Hearing protection

An explainer on noise cancelling headphones:

How do noise cancelling headphones work? Royce Wilson, news.com.au, writes about noise cancelling headphones, the cure-all to our modern noisy world.  But have you ever wondered how they actually work?  Wilson reports that there are “two types of noise cancelling technologies for headphones — passive and active,” and he asked University of Queensland School of Information Technology and Electrical Engineering research fellow and lecturer Dr Konstanty Bialkowski about the different approaches.  Dr. Bialkowski said that the passive technology is “like having a cup around your ear that reduces high-frequency noise” (“people talking or high-pitched squealing”), while active cancellation is for low-frequency noise (e.g., low-pitched hum like a car engine, aeroplane engine or a fan).  With active cancellation, the headset, which has a microphone, “knows the distance between the microphone and your ear and it makes [a] complete opposite noise” to cancel out the distracting noise.

Click the link for the full article, which includes a review of the Sony’s MDR-1000X wireless noise cancelling headphones.

 

University of Kansas “wins” title for loudest crowd roar at an indoor sports arena

by Daniel Fink, MD

Maybe one day the Guinness Book of World Records will have a category for the most people sustaining auditory damage at one time at an indoor sports event? Because that’s what happened in Lawrence, Kansas, at the University of Kansas’ Allen Fieldhouse on February 13, 2017. A new world record was set for indoor noise at a sports event: 130.4 decibels. The previous “winner,” the University of Kentucky’s Rupp Arena, set a record of 126.4 decibels just two weeks earlier.

It was a great game, undoubtedly sold out. Kansas won in overtime, coming back from a 67-60 deficit with 1:13 to play in regulation to tie the game, and then won in overtime. The few disheartened fans who left early missed the conclusion of a one of the season’s best basketball games. Famed Kansas coach Bill Self called it “the most remarkable win I’ve ever been a part of.” But his ears, the players’ ears, the ears of team and fieldhouse staff, and those of the capacity crowd of 16,300, undoubtedly also suffered permanent auditory damage. That’s because 130.4 decibels is about as loud as a four-engine jet plane from 100 feet away, but the auditory injury threshold (the point at which a hearing injury may occur) is only 75 to 78 decibels.

Maybe one day the NCAA, which touts “Student-Athlete Well-Being” as one of its core principles, will show some concern for the auditory health of its student-athletes and ban this type of silly and dangerous competition at NCAA events.

But if not, then how about a contest to see how many NCAA student athletes and sports event attendees can be blinded at one time by the host NCAA institution shining powerful laser lights into the stands and team benches at the sports arena?  Hey, a world record is a world record, right?

Or maybe reason will prevail and the people who have the power to stop this senseless and dangerous contest will come to their senses?  They can’t say that they didn’t have notice, because my letter to the editor of The Kansas City Star was published on Monday, February 20th.  Your move, NCAA.

Dr. 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 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.

Hearing Loss Is Growing


From the book The Human Body and Health Revised by Alvin Davison, 1908 / Public Domain

And Experts Say Earphones Are Part Of The Problem.

Mack interviews audiologist Michele Abrams who spoke about limiting exposure to damaging sound:

When we think about decibel levels, when we think of loudness levels, it’s really incremental.  It’s a logarithmic scale. It’s not a linear scale. So we know that 85 db is that critical level. Eighty-five db, eight hours a day, that’s your maximum. If it’s 90 db — five db greater — you have to cut your time in half.

While generally informative, Abrams’ comment unfortunately identifies 85 db, eight hours a day as the “critical level.”  But this noise exposure level is too high.  It was developed solely as an occupational noise exposure standard and should never be applied to the general public, certainly not to children.  As Dr. Daniel Fink, a noted noise activist, wrote in, “What Is A Safe Noise Level For The Public?”:

In the absence of a federal standard, an occupational standard meant to prevent hearing loss appears to have become the de facto safe level for all public noise exposures. This is demonstrated by the use of 85 decibels as a safe sound level by hearing health professionals and their organizations, in media reports, and in publications, most often without time limits; by its use as a volume limit for children’s headphones marketed to prevent hearing loss, again without exposure times; and by general acceptance of higher indoor and outdoor noise levels in the United States.

*   *   *
Eighty-five decibels is not a safe noise exposure level for the public. In 1972, the National Institute for Occupational Safety and Health developed an 85 A-weighted decibel recommended exposure level to reduce the risk of hearing loss from occupational noise exposure. … Even with strict time limits, this standard does not protect all workers from hearing loss.

So what is a safe noise level for the public?  Dr. Fink states:

In 1974 the Environmental Protection Agency’s (EPA’s) Office of Noise Abatement and Control (ONAC) adjusted the National Institute for Occupational Safety and Health recommendation for additional exposure time: 24 instead of 8 hours daily and 365 instead of 240 days annually.  The EPA calculated the safe noise level for the public to prevent hearing loss to be a 70-decibel time-weighted average for a 24-hour period… The EPA did not adjust for lifetime noise exposure, now almost 80 years versus 40 work-years, so the real average safe noise level to prevent hearing loss is probably lower.

One thing is clear, allowing children to use earbuds or headphones without limiting volume and time exposure is a recipe for hearing loss.  Since the federal government has abdicated its authority to regulate noise, and manufacturers are unlikely to design products that limit the user’s ability to deliver as many decibels as he or she wants, parents must step in to protect their children’s hearing.  Here’s something that will help: Don’t allow your children to wear earbuds and headphones.  Tell them that if they want to listen to music they must play it through a speaker.  While this may be unpopular, know that you will be giving your children an important gift–the ability to listen to and enjoy music throughout their lifetimes.

 

 

If he thinks the UK is loud, he should (not) visit the U.S.:

Photo credit: Quiet City Maps

“I wear earplugs everywhere because Britain is too loud.”  Katie Morley, The Telegraph, reports that the UK’s “most famous choirmaster, Gareth Malone, has revealed that he wears earplugs everywhere he goes because Britain has become too noisy.”  Malone wears earplugs all the time because “ears are the tools of my trade and I don’t want to do anything to endanger them.”  Morley writes that despite Malone’s belief that he is “‘geeky’ for protecting his ears from loud sounds, Mr Malone may well be in common with an emerging breed of people who class themselves as intolerant to so-called ‘noise pollution.'”

She almost had us until her use of the unnecessary “so-called.”  Interestingly, while relying on that weasel word to modify the term “noise pollution,” the rest of the piece highlights the many ways in which noise has overwhelmed the UK and damaged the quality of life of a majority of Brits.  Sounds a bit melodramatic, but Morley writes that “two thirds of UK homeowners say their lives are being blighted by noisy activities of their next door neighbours.”

Click the link for the full story.

This is fascinating:

crash-photo

Mercedes-Benz E-Class will blast pink noise at you just before an accident, to protect your ears.  That’s right, in an effort to cut down on “hearing damage caused by the deafening crunch of a car crash,” Mercedes-Benz is going to “blast[] pink noise through the stereo when you’re about to hit something.”  What will the pink noise do?  It will “trigger a fascinating physical response…known as the acoustic reflex, or stapedius reflex – an involuntary muscle contraction in the middle ear that effectively dampens the vibrational energy that’s transferred to the cochlea.”  Essentially, the reflex action will reflect some of the noise from a crash back through the ear drum, thus avoiding the inner ear.  Click the link to learn more.

 

 

 

Why were Prince George and Boomer Phelps photographed wearing ear muff hearing protectors?

No doubt you’ve seen the photos of Prince George and Boomer Phelps wearing ear muff hearing protectors.  Did you ask yourself why?  Daniel Fink, M.D., a leading noise activist, explains:

These little boys aren’t working in noisy factories. They aren’t going to the shooting range.  They aren’t going to a rock concert.  They are just doing things that normal little boys like to do, going to an air show or watching daddy swim.  But Prince George’s parents and Boomer’s parents know one important thing: NOISE CAUSES DEAFNESS.

Dr. Fink states that the places and events parents bring their children to–whether by choice or circumstance–are often loud enough to damage hearing permanently.  Unlike British royalty or Olympic athletes, most parents simply don’t know that their children could suffer permanent hearing damage by being in a loud place with no hearing protection.  Dr. Fink believes that the lack of warnings highlights a general failure by the medical community, which should be advising parents to protect their children’s hearing.  He notes that respected online parenting resources make no general recommendations about protecting children from noise, mentioning only the dangers of infant sound machines for babies and loud music for teens.

It’s not just the medical community that is failing children.  Federal and state governments do little to inform citizens of the danger loud noise poses to health or to protect them from noise exposure.  There is very little regulation of noise in public spaces and absolutely no oversight of consumer products that can damage hearing.

Dr. Fink states that “there is an increase in hearing loss in young people, perhaps because parents don’t know the dangers of noise for hearing.”  He notes that race cars produce sound up to 130 decibels, air shows can produce sound up to 130 decibels, rock music concerts can reach 110-115 decibels, action movies range between 100-125 decibels, and sporting events can be loud, too, at 100-120 decibels.

Children can also be exposed to loud noise at home.  Personal listening devices can reach up to 115 decibels, a sound level that is guaranteed to damage hearing if exposure is more than a few minutes, and yet there is no government mandated warning for the purchasing public.  In addition, there are headphones marketed specifically for children that use a 85 dBA occupational noise exposure limit as a volume limit to prevent hearing loss.  “The commonly cited safe noise level of 85 decibels is really an industrial-strength occupational noise level developed by the National Institute for Occupational Safety and Health for workers,” says Dr. Fink.  He adds that “even with strict time limits of noise exposure, some workers exposed to this noise level will develop hearing loss.  One thing is for sure: 85 decibels is not a safe environmental noise exposure level for the public and certainly not for children.”

And Dr. Fink has an impressive ally in his fight against the misuse of the 85 decibel industrial-strength standard.  In May 2016 , the U.S. Centers for Disease Control and Prevention (CDC) posted content addressing Environmental Noise Exposure and Health, in which it stated that in 1974 the Environmental Protection Agency recommended that the average daily noise exposure be limited to an average of 70 decibels for a whole day, with no more than one hour at 85 decibels.  The CDC noted that World Health Organization also “recommend[ed] that noise exposure levels should not exceed 70 dB over a 24-hour period, and 85 dB over 1 hour period to avoid hearing impairment.”

So what can you do to protect your children’s hearing?  Treat noise like you treat sun exposure.  When you take your child to the beach, you protect his or her eyes and skin by giving them sunglasses, a hat, and by applying sunscreen.  If noise caused vision loss instead of hearing loss, everyone would be more vigilant in addressing it.  So apply the same degree of vigilance when your child will be exposed to noise as you would when your child is exposed to full sun.  Dr. Fink advises that the best thing a parent can do is to not bring a child, at whatever age, to loud events.  “If that can’t be avoided,” he cautions, “then at the least protect your child’s hearing with ear muff style hearing protectors.”  That is, follow what Prince George’s parents and Boomer Phelps’ parents do.  Dr. Fink, a father of two, adds that, “the best way to make sure your kids do something is for you to model the behavior yourself.  If it’s loud enough for your children to be wearing hearing protection, you should be wearing it too.”

 

 

What is America’s most common workplace injury?

Hearing loss.  Zhai Yun Tan, Kaiser Health News, writing for PBS News Hour, examines hearing loss, which the Centers for Disease Control and Prevention has identified as “the most common work-related injury with approximately 22 million workers exposed annually to hazardous levels of occupational noise.”  ‘[I]n an effort to reduce these numbers,” she writes, “the Labor Department launched a challenge earlier this summer called ‘Hear and Now,’ in which it is soliciting pitches for innovative ideas and technology to better alert workers of hazardous noise levels.”

Critics have countered that technology to address the problem already exists.  The real problem, they claim, is that the maximum noise exposure level and Occupational Safety and Health Administration (OSHA) regulations are outdated.  Among other things, the OSHA regulations “use sound level limits that don’t factor in the noise exposures that occur beyond the workplace — at restaurants, concerts and sporting venues, for instance — that can add to workers’ cumulative risks of harm.”  OSHA officials offered that “the agency will issue a request for information later this year about current regulations at construction sites to figure out if more stringent protections are needed and how companies are complying,” but Tan notes that “[a] similar call for information was issued in 2002, but no changes resulted from the action.”

Tan suggests that employers will have to assume more responsibility in educating workers, as some workers do not use hearing protection at work because they are not aware of the risk.  Click the link above to learn more, including Tan’s report about Jeff Ammon, a former construction worker who can no longer work due to hearing loss and hyperacusis, a condition marked by sensitivity to environmental noise.

 

 

Important information for parents

Catherine Caruso, reporting for Scientific American, writes about “Detecting Hidden Hearing Loss in Young People.”  Caruso looks at hidden hearing loss, a phenomenon discovered in 2009, which the researchers who discovered it consider a “likely contributor to the cumulative loss typically associated with aging.”  Now, those researchers have developed tools for detecting hidden hearing loss and have discovered evidence of hidden hearing loss in young people.

While Caruso notes that there is hope that hidden hearing loss could be reversed in the future, she also points out steps one can take now to protect hearing: namely, by limiting noise exposure and using ear protection.  And parents, talk to your kids about their earbud and headphone use.  No one knows if and when researchers will be able to reverse hidden hearing loss, so avoiding hidden hearing loss in the first instance is the best tact.

Here’s some helpful advice for those who work in open-plan offices:

The best ways to cope with a noisy office.  Rachel Becker, writing for The Verge, is wisely concerned about finding a good option to block distracting noise at work that won’t put her hearing at risk.  Becker notes that “[h]earing loss typically occurs as people age” and that it is irreversible, but what she is concerned about is the World Health Organization’s statement that “more than 1.1 billion young adults are also at risk” of hearing loss because approximately “half of [all] people ages 12 to 35 in middle-to-high income countries are exposing themselves to unsafe levels of noise on their devices.”  That is, younger people are engaging in activities that almost guarantee they will suffer hearing loss as they age, something Becker wants to avoid.

Sadly, her review of options doesn’t reveal a perfect answer.  But her article is important because she is young and aware that she may be able to avoid hearing loss entirely by taking steps to protect her hearing today.  She’s right, after all, about hearing loss being irreversible, and the truth is that no one knows when, or if, a cure will be found.  Since noise-induced hearing loss is 100% preventable, Becker is choosing the wiser route: avoid exposing your ears to damaging sound today to preserve your hearing tomorrow.

 

Animals are responding to human noise:

Bats are adapting their hunting strategies to the noise of our cities.  The good news is that a study published in Science shows that bats appear to be successfully adapting to human noise.  But as a researcher not involved in that study notes, “[s]ome animals probably can’t [adapt].”  So what happens to them?  And what about humans?  As the world gets noisier, how will we cope?  Or not?  It’s certainly something that should be addressed sooner rather than later, because, as the article reports:

“This is way beyond bats now. This is about thinking about any animals,” says Paul Faure, the director of the Bat Lab at McMaster University, who was not involved in the study. “We are domesticating our planet, we’re creating noise pollution, we’re creating light pollution. We’re fundamentally altering the world that we live in.”

Noise and its effect on all animals, including humans, has been ignored for too long.  It’s more than just a nuisance.  Among other things, noise can damage hearing with one exposure.  It’s time that the federal, state, and local governments step up and regulate noise much as they regulate air or water pollution, treating noise as the public health hazard that it is.  It also is time for adults to assume some responsibility for their hearing and their children’s hearing by protecting themselves and others through the use of ear plugs and ear muff protectors, or by the simply lowering the volume when they can, and leaving a loud space when they cannot.  It’s time that we take noise-induced hearing loss and other noise-induced hearing injuries seriously.  Because until we do, people will continue to suffer permanent hearing injuries for which there is no cure, a particularly galling situation when one considers that noise-induced hearing injuries are 100% preventable.