Jeanine Barone, writing for Principa-Scientific International, interviews Arline Bronzaft, PhD, asking Dr. Bronzaft about her lifetime of fighting noise. Dr. Bronzaft, an environmental psychologist, is a professor emerita of psychology at Lehman College, City University of New York, and an expert witness in court cases and government hearings on the impact of noise on mental and physical well-being. She also is a founding member of The Quiet Coalition.
Barone wonders whether noise has to be loud to affect people, to which Dr. Bronzaft responds that noise doesn’t necessarily have to be loud to affect someone because “[n]oise is any unwanted, uncontrollable, or unpredictable sound.” Dr. Bronzaft describes the negative effects of noise on health and quality of life, including its impact on children’s learning.
That noise is understood to be detrimental to children’s learning is due in large part to Dr. Bronzaft’s landmark study of an elementary school adjacent to an elevated train track in New York City. On one side of the building “the classrooms were exposed to passing train noise every 4.5 minutes,” while on the other side of the building “the classrooms were not intruded upon by passing train noise.” Dr. Bronzaft’s study showed that “[b]y the sixth grade, the children exposed to noise were nearly a year behind in reading.”
But Dr. Bronzaft didn’t conclude her study and move on. Rather, she brought the data to the transit authority and convinced them to employ noise suppression technology on the nearby tracks. Some years later she did a follow-up study that found that the noise had decreased and “children on both sides of the school were reading at the same level.”
Click the link to learn more about Dr. Bronzaft’s work
Doctors say kids are at higher risk for hearing loss. Dr. Rachel Wood, an audiologist with the LSU Health and Sciences Center, studies and treats hearing loss patients, and increasingly she is seeing younger patients. Dr. Wood says that there are a “growing number of factors that cause hearing loss.” One particular concern is that “[c]hildren especially can plug into their phone and crank up the volume, turn up the sound effects on video games, or even watch rock concerts on their computers.”
Dr. Wood finds headphones to be “especially troubling,” stating:
There are tiny sensors in your inner ear that are very sensitive. Loud sounds damage those sensors, and if they’re destroyed, they will never grow back, which leads to hearing loss. The amount of damage is based on the volume of the sound and how close the sound is to your ear. Since headphones put the sound right next to those sensors, it magnifies the damage.
So what can you do to protect your child’s hearing? Dr. Wood suggests that parents set volume limits on electronic devices such as phones. She also advises parents to impose time limits for using headphones and have their children take a break every 30 to 60 minutes. Finally, if your children are going to events with loud noises, such as concerts or fireworks displays, hand them a pair of ear plugs. Purchased in bulk, ear plugs are a cheap and easy way to protect your children’s hearing.
From the book The Human Body and Health Revised by Alvin Davison, 1908 / Public Domain
And Experts Say Earphones Are Part Of The Problem. Lori Mack, WNPR, reports on hearing experts’ growing concern about the potential health hazard earbuds and headphones pose to children. Mack states that “[s]tudies show hearing loss among kids and teens is up about 30 percent higher than it was in the ’80s and ’90s,” adding that “[e]xperts believe earphones are part of the problem.” A problem that turns on volume and time exposure. Simply put, the louder the sound, the less time it takes to damage your hearing.
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.
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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.
A new analysis on “the best kids’ headphones” by The Wirecutter, a product recommendations website owned by The New York Times, as reported in the New York Times science section, found that headphones marketed as “safe” for children’s hearing were louder than advertised. The Times’ article did not adequately reflect the extensive and thoughtful analysis by The Wirecutter’s reviewers, Lauren Dragan and Brent Butterworth. Their review deserves to be read (and reread) in its entirety, as it is without doubt the most complete and scientifically sound review about any noise topic that I have seen in the popular media.
The Wirecutter review mentions that two problems with headphones marketed as “safe for children”: (1) that the headphones are louder than they claim to be, and (2) that manufacturers are using an industrial-strength occupational noise exposure level as a safe noise level for children. The review doesn’t emphasize the latter point enough.
I discuss the origin of the 85 decibel noise exposure standard in detail in an editorial in the January 2017 issue of The American Journal of Public Health. The 85 decibel volume level at issue was developed by the National Institute for Occupational Safety and Health (NIOSH) to protect workers’ hearing. It comes with strict time limits–an 8-hour day, 240 days a year, for a 40-year work career–and even then does not protect all workers from hearing loss. NIOSH discussed the difference between an occupational noise standard and a safe noise level for the public earlier this year in a blog post titled, “Understanding Noise Exposure Limits: Occupational vs. General Environmental Noise.” The NIOSH post makes it very clear that 85 decibels is not a safe noise level for the public, and it certainly is not safe for toddlers or children who may be listening to music or watching videos for more than 7 hours a day, every day. In addition, children, and especially teens, are exposed to other loud noise sources–action movies, sports event, etc.–so their total noise dose likely approaches dangerous levels.
Children’s ears may be more sensitive to noise than adult ears. First, there is no doubt that an 85 decibel headphone speaker is closer to a child’s eardrum because the external auditory canal is shorter in children than adults. (Noise follows the inverse square law, so the closer a noise source is to the ear the louder it is.) Second, it’s unlikely that children will limit their listening to just 240 days a year, on average they will live for almost 80 years, and in the course of their lifetimes they will undoubtedly be exposed to more noise, in gyms, parties, rock concerts, sports events, and the like. A child’s delicate ears have to last her a whole lifetime.
Studies of auditory acuity in so-called primitive populations show that significant hearing loss in old age is not inevitable. These studies are not available online, so I can’t provide links, but the classic studies were done in the 1960’s by Rosen and colleagues in the Mabaan population in the Sudan, and by Dickson and colleagues in the Kalahari Bushmen. Rosen found that the Mabaan could carry on a conversation at normal speech volumes while facing away from each other at a distance of 100 yards. Dickson wrote that the Bushmen could hear an airplane 70 miles away. As noted in The Wirecutter review, acute hearing was a matter of life or death for our primitive ancestors, either to find food or to avoid being a predator’s meal. The Rosen and Dickson studies suggest that hearing loss so commonly seen in the U.S. is likely not part of normal part of normal physiological aging, but rather is noise-induced hearing loss–i.e., the result of a lifetime’s exposure to excessive noise. If one starts listening to 85 decibel sound at age 3, hearing loss and hearing aids may be inevitable–and at an earlier age than in the past.
What can be done to protect children’s hearing from dangerous consumer products marketed to them? The federal agencies charged with protecting the public should do their jobs. The Federal Trade Commission should take enforcement action on the grounds of false advertising against vendors claiming that headphones with the 85 decibel volume limit are safe for children. They may be safer than headphones without a volume limit, but they are by no means safe, especially without recommendations for time limits on use. The Consumer Product Safety Commission should require warning labels on headphones, earbuds, and personal music players, stating “LOUD MUSIC CAUSES DEAFNESS!” The pediatric community should do more to educate parents about the dangers of noise for children. And parents must step up and demand truly safe products for their children or deny their children access to products that will destroy their hearing.
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.
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.
Read this fascinating piece by Olga Khazan about researchers who found that children who lived on lower floors in a high-rise building near a highway in Manhattan had a harder time distinguishing words than kids living on higher floors and they were worse at reading. Frighteningly, “[t]he relationship between the kids’ scores and floor level was strongest for the kids who had lived in the building the longest.”
Noise is more than an annoyance when it can interfere with learning.
Why would someone want quiet fireworks, you may ask? Pet owners know that cats and particularly dogs can be adversely affected by fireworks, but humans are at risk as well:
For people, loud fireworks can lead to hearing loss. The World Health Organization lists 120 decibels as the pain threshold for sound, including sharp sounds such as thunderclaps. Fireworks are louder than that.
Dr. Williams also sees higher traffic to his clinic after Independence Day. “We usually see a handful of people every year,” he said. “In these cases, hearing loss is more likely to be permanent.”
And Dr. Williams added that children are more vulnerable to hearing loss from fireworks because they have more sensitive hearing. So if you are going to a fireworks display this weekend, enjoy it safely and bring ear plugs for the whole family.