Hidden Hearing Loss

New Yorker writer worries about her ears–you should be worried, too

Photo credit: Scott Robinson licensed under CC BY 2.0

by Daniel Fink, MD, Chair, The Quiet Coalition

New Yorker staff writer Amanda Petrusich is worried about what noise is doing to her ears.

She’s right to be worried. We all should be worried.

As the world has gotten louder–perhaps because “everyone knows” that 85 decibels is safe because the National Institute for Deafness and Other Communication Disorders tells us “long or repeated exposure to sound at or above 85 decibels can cause hearing loss”–a vast uncontrolled experiment is taking place in the U.S., with 320 million subjects.

Gregory Flamme and colleagues showed that 70% of adults in Kalamazoo County, Michigan got total daily noise doses exceeding Environmental Protection safe noise levels for preventing hearing loss.

Not surprisingly, researchers at the Centers for Disease Control reported a year ago that 25% of American adults have noise-induced hearing loss, including many people without any occupational noise exposure.

Remember, if it sounds too loud, it IS too loud! If you can’t carry on a normal conversation without straining to speak or to be heard, the ambient noise is above 75 A-weighted decibels, which also happens to be the auditory injury threshold.

Your ears are like your eyes or your knees. You only have two of them. Keep them away from loud noise and they should last you your entire life.

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.

Noise is causing hearing loss in traffic police in India

Photo credit: GPS licensed under CC BY-SA 2.0

by Daniel Fink, MD, Chair, The Quiet Coalition

This report from the Indian city of Pune documents hearing loss in traffic police. Apparently car horns are the main culprit. So how bad could it be?  This bad:

A study of 46 traffic personnel “found that 39 of the 46 traffic personnel could not pick up high frequency tones, indicating alarmingly high (83%) presence of noise-induced hearing loss (NIHL) among the city’s traffic police.”

And the damage isn’t limited to hearing loss, as “the traffic personnel were also screened for hypertension,” and “13 of the 46 traffic personnel have been diagnosed with hypertension, a condition they were unaware about.

I have traveled in India, although not to Pune, and it is a noisy country. The big cities–Mumbai and Delhi–are noisier than New York City, so this report isn’t a surprise to me.

But there’s no reason to believe that ears in India are different from ears in the U.S. Traffic noise causes hearing loss and other health problems in the U.S., too.

Perhaps India–and the U.S.–should follow Kathmandu’s successful effort at eradicating traffic noise, because it can be done if the political will exists.

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.

How likely are you to get tinnitus from clubbing?

by Daniel Fink, MD, Chair, The Quiet Coalition

This article from the UK asks the question: How likely are you to get tinnitus from clubbing?

The article points out that there really isn’t any way to predict who will develop tinnitus, i.e., ringing in the ears, after noise exposure, and that’s the most important thing to know.

I didn’t know that a one-time exposure to loud noise could cause tinnitus the rest of one’s life. I developed tinnitus (and hyperacusis, a sensitivity to noise that doesn’t bother others, with noise causing pain in the ear) after a one-time exposure to loud music in a restaurant on New Year’s Eve ten years ago.

Fortunately, there is one simple rule to protect your ears: if it sounds too loud, it IS too loud.

If you can’t carry on a conversation without straining to speak or to hear, the ambient noise is above the auditory injury threshold of 75 A-weighted decibels, and your hearing is being damaged.

Research done over the last decade strongly suggests that there is no temporary auditory damage. In animal models, loud noise damages the synapses (nerve junctions) in the ear before it damages the hair cells. This damage isn’t detected by standard hearing tests (pure tone audiometry) but likely is the major reason why adults have difficulty following one conversation among many in a noisy environment.

Remember, your ears are like your eyes or your knees–God only gave you two of them! Take care of them, and they will last you your whole life.

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.

Four in 10 UK adults unknowingly endanger their hearing on a daily basis

Photo credit: Gary J. Wood licensed under CC BY-SA 2.0

by Daniel Fink, MD, Chair, The Quiet Coalition

This report states that 40% of adults in the United Kingdom (England, Scotland, Wales) unknowingly endanger their hearing on a daily basis.

This finding fits neatly with Dr. Gregory A. Flamme’s report that 70% of U.S. adults get total noise doses exceeding safe limits and Dr. Richard Neitzel’s similar finding in a Swedish population.

This isn’t rocket science–noise exposure for the ear is like sun exposure for the skin. If you don’t want deep wrinkles, age spots, and skin cancers when you get older, wear a hat, long sleeves, sunscreen, and avoid the sun.

If you don’t want hearing aids when you get older, avoid noise exposure.

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.

Will earbuds ruin my hearing?

Photo credit: Marcus Quigmire licensed under CC BY-SA 2.0

by Daniel Fink, MD, Chair, The Quiet Coalition

The headline for this article in Time magazine is “Will earbuds ruin my hearing?” The short answer is that it’s not the earbuds or headphones that damage hearing, but the noise emanating from them. The longer answer follows.

The article widely cites Dr. Robert Dobie at the University of Texas Health Science Center at San Antonio who says that earbud use isn’t a problem.

It also cites Harvard researcher Dr. M. Charles Liberman, who, with Dr. Sharon Kujawa, discovered the phenomenon now known as hidden hearing loss. This is damage to nerve junctions (synapses) in the ear, called hidden because it is not detected by standard hearing tests.

Dr. Liberman says that earbud use might be a problem.

Dr. Dobie’s assertion that earbud use isn’t a problem sounds just like the doctors in the 1950s and 1960s who insisted that smoking cigarettes wasn’t harmful to health. We now know differently.

My conclusion is that noise causes hearing loss. The human ear was not designed to withstand loud noise exposure because such a tolerance offered no evolutionary advantage. As I wrote in the January 2017 American Journal of Public Health, the only evidence-based safe noise exposure level to prevent hearing loss is 70 decibels time-weighted average for a day. I further explained, in a requested blog post for AJPH, that the real safe noise exposure level is probably lower than that.

We know, from decades of research on occupational noise exposure that led to the occupational safety criteria for noise exposure, from the work of Liberman and colleagues, and from hundreds or thousands of studies showing that noise damages hearing in animals and humans with the cellular and sub-cellular mechanisms of how this occurs now precisely understood that noise causes hearing loss.

If you believe Dr. Dobie, continue to listen to your personal music player using earbuds or headphones.

If you don’t want hearing aids when you are older (and I don’t think hearing loss is part of normal aging, as I said at the 12th Congress of the International Commission on the Biological Effects of Noise in Zürich in June 2017) my advice is not to use earbuds.

Your ears are like your eyes or your knees. God only gave you two of them. Protect them and keep them safe and working well your entire life.

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.

Groundbreaking research proves restaurants are too noisy

by Daniel Fink, MD, Chair, The Quiet Coalition

New York based researcher Greg Scott presented a groundbreaking study Tuesday, December 5th, at the 174th meeting of the Acoustical Society of America in New Orleans, Louisiana. Mr. Scott reported actual decibel measurements, obtained using the free IOS SoundPrint app he developed, on almost 2,000 restaurants and bars in New York City. The average sound level was 78 A-weighted decibels (dBA) in restaurants, and 81 dBA in bars.

Even people with normal hearing can’t understand speech if the ambient noise is above 75 dBA, which is also the auditory injury threshold (the noise level at which hearing damage begins). People with moderate hearing loss–25-40 dB decrement in hearing–need ambient noise lower than 60 dBA to be able to understand speech.

The SoundPrint app is easy to use and can help find quieter restaurants and the rare quiet bar. But it is clear to me–as I stated in my own talk, which preceded Greg’s–that high ambient noise in restaurants and retail stores is a disability rights issue for people with hearing loss, tinnitus, and hyperacusis. The Americans with Disabilities Act (ADA) guarantees people with disabilities the full and equal enjoyment of places of public accommodation, which are basically any facility open to the public. If one can’t hear in a noisy place, one’s ADA rights are being violated. It is likely that legal action will be required to make these places quieter.

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.

Coping with hearing loss and noisy restaurants is not a game

by Daniel Fink, MD, Chair, The Quiet Coalition

This report from CNN discusses a novel strategy to help people with hearing loss understand speech: a game to train the brain to process speech better.

This is a widely known but poorly understood problem–sometimes called the “Speech in Noise problem”–with people with hearing loss, but it can also affect people with normal or adequate hearing as tested by standard hearing tests (“pure tone audiometry”) who nonetheless can have problems understanding speech.

The problem is worse for those with hearing aids, which is probably why up to 40% of people with hearing aids don’t use them–they just don’t help understand speech in everyday situations. As hearing loss blogger Shari Eberts has written, hearing aids just are not like eyeglasses.

Some research supports a central cause for this, i.e., deficiencies in brain processing of auditory signals as people age. Other research puts the problem in the periphery, i.e., the ear. And the research on hidden hearing loss puts the problem in between, in the nerves connecting the ear to the brain. Most likely the explanation involves all three.

Even though the computer game reported in this story may eventually help people who struggle to understand speech, dealing with hearing loss and noisy restaurants isn’t a game.

The real answer isn’t brain training. It’s quieter restaurants, stores, and other public places.

Quieter indoor places will not only help those who already have hearing loss understand speech, they will prevent hearing loss in those still with good hearing.

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.

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.