Medical and scientific news

How a tsunami revealed human noise pollution

 

Photo credit: Calbear22, photo released into the public domain

Phys.org reports how a tsunami that struck Hawaii in 2011–caused by the same earthquake that hit Japan and created the tsunami that triggered the Fukushima nuclear disaster–caused a temporary halt to boat traffic that allowed scientists “a rare glimpse into what the bays might sound like without human activities.” By luck, the tsunami hit while “a Duke University-lead team was recording underwater sound in four bays” on Hawaii’s Kona coat.

It turns out that oceans are pretty loud. On the day of the tsunami, the loudest part of the day reached 98.8 decibels. Why are oceans so loud? “Because sound waves travel and are amplified differently in water than in air.” But 98.8 decibels was quiet compared to a reading on a typical day, as noise from boat traffic can reach up to 125 decibels, and the sound from nearby sonar exercises tops 143 decibels.

So what did the Duke study conclude? It showed that humans created the loudest disruptions and boat traffic and sonar were “significant causes of noise in all four bays.” Human-made noise has long been a concern of conservationists who fear that “interactions caused by dolphin-encounter boat tours and other human activities” are disrupting dolphins’ sleeping behaviors and potentially interfering with their hunt for food, since dolphins rest in the bays during the day to ready themselves for the hunt at night.

There is nothing inevitable or natural about chronic disease

Photo credit: Robbie Sproule licensed under CC BY 2.0

by Daniel Fink, MD, Chair, The Quiet Coalition

This thoughtful piece talks about chronic disease, pointing out that it is not inevitable or natural. The author, Dr. Clayton Dalton, writes that:

[T]raditional cultures across the globe, from hunter-gatherers to pastoralists to horticulturists, have shown little evidence of chronic disease. It’s not because they don’t live long enough – recent analysis has found a common lifespan of up to 78 years among hunter-gatherers, once the bottlenecks of high mortality in infancy and young adulthood are bypassed. We can’t blame genes, since many of these groups appear to be more genetically susceptible to chronic disease than those of European descent.

So what is the reason for the absence of chronic illness among these cultures? “Evidence suggests it is how they live,” Dr. Dalton replies. And what factors do these different cultures share?  Dr. Dalton writes that the “common denominator [is] defined by the absence of modern banes: absence of processed foodstuffsabsence of sedentary lifestyle, and likely absence of chronic stressors.”

Dr. Dalton doesn’t specifically mention noise-induced hearing loss, but that’s another chronic disease that he could have included in his essay.

I spoke about this at the 12th Congress of the International Commission on the Biological Effects of Noise in Zürich in June. Similar to Dr. Dalton’s comments about hypertension and diabetes, I presented information showing that significant hearing loss is probably not part of normal aging, but represents noise-induced hearing loss.

A useful analogy for noise and hearing is sun and the skin. It turns out that skin and subcutaneous tissues sag as we age–that’s normal–but deep wrinkles, age spots, and skin cancers are the result of ultraviolet exposure. Similarly, I’m sure there are changes that occur in our hearing as we age, but profound hearing loss (25-40 decibel decrement in hearing) is most often the result of noise exposure.

In the end, how we live our lives matters. If we want to hear well into old age, we have to work to preserve our hearing all during our lives. How? It’s easy: avoid loud noise or wear ear protection if you 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.

Noise discriminates–heavier burden unfairly borne by the poor and non-white

Photo credit: Alicia Nijdam licensed under CC BY 2.0

by Daniel Fink, MD, Chair, The Quiet Coalition

Noise exposure has multiple effects on humans–it causes auditory disorders, interferes with learning, and disrupts sleep, causing increased cardiovascular disease and death, among other things. A new analysis of socioeconomic, racial, and spatial variation in noise exposure in the U.S. shows that the poor and nonwhite have greater exposure to noise than wealthier and nonminority populations.

Life may not be fair, but governments have a responsibility to try to make it more fair, and to protect all citizens from harm: rich and poor, white and non-white, native-born and immigrant. Those who often refer to the U.S. Constitution often seem to forget this, but the preamble includes a mandate to “promote the general Welfare.” A quieter environment for all Americans would appear to be part of this.

This also happens to be current federal law. The Noise Control Act of 1972 is still on the books, even if the Environmental Protection Agency’s (EPA) Office of Noise Abatement and Control (ONAC) was defunded in 1982. Reasonable people understand that the EPA and ONAC will not be properly funded during this current administration, but at some future time the funding must be made available. Noise damages more than hearing, and it is simply unacceptable that poor and nonwhite Americans suffer greater noise exposure while the federal government stands by and does nothing to protect them.

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.

“Health attacks” by inaudible sonic waves are real

Photo credit: Tess Watson licensed under CC BY 2.0

James Hamblin, The Atlantic, writes about the attacks on American and Canadian diplomats in Cuba in his article, “What Are Sound Weapons?” Hamblin starts his piece by describing the incidents which caused several Havana-based diplomats to suffer headaches, balance issues, and even severe hearing loss. Secretary of State Rex Tillerson, Hamblin notes, refered the to incidents as “health attacks.” And the AP reported that “U.S. officials concluded that the diplomats had been attacked with an advanced sonic weapon that operated outside the range of audible sound and had been deployed either inside or outside their residences.”

The weaponization of “energy waves with frequencies outside the range that the human ear can detect” is not new, writes Hamblin, and the health effects from exposure to inaudible sonic waves are real. Hamblin shares the story of residents of Kokomo, Indiana, who in 2001 experienced “annoyance, sleep disturbance, headaches, and nausea.” The U.S. National Institutes of Health investigated the matter but “couldn’t pin down the cause of the Indiana residents’ symptoms as infrasound.” The report, however, “did confirm that infrasound can cause fatigue, apathy, hearing loss, confusion, and disorientation.”

In the end, U.S. officials don’t know if Cuba is responsible or some third party, with the suggestion offered that the actor could have been “Russia, China, North Korea, Venezuela, or Iran.” But Hamblin adds that the attack is hardly sophisticated, as “[n]oise-induced hearing loss affects around one in four people,” although the source of noise is more mundane for most of us: loud concerts, shooting guns, and everyday failures to protect our hearing. Says Hamblin, “fascination with this sort of attack can be a reminder that it is worth arming ourselves in daily life against the more quotidian forms of sonic weaponry.”

Another adverse effect of traffic noise

By Daniel Fink, MD, Chair, The Quiet Coalition

New research in Denmark shows that people exercise less when they live near noisy roads. The researchers found that for every 10 decibel increase in traffic noise, people were 5% less likely to exercise.

In general, a few simple habits can have a dramatic effect on health and longevity:

  1. Don’t smoke
  2. Eat fruits and vegetables
  3. Maintain a healthy weight, and
  4. Exercise regularly.

Anything that discourages healthy habits–and traffic noise now seems to fall into this category–is bad for health.

And the reason why traffic noise seems to decrease exercise? It isn’t clear. It may be that traffic noise disrupts sleep, so people exposed to the noise just lack the energy to get moving, but whatever the reason this study provides yet another reason why cities must control traffic noise.

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.

Quiet aircraft coming to an airport near you?

Photo credit: Pedro Aragão licensed under CC BY-SA 3.0

By David Sykes, Vice Chair, The Quiet Coalition

People who live near airports have struggled with noise for over 50 years. The first attempts to address this problem began in 1967, literally 50 years ago! But frankly, there’s been more progress on this issue outside the U.S., where, for example, the World Health Organization has addressed the burden of disease from environmental noise and the European Union has established night noise guidelines for Europe.

Meanwhile, here on American soil, the struggle continues with groups like the Congressional Quiet Skies Caucus and regional Quiet Skies groups experimenting with different approaches. A variety of strategies have been tested with varying success: petitions, fines, law suits, noise curfews, legislation, even complete airport shutdowns. Every American community that has confronted this issue realizes it’s a tough, long, uphill battle against powerful regulatory agencies and corporations that are more committed to commerce than to public health and welfare.

So, why can’t Boeing or somebody just make a quiet aircraft?

Actually they can—that is, the EU conglomerate Airbus canand already does. And the world’s largest passenger airplane, also made by Airbus–the A380–is the quietest both inside and out. So this isn’t a technological problem. Rather, aircraft engineers, manufacturers (other than Airbus), and the airlines that buy their planes, don’t seem to care about the impact of their products on those on the ground.

Interestingly, the quiet jet engine on the Airbus A320neo is made by the American company Pratt & Whitney.

Hooray! So why don’t U.S. airlines buy the A320neo equipped with its quiet jet engines? Wouldn’t this help to address the aircraft noise problem?

Good question.

For U.S. residents there’s also this good news: a new NASA program to develop quiet electric aircraft was recently announced, but the quiet electric aircraft are small propeller craft, so this is the kind of innovation you’ll see at smaller local airports in a few years.

What about helicopters? Can they make quiet helicopters too? The answer is yes again. Quiet, electric helicopters are also in development.

Conclusion? Maybe “technology substitution”–which works in other sectors–is the uniquely American way out of this dilemma.

At any rate, government-funded research and development (R&D) efforts by NASA and Pratt & Whitney demonstrate that somebody is listening! And in typical American fashion, it appears we will invent our way out of the airport noise mess by convincing the government to accelerate funding of both public and private sector R&D—from which entrepreneurs and business titans will reap rewards later.

At The Quiet Coalition and our host, Quiet Communities, we believe that local and regional anti-noise groups might have greater success if, in addition to the other strategies they’re already trying, they also emphasize “technology substitution.” This approach has worked well in cities and towns on issues like:

– leaf blowers and lawn mowers (convince your parks and recreation department to buy electric!);
– motorcycles (get them off Harleys and onto quieter electric motorcycles);
– appliances (the best-selling dishwasher these days is made in Germany and has become very popular worldwide because it’s quiet);
– air conditioning equipment (the best-selling household air-conditioning equipment is the quiet kind from Korea called “mini-splits” that were engineered to be quiet); and
– outdoor concerts (where wireless headsets are replacing noisy outdoor concert venues).

So our tech-driven American approach to “progress” may eventually get us to a quieter end-state—but the emphasis is on eventually.

In the meantime, until quieter times arrive, those of us who live near airports will have to either continue wearing earplugs or maybe experiment with the new “smart earbuds” that are now available.

And don’t forget the final option: move to a quieter neighborhood where your house isn’t underneath a flight path! Because you might have to wait a while before the above solutions arrive.

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 former board member of the American Tinnitus Association, co-founded the Laboratory for Advanced Research in Acoustics (LARA) at Rensselaer Polytechnic Institute, served as lead-author of “Sound & Vibration 2.0 (2012, Springer-Verlag), and was 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.

Scientists discover that eardrums move in sync with eyes

By Daniel Fink, MD, Chair, The Quiet Coalition

Aylin Woodward, New Scientist, reports on new research that shows that our eardrums appear to move to shift our hearing in the same direction that our eyes are looking. Jennifer Groh, the lead researcher, believes “that before actual eye movement occurs, the brain sends a signal to the ear to say ‘I have commanded the eyes to move 12 degrees to the right’.” Why? She opines that “[t]he eardrum movements that follow the change in focus may prepare our ears to hear sounds from a particular direction,” noting that one reason why the eyes and ears move together may be to help “the brain make sense of what we see and hear.”

My guess is that for our primate ancestors, and then for primitive humans, there was a survival advantage to hearing sound from something that had been seen. Friend or foe? Food or predator? It will be interesting to see where this research leads, particularly as Woodward writes that the study might help develop better hearing aids, “which must locate where sounds are coming from to work well.”

Research is always good. That’s how we learn about how the world works. But we don’t need any more research to know that noise is a health and public health hazard, and that we need to press our elected officials to make the world quieter now.

Because no matter how good the technology becomes, preserved normal hearing is far better than any hearing aid. And far cheaper, too.

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.

Bicyclists at risk of hearing loss

By Daniel Fink, MD, Chair, The Quiet Coalition

A new study shows that bicycle riders may be at risk of hearing loss, and the culprit is wind noise. The study by Dr. Michael Seidman, an ear specialist who also is a bicycle rider, measured sound levels in a wind tunnel, finding that under many conditions noise level were high enough to cause auditory damage. The measurements need to be replicated on the road, which is a more challenging endeavor.

To me, the important thing to note is how Dr. Seidman conceived of the study: he was out riding with his brother and found that they had to shout at each other to be heard over the wind noise. He states that “OSHA, the Occupational Safety and Health Administration, says you can be exposed to 85dB of loudness for an eight-hour time period at work. But that does cause noise-induced hearing loss — we know that it does,” he said. “So anything over 85dB causes noise-induced hearing loss.”

I wrote about the 85 dB (actually A-weighted decibels, or dBA) occupational standard in the American Journal of Public Health, in which I noted that 85 dBA “is not a safe noise exposure level for the public.” Humans have difficulty understanding speech if the ambient noise is above 75 decibels. (Technically, those are A-weighted decibels, or dBA. That information is in Figure D-1 in the 1974 EPA “noise levels” monograph.) And Flamme et al. discussed the fact that the auditory injury threshold is only 75-78 dBA.

So, as Dr. Seidman realized, if it sounds too loud, it IS too loud. You don’t need a sound meter to know that. If you have to strain to speak or to hear conversation, the ambient noise is above 75 dBA and your hearing is being damaged.

What should bicyclists do to protect their hearing? Earplugs are an obvious choice, but Dr. Seidman says that they are illogical because “It’s not a good idea to wear earplugs when you ride — you can’t be aware of your surroundings.” He suggests that helmet design could address wind noise (but apparently isn’t offered at this time), but adds that accessories are available, such as AirStreamz Pro Cycling Wind Noise Reducer  by Cat-Ears, which are attached to eyeglasses or helmet straps and help to deflect noise.

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.

Treating hearing loss may help prevent dementia

By Daniel Fink, MD, Chair, The Quiet Coalition

A recent Canadian newspaper article discussing a report in The Lancet, the premier British medical journal, about preventing dementia.

The Lancet article highlights the importance of treating hearing loss for possibly preventing dementia. If you’re interested in dementia, know someone with dementia, or want to see what you can do to avoid developing dementia yourself, I recommend the Lancet article. It summarizes a large body of research in a readable fashion that should be accessible even to the lay reader.

There are many factors correlated with dementia risk, including genes, blood lipid levels, and diseases or conditions such as diabetes, hypertension, obesity, and factors such as social isolation and cigarette smoking. The association between hearing loss and dementia is well-known and research is under way to see if treating hearing loss reduces the risk of dementia. Despite only correlations, and no clear understanding of how hearing loss may increase the risk, the Lancet authors think the scientific evidence is strong enough to recommend treatment of hearing loss as a possible prevention measure for dementia.

Of course, the only treatment for hearing loss is hearing aids, with cochlear implants reserved for the more severely impaired. We think that people with hearing loss should use hearing aids just to be able to hear others, whether hearing aids prevent dementia or not.

That said, hearing aids are a poor substitute for preserved natural hearing.

Perhaps the Lancet article should have gone a step further and highlighted the importance of preventing noise-induced hearing loss (NIHL) to delay or avoid the onset of dementia. After all, we think it’s significantly better to prevent NIHL than to treat it, and that’s simple: avoid exposure to loud noise or wear ear protection when you cannot.

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.

Attention parents-to-be: your baby can hear in utero!

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

Zayan Guedim, Edgy Labs, writes about a University of Kansas study that has determined that “[n]ot only can babies hear in utero…they [actually] start developing language sensitivity while in the womb.” Guedim notes that hearing is “the acutest sense of the fetus,” which can start to perceive sounds even before “the auditory cortex is fully developed.” By 16 weeks, “the fetal sense of hearing begins.” At first the fetus can perceive sounds but it cannot interpret them, but that changes from week 23, when “the fetus will hear ‘sounds’ to which it reacts by movement, accelerated heart rate or turning its head.”  What kind of sounds get the fetus’ attention? “High-pitched sounds, like a barking dog or a horn, will get the baby’s attention more than, say, soft background music.”

So, how sophisticated is a fetus’s sense of hearing? Guedim writes that “[i]t’s already established that newborns get familiarized with their parents’ native language and react differently to foreign languages.” But now, research by the University of Kansas Department of Linguistics suggests that “the fetus can distinguish between different languages” and will show “an inclination to the language they would acquire after birth–the one they’re used to hear during gestation.”

The study also confirms that “the baby reacts to the mother’s voice more than anything else, because “[u]nlike other voices and sounds that travel through the air, the mother’s voice reverberates through her bones and internal tissues that act as amplifiers.”

So mothers-to-be, speak clearly because someone is most assuredly listening in.