Tag Archive: study

Another study shows association of hearing loss with cognitive decline

Photo credit: Xiaofan Luo licensed under  CC BY-NC-SA 2.0

by Daniel Fink, MD, Chair, The Quiet Coalition

We have reported previously on associations between hearing loss and dementia in the U.S., and studies finding brain changes associated with decreases in auditory input due to hearing loss. Hearing loss is also associated with depression.

This study from China, published in JAMA Network Open, confirms these associations in a different population. The China Health and Retirement Longitudinal Study is following a nationally representative survey of adults age 45 and older, and their spouses. The current study looked at data from 18,038 participants with an average age of 59.9. Hearing impairment was associated with worse performance in episodic memory, mental intactness, and global cognition and a greater risk of depression.

Correlation is not causation, but this report from another country with a different language and culture confirms studies in the U.S. and Europe. It’s another piece of the puzzle in trying to understand why some people develop certain problems as they age. Research is ongoing to elucidate how hearing loss contributes to or causes cognitive decline, and whether providing hearing aids can prevent or slow cognitive decline.

In the meantime, we urge people to protect their hearing as assiduously as they protect their vision. We don’t stare at the sun. We wear sunglasses when outdoors. And we should view hearing loud noise just like staring at the sun. Loud noise is as dangerous for the ears as the sun is for the eyes.

Because if something sounds loud, it’s too loud, and auditory health is in danger.

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.

Poor hearing associated with brain changes

Photo credit: Andrea Piacquadio from Pexels

by Daniel Fink, MD, Chair, The Quiet Coalition

Bryan Pollard, founder of Hyperacusis Research, Ltd., is an electrical engineer. Almost every time I have discussed something with him, he asks me an important question: “What’s the cause? What’s the effect?”

It is very easy to make a mistake thinking that an association is causal when it is not.

One of the best ways to avoid making this mistake is to study a phenomenon over time. If a factor in some research subjects is associated with changes over time, and absence of that factor is not associated with the change being examined, causality is more likely.

A good example of this question is the association of hearing loss with the development of dementia. Maybe hearing loss causes dementia because there is decreased nerve stimulation of certain parts of the brain related to auditory and speech processing, but maybe the brain changes are independent of hearing loss or perhaps even the cause of the hearing loss.

This recent report in JAMA Otolaryngology-Head and Neck Surgery, with an accompanying editorial, uses the study of brain changes over time to try to answer this question. The research was done on the well-studied population of the Baltimore Longitudinal Study of Aging. Hearing tests and studies of brain tissue using specialized research techniques were done. Imaging was done by MRI at the National Institute of Aging.

Results showed that poorer hearing at baseline was associated with specific changes in portions of the brain processing auditory input, but not in other areas of the brain. The editorial notes the limitations of the study and its preliminary nature, but the report is another piece of the puzzle linking hearing loss to dementia.

For at least five years, I have been saying, “If it sounds too loud, it IS too loud.” But based on the accumulating evidence of the dangers of noise for hearing loss, and then the impact of hearing loss on social function, economic success, and the development of dementia, I’ve decided to change my advice.

Now I would say, “If it sounds loud, it IS too loud.”

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.

Research during COVID: Biologist studies bird behavior and noise

Photo credit: Tina Nord from Pexels

by David M. Sykes, Vice Chair, The Quiet Coalition

I wondered who was taking advantage of this pandemic-induced quiet to do research on how nature reacts? Sure enough, this young researcher at the College of William and Mary in Virginia is conducting a well-controlled study of the nesting and reproductive behavior of bluebirds–with and without the influence of traffic noise.

Fascinating experimental design. If you’ve heard of other studies, please let us know!

David Sykes chairs several professional organizations in acoustical science: QCI Healthcare Acoustics Project, ANSI Committee S12-WG44, the Rothschild Foundation Task Force on Acoustics, and the FGI Acoustics Committee. He is lead author of “Sound & Vibration 2.0” (Springer, 2012), a contributor to the NAE’s “Technology for a Quieter America” and the GSA’s “Sound Matters,” and co-founded the Laboratory for Advanced Research in Acoustics at Rensselaer Polytech. A graduate of UC-Berkeley with advanced degrees from Cornell, he is a frequent organizer of professional conferences in the U.S., Europe, Asia and the Middle East.

Could noise be a risk factor for hypertension?

Photo credit: Kateryna Babaieva from Pexels

by Daniel Fink, MD, Chair, The Quiet Coalition

Could noise be a risk factor for hypertension? This fascinating study from Chengdu, China, suggests that the answer is yes. The study design is innovative. The investigators measured bilateral high frequency hearing loss (BHFHL) and blood pressure in 21,000 workers, with an average age of 40. Hearing loss was a proxy measure for occupational noise exposure. Workers with greater hearing loss, as measured by audiometric tests, had a greater risk of also having high blood pressure.

The study is an exploratory one, and it is cross-sectional, i.e., the workers were not followed for decades and the study is based on one-time measurements of hearing and blood pressure. Other factors known to be associated with hypertension, such as weight and alcohol consumption, were not documented. And only a proxy measure of occupational noise exposure, bilateral high frequency hearing loss, was used, rather than actual noise measurements in the workplace. But the number of workers studied was large enough to provide high statistical significance, and the results were striking. As the researchers noted, “subjects having mild and high BHFHL had a higher hypertension risk of 34% and 281%, respectively (both P<0.001). Dose-response relationship between BHFHL and hypertension was found in both males and females.”

Studies done in the U.S. also show a correlation between occupational noise exposure and hypertension. The Chinese study may show a stronger relationship between occupational noise exposure and hypertension because workplace protections and their enforcement may be less stringent in China than in the U.S.

What are the implications of this study for public health? More than 100 million Americans have high blood pressure. At least two studies show that noise exposure in everyday life is great enough to cause hearing loss. Is it also great enough to contribute to the epidemic of hypertension in the U.S.?

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.

Sleep may be good for your salary

Photo credit: Ivan Oboleninov from Pexels

by Daniel Fink, MD, Chair, The Quiet Coalition

This fascinating article in The Ne York Times reports on a new study by economists showing that those who sleep more have higher salaries. The study correlated incomes with the earlier sunset times in the eastern end of a time zone compared to the western end, e.g., Boston, Massachusetts vs. Ann Arbor, Michigan, where there’s about a 50 minute difference between sunset times.

I wonder if another factor might be at work. Those who earn more can afford to live in quieter neighborhoods. Those who earn less can’t afford to do that. In fact, a study done by researchers at the University of California, Berkeley, showed that noise pollution was worse in poor and minority communities.

Might the researchers have mixed up cause and effect? Probably not, because according to the report they looked at average incomes in the different areas in the same time zone.

But one does have to wonder.

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.

Michigan scientists studying the natural soundscape

Photo credit: Kaique Rocha from Pexels

by Daniel Fink, MD, Chair, The Quiet Coalition

This report from the Michigan Science Center describes how scientists and artists are studying the natural soundscapes there.

Nature is quiet without human noise.  Natural sounds includes birds chirping, squirrels chattering, waves splashing on the shore, and wind in the trees.

The soundscape can also be studied as an indicator of environmental health, because natural quiet is good for animals, good for people, and good for the environment.

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.

Animal study may have implications on human hearing issues

Photo credit: Батяшев Александр licensed under CC BY-SA 3.0

by Daniel Fink, MD, Chair, The Quiet Coalitionhttps://creativecommons.org/licenses/by-sa/3.0/deed.en

I’ve only read the press release and the abstract for this paper in JNeurosci but the findings are interesting. In chinchillas–a common animal model for hearing research–scientists at the University of Rochester and Purdue University found that mild noise-induced hearing loss also caused changes in nerve processing of auditory signals.

This may have implications for humans in terms of the very common “speech in noise” problem, in which people with normal audiograms complain that they can’t understand a conversation if the ambient noise level is moderate to high.

But to me, the most important implication of this study is that it emphasizes how important it is to protect our ears.

The only evidence-based noise exposure level to prevent hearing loss is a time-weighted average of 70 decibels a day and even that low level of noise exposure may be too high.

According to the World Health Organization, only one hour at 85 A-weighted decibels is enough to cause hearing loss.

The CDC states that noise-Induced hearing loss is entirely preventable.  Avoid exposure to loud noise, or wear hearing protection if one can’t.

Because if something sounds too loud, it IS too loud.

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.

Columbia project on hearing loss focuses on the brain

Photo Credit: This U.S. Army graphic is in the public domain

by David M. Sykes, Vice Chair, The Quiet Coalition

The hearing loss space is attracting investment again after nearly four decades of being starved for funding. New York City’s Columbia University is working on a project that shows us what investors are looking into: the hidden parts of hearing that involve brain circuitry.

The Columbia project, unlike some of the others I’ve discussed before, won’t deliver anything practical for a very long time, but it’s still pretty interesting. Until recently hearing researchers focused on the ear and assumed that was the important part. But it turns out that the wiring between the ear and brain, specifically the regions of the brain involved in hearing, is where the action is now. In part, that’s because there’s been such a surge of federal and private money pouring into brain research over the past decade.

The Columbia research team is looking at how they might train hearing aids to distinguish the voices of specific people—the people you want to hear and nobody else. Right now, that would involve implanting electrodes into your brain–that’s what happens if you get a cochlear implant–but they’re hoping to be able to do this eventually with external devices.

What the researchers are addressing is what’s known as the Lombard Effect, discovered a century ago by the French physician Etienne Lombard, and also known as the “cocktail party effect.” It’s one of the first signs of hearing loss and consists of an inability to understand “speech-in-noise.” Example: you’re in a noisy space like a club or a party, and you’re trying to understand what your companion is saying but you’re unable to do so because of the background noise. Sound familiar? If so, you–like nearly 50 million Americans–have hearing loss.

No, there’s nothing you can do about it. Not yet. So we recommend you follow this Columbia project to see what happens next.

In addition to serving as vice chair of the The Quiet Coalition, David Sykes chairs several professional organizations in acoustical science: The Acoustics Research Council, American National Standards Institute Committee S12, Workgroup 44, The Rothschild Foundation Task Force on Acoustics, and the FGI Acoustics Working Group—a partner of the American Hospital Association. He is the lead author of “Sound & Vibration 2.0 (2012, Springer-Verlag), a contributor to the National Academy of Engineering report “Technology for a Quieter America,” and to the US-GSA guidance “Sound Matters”, and co-founded the Laboratory for Advanced Research in Acoustics (LARA) at Rensselaer Polytechnic Institute. He recently retired from the board of directors of the American Tinnitus Association. 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.

Another drug trial to prevent noise-induced hearing loss

by Daniel Fink, MD, Chair, The Quiet Coalition

This press release from the Washington University School of Medicine in St. Louis says that the medical school is receiving a $10 million grant from the Army to test whether an epilepsy drug can prevent noise-induced hearing loss.

The study population includes patients undergoing surgical procedures requiring use of noisy drills and police officers.

While I’m glad that people who can’t avoid loud noise may have an option that will offer them some level of protection, for most of us it’s a whole lot easier to prevent noise-induced hearing loss by just avoiding exposure to loud noise.

Remember, if it sounds too loud, it IS too loud.

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.

Hearing loss associated with depression

by Daniel Fink, MD, Chair, The Quiet Coalition

I’m not sure this new report on the association between hearing loss and depression in older Hispanic people in JAMA Otolaryngology adds much to our knowledge of how hearing loss affects people. It has been known for some years that hearing loss is associated with depression in older people. The report extends the research to Hispanic people in several large cities, but as best as I can tell, that’s the only new information. The authors claim that this study’s importance is that it measured hearing loss rather than relying on reports of hearing difficulties, but some earlier studies did that, too.

In older people it’s hard to tell if the hearing loss was caused by noise or not, because over time changes indicating hearing loss from noise lose specificity as hearing loss becomes worse. But my analysis of the literature suggests that what is commonly called age-related hearing loss, as in the JAMA Otolaryngology article, is really noise-induced hearing loss, which is entirely preventable.

Now that the connection between hearing loss and depression is clear, doesn’t it make sense for government and the medical community to commit resources to educate the public about the dangers of noise-induced hearing loss? A host of health concerns will diminish or disappear if we focus on stopping noise-induced hearing loss.

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.