Medical and scientific news

Noise disrupts sleep. Could this be linked to Alzheimer’s?

Photo credit: Alyssa L. Miller licensed under CC BY 2.0

by Daniel Fink, MD, Chair, The Quiet Coalition

The most common definition of noise is “noise is unwanted sound.” We at The Quiet Coalition recently came up with a new definition: noise is unwanted and/or harmful sound. The specific evidence-based sound levels associated with adverse health and public health hazards are summarized in my article in Acoustics Today, “Ambient Noise Is ‘The New Secondhand Smoke.'”

Sounds as low as 30-35 A-weighted decibels* can disrupt sleep. Uninterrupted sleep is important for both daily function and health. Nighttime noise is increasing, caused by aircraft noise, road traffic noise, emergency vehicle sirens, horn-based alerts, and sounds from clubs, bars, and concerts, with the specific noise source(s) depending on where people live.

It has been known since 2013 that sleep is necessary for cellular cleaning functions in the brain. A new study, reported by NPR, extends this research to Alzheimer’s disease. It has been known for some time that poor sleep is associated with Alzheimer’s disease, and patients with Alzheimer’s disease don’t sleep well. The new study shows that there are waves of cerebrospinal fluid occurring every 20 seconds during sleep, preceded by electrical activity. The electrical waves appear as slow waves on an EEG. Those with Alzheimer’s disease have fewer slow waves on their EEGs.

I have only read the NPR report, not the underlying article in Science, and I’m not 100% sure the cause-effect relationship between sleep disruption and Alzheimer’s has been clearly established. Which really came first, the sleep problems or the Alzheimer’s disease? Nonetheless, the study underscores the importance of a good night’s sleep.

Noise pollution is a public health problem. And one wonders if the increase in Alzheimer’s disease is due in part to increased nighttime noise levels.

*A-weighting adjusts sound measurements to reflect the frequencies heard in human speech.

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.

Another treatment for tinnitus

Photo credit: Dr. Craig Hacking and Prof Frank Gaillard licensed under CC BY-SA 4.0

by Daniel Fink, MD, Chair, The Quiet Coalition

This report from the University of California San Francisco discusses a Phase 1 trial of deep brain stimulation for tinnitus. A Phase 1 trial is a preliminary trial to see how a new treatment works. Then there are Phase 2 and Phase 3 trials.

Most treatments do not pass all the hurdles to be approved for regular use. And deep brain stimulation is expensive and risky.

By comparison, prevention of most forms of tinnitus is cheap, easy, and safe: avoid head trauma and noise exposure and one is unlikely to develop tinnitus.

That sounds like a much better idea than deep brain stimulation to me.

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.

Venture money surges into hearing health treatments

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

I’ve been watching Dr. Charles Liberman’s company, Frequency Therapeutics, for several years. He’s the physician-researcher who runs Harvard’s Lauer Tinnitus Research Center in Boston and who has published papers starting in 2009 about “hidden hearing loss,” papers that broke open the Congressional log-jam that prevented significant funding going into hearing disorders. His company has raised an eye-popping $228 million in venture capital–that’s a LOT for an early-stage company–and now they’ve gotten approval from the Food and Drug Administration to fast-track trials of their first product.

But Frequency Therapeutics isn’t the only company in this space. I recently saw information at an investor conference showing that another half dozen companies have also raised significant amounts of venture capital for hearing-disorder treatments. Collectively, they’ve raised over a quarter of a billion dollars! That’s extraordinary progress for a long overlooked sector where nothing seemed to happen for decades and where the only treatment option for decades were extraordinarily expensive hearing aids from a handful of powerful companies charging inflated prices no one could afford.

Now there’s an active market and venture capitalists are diving in! That is a real sign of progress!

Thanks are due to the President’s Council of Advisers on Science and Technology that in 2016 published a report on the noise-induced hearing loss market, and to the National Academy of Medicine report on hearing loss in America that issued a few months later. Those two reports also led to the bi-partisan Warren-Grassley OTC Hearing Aid Act that President Trump signed into law in 2018 and that goes in to effect in January 2020. That act, in turn, has created a surge of investment in personal sound amplification products, or PSAPs, which are high-tech ‘hearing aids’ you’ll soon be able to buy from your local drug store for 1/10th the price of conventional hearing aids.

Change is here!

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.

Genetic susceptibility to hearing loss from noise exposure

by Daniel Fink, MD, Chair, The Quiet Coalition

This article in The Hearing Journal reviews research on genetic susceptibilities to hearing loss from noise exposure. The author notes that 34 genetic variants have been reported to show an association with increased susceptibility to hearing loss from noise exposure. She concludes that “[f]urther work on the genetic and cellular bases of NIHL could enable the characterization of individual susceptibilities and help prevent this widespread disease.

Actually, additional work isn’t needed to help prevent noise-induced hearing loss (NIHL).  Additional research is always good, but the molecular bases of NIHL are very well understood.

Even better understood is how to prevent it: Avoid exposure to loud noise, leave the noisy environment, or wear hearing protection of one can’t do either. The CDC states that NIHL is 100% preventable.

Because noise exposure causes hearing loss, and 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.

Unilateral hearing loss may affect brain processing of sound

Photo credit: Colin Behrens from Pixabay

by Daniel Fink, MD, Chair, The Quiet Coalition

This report from Harvard Medical School states that chronic conductive hearing loss, a condition that can result from repeated middle-ear infections, may interfere with speech recognition.

People with unilateral hearing loss are often reluctant to wear a hearing aid on one side because their good ear allows them adequate hearing. But researcher Stephane Maison and colleagues found that people with unilateral conductive hearing loss, such as that caused by chronic ear infections, appeared to develop changes consistent with neural damage found in hidden hearing loss.

Based on this research, Maison and colleagues recommend that clinicians and patients should consider treating unilateral hearing loss to prevent neural deficits that can lead to difficulty understanding speech in noisy environments.

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.

Speech discrimination begins in the womb

Photo credit: lunar caustic licensed under CC BY-SA 2.0

by Daniel Fink, MD, Chair, The Quiet Coalition

A recent report looks at new research demonstrating that speech discrimination begins in the womb.

That’s not surprising. Gulls don’t speak, but they communicate danger by their cries, and the New York Times reported that the ability to recognize danger cries also begins in the egg!

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.

Music festival noise stresses out research fish

Photo credit: Kathy licensed under CC BY 2.0

by Daniel Fink, MD, Chair, The Quiet Coalition

This report in the Miami Herald discusses how noise from the Ultra Music Festival “stressed out” fish kept at the University of Miami for research purposes. Toadfish, a common species in Miami’s Biscayne Bay, were more stressed than if they had heard the clicking sounds made by dolphins, which are a major predator for toadfish.

“So what we’re talking about here and what our data show presently is that Ultra was causing a short-term acute stress on our fish,” said Danielle McDonald, a University of Miami associate professor. “We don’t know and we cannot conclude whether this stress would have persisted over time,” she added.

I’m pretty sure the stress would have persisted.  Animals evolved in quiet, with sound detection being an important method of finding food for predator species, or avoiding being eaten for prey species.

In humans, noise exposure causes involuntary physiological stress responses, including increases in heart rate, blood pressure, stress hormone levels, and vascular inflammation

The one question I haven’t seen answered is whether voluntary noise exposure causes the same physiological stress responses as involuntary noise exposure. The fish obviously didn’t want to attend the rock concert, but the lab facility in which they lived was close enough to the music festival that they had to hear the music. Did the same changes occur in those who paid their hard-earned money to attend the festival?

If anyone has seen a research study answering this question, please let us know.

Thanks to Sherilyn Adler, PhD, at the Ear Peace Foundation in Miami, Florida for bring this article to our attention.

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.

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.