enough doses of the experimental drug ebselen to prevent TTS from occurring, but whether the drug would or wouldn’t work, and at what dosage, wasn’t known when the study began. Simply put, the study exposed all subjects to the threat of auditory damage, and most likely caused auditory damage in the subjects who received the placebo or didn’t get a high enough dose of the experimental drug.

All research protocols in the U.S. must pass review by an Institutional Review Board (IRB) which must make certain that steps are taken to prevent harm to research subjects.. Under the Helsinki Declaration of the World Medical Association, and in the United States under what is called the federal “Common Rule” (45 CFR §46 et seq.), human subjects must be protected. If there is a risk of permanent auditory damage when the phenomenon of TTS is observed–and Drs. Liberman and colleagues certainly think that temporary auditory changes denote permanent auditory damage–we think the IRB should have done more to protect the subjects from any possibility of harm.

How could a study that exposes young people to noise levels loud and long enough to cause TTS pass IRB review? We hope the federal Office for Human Research Protections will let us know.

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.

New explanation for why older people can’t hear in noisy environments

Photo credit: Filipe Fortes licensed under CC BY-SA 2.0

By Daniel Fink, MD, Chair, The Quiet Coalition

There are already several explanations about why middle-aged and older people can’t understand speech in noisy environments. One may just be high-frequency hearing loss caused by noise, which makes it hard to hear the higher-pitched consonant sounds (F, S, SH, T, V) that allow us to differentiate similar sounding words (Fear, Sear, Shear, Tear, Veer). (See the graph in this CDC Vital Signs Issue.) Another reason may be a phenomenon called “hidden hearing loss,” which is caused by noise damage to nerve junctions (synapses) in the inner ear.

And now a new report indicates that there may also be a brain or central processing problem. A study conducted at the Max Planck Institute in Germany, “analyzed what happens in the brain when older adults have trouble listening in loud environments.”  The researchers “monitored the brains of 20 younger adults ages 18 to 31, and 20 older adults in their 60s and 70s, during a listening task” in which constant background noise was played while participants were told to focus on certain targeted sounds.

What the researchers found was that “the younger adults were able to zero in on the target signals while filtering out the irrelevant noise,” but the older participants had “a harder time tuning out the background noise.” What remained unclear was whether the “degradation of the ear’s ability to hear actually leads to a decline in the brain’s ability to filter out noise and hear a single sound,” or whether “the brain’s listening ability erodes independently of any changes going on in the ear.”

As for why older people have a difficult time understanding speech in noisy environments, it most likely is that all three factors occur to varying degrees in various individuals. But one thing is certain, preventing hearing loss is simple: avoid loud noise. And improving the ability of people young and old to follow conversations is also simple: turn down the volume in indoor places.

Link via the UK Noise Association.

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.

 

Revisiting the routine audiological test

By Daniel Fink, MD, Chair, The Quiet Coalition

An audiology examination involves examination of the ear to inspect the ear drum, and then tests based on the patient’s complaints. Routine audiology testing includes pure tone audiometry, i.e., can the patient hear sound at different standard frequencies at different volumes? The recording of these responses is graphed into an audiogram:

Image credit: Courtesy of Dr. Stephane Maison

Tests of speech comprehension can also be performed.  But more detailed tests, such as DPOAE (Distortion Product Oto-Acoustic Emissions), and BAER (Brainstem Auditory Evoked Responses) are not routinely done. They are reserved to further investigate suspected problems, or used as research techniques.

But none of these tests can detect the phenomenon of “hidden hearing loss,” a synaptopathy caused by noise damage to slow response nerves and nerve junctions in the cochlea.

Dr. Stephane Maison, a leading researcher at Harvard Medical School and the Eaton-Peabody laboratory at the Massachusetts Eye & Ear Infirmary, recently published two important papers. The first, Toward a Differential Diagnosis of Hidden Hearing Loss, documented hearing loss in young musicians that was not detected by standard pure-tone audiometry but was detected by more sophisticated tests. In his paper, Dr. Maison wrote that his study “aimed to test the hypothesis that ‘hidden hearing loss’ is widespread among young adults with normal audiometric thresholds, especially those who abuse their ears regularly.” To test this theory, they “recruited young adult subjects and divided them according to noise-exposure history into high-risk and low-risk groups.” What he and his team found were “significant deficits in difficult word-recognition tasks in the high-risk group that were associated with significant elevation of pure-tone thresholds at frequencies higher than those normally tested and with changes in auditory evoked potentials consistent with the presence of cochlear synaptopathy, also known as hidden hearing loss.”

In the second paper in The Hearing Journal, he recommends that additional tests should be added to the current audiometry protocol to detect hidden hearing loss. Dr. Maison argues that early detection must be done since “[n]oise damage early in life likely accelerates the age-related further loss of hair cells and cochlear neurons, even in the absence of further ear abuse,” and suggests that additional tests be administered to identify hidden hearing loss, noting that “recent animal research has reported regeneration of cochlear nerve synaptic connections with inner hair cells after noise exposure.” He concludes that “[c]larification of the true risks of noise, and the true prevalence of noise-induced damage, are important to public policy on noise abatement, to raising general consciousness about the dangers of ear abuse and to preventing a dramatic rise in hearing impairment in the future.”

Click the links above to read Dr. Maison’s papers. They are 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, 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.

 

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?