Medical and scientific news

As if you needed another reason to ask for the music to be lowered:

Photo credit: Quiet City Maps

Photo credit: Quiet City Maps

Can Your Ears Help Control Your Stomach?  According to a recent study, it looks like the answer is yes:

In one paper, marketing professors at Brigham Young and Colorado State universities asked 71 volunteers to eat a snack of pretzels while wearing over-the-ear headphones. Some volunteers were subjected to loud white noise from the headsets as they ate, while a second group heard quieter noise.

The result? Those listening to the loud noise consumed 49% more pretzels than those listening to the quieter noise. The findings suggest, according to the researchers, that the sound you make while eating is an important cue to how much you’re taking in. Listening to loud noise evidently made it harder to know when to stop, implying that dieters might want to turn down the music while dining.

Interestingly, the paper was the work of marketing professors.  No doubt the findings will be used by restaurant owners to crank up the volume even higher.

 

Yet another reason to ban electric hand dryers:

Dyson Airblades ‘spread germs 1,300 times more than paper towels’.  That said, the study only looked at Dyson Airblades and not other electric hand dryers, like the Xcelerator, which may spread viruses more effectively while assaulting your hearing.  Use a paper towel.

Thanks to Hyperacusis Research Limited for the link.  Hyperacusis Research Limited is a non-profit charity dedicated to funding research on what causes hyperacusis with the goal of developing effective treatment.

The Philly Voice asks:

How do earbuds damage your hearing?

Philly Voice reporter Brandon Baker posed this question Linda Ronis-Kass, an audiologist at Penn Medicine Washington Square, “for an explanation of how listening to music at a high volume through earbuds can cause hearing loss — and potentially more.”  It’s an interesting read, particularly for those of you who like to pop in your earbuds and crank the volume up (don’t!!).

Thanks to Hearing Health Foundation for the link.

You’ve been told that you should wear ear plugs to concerts, now you will know exactly why:

Why you should wear earplugs to concerts.  And the reason is that a research study has proven that ear plug use protects hearing:

[R]esearchers from the Netherlands randomly assigned 51 people, with an average age of 27, attending an outdoor music festival in Amsterdam into two groups: one in which the participants wore ear plugs and another where they did not. The subjects, who were advised to avoid excessive use of alcohol or drugs, had their hearing evaluated right before and immediately after the four-and-a-half hour festival.

* * *

The study found that only 8 percent of people who wore earplugs experienced hearing loss following this exposure, compared with 42 percent of those in the unprotected group. Additionally, fewer participants wearing earplugs felt a ringing in their ears — a condition known as tinnitus — following the festival, compared to those who did not wear earplugs (12 percent versus 40 percent).

The findings are important, the authors say, as repeated instances of loud music exposure can add up to longterm damage.

Hearing damage is cumulative.  Each exposure to loud noise that results in “temporary” hearing loss or ringing in one’s ears may seem limited in time, but each exposure builds on the last and can lead to permanent and irreversible hearing loss.  You only have one set of ears and science has not discovered how to regrow, rejuvenate, or replace the stereocilia that allow you to hear.  Next time you head to a concert or music festival, get a pair of ear plugs and protect your hearing.

NOTE: The statement in the article that “85 dBA is considered the cut off between safe and potentially unsafe loudness levels” is not correct when applied to the general public.  In February 2016, the National Institute for Occupational Safety and Health (NIOSH) posted an article on its Science Blog that stated that the 85 dBA noise exposure limit was intended as a limit for occupational noise exposure and not a safe exposure limit for the public at large.  See, NIOSH Science Blog clarifies difference between occupational and general noise exposure limits.

Thanks to Hyperacusis Research Limited for the link.  Hyperacusis Research Limited is a non-profit charity dedicated to funding research on what causes hyperacusis with the goal of developing effective treatment.

Ear buds are killing your ears

The Chicago Tribune published a very informative article on How earbuds can wreck your hearing (especially for young people).  The article notes that:

A 2015 World Health Organization report found that nearly 50 percent of teens and young adults ages 12-35 are exposed to unsafe levels of sound from their personal music players. A 2010 Journal of the American Medical Association analysis found a significant increase in young people with hearing loss from three decades ago.

It’s well worth a read, particularly for the advice provided on how to know when sound is too loud and what you can do to limit harmful exposure.

Thanks to Bryan Pollard for the link.  Bryan is the founder and president of Hyperacusis Research Limited, a non-profit charity dedicated to funding research on what causes hyperacusis with the goal of developing effective treatments.

World Health Organization: 1.1 billion young people worldwide face the risk of hearing loss

The American Council on Science and Health (ACSH) has posted an important article on hearing loss and young people: Millennials, the Deaf Generation?  The article states that a major cause of hearing injury to young people are music players, noting that the WHO “found that almost half of those ages 12 to 35 listen to their music players at unsafe volumes, while around 40 percent expose themselves to very loud events such as concerts.”  Among other things, the article suggests that using over the ear headphones over earbuds could help reduce the risk, especially when coupled with keeping the player’s volume at 60% of its range and listening to music for no more than 60 minutes at a time.

The concern about hearing loss in young people is also addressed by Shari Eberts, a hearing health advocate in her piece, “A Silent Epidemic. Teen and Young Adult Hearing Loss.”  Ms. Eberts writes that “[a] research study published in The Journal of American Medical Association in 2010 found that 1 in 5 teens had some type of hearing loss. This was significantly above the 1 in 7 teens with hearing loss measured 10 years earlier.”  She agrees that the use of earbuds is a significant cause for the alarming increase in hearing loss, but she adds that “the increased volume levels at restaurants, bars, sporting events, and other venues are also likely to blame.”  As someone who has genetic hearing loss Ms. Eberts knows firsthand about the frustration and sadness young people with hearing loss will suffer, noting that such suffering is avoidable since noise induced hearing loss is 100% preventable.  As in the ASCH article, Ms. Ebert recommends steps people can take to avoid hearing injury in the first instance.

This silent epidemic of hearing loss is not going to be silent for much longer.  One hopes that the increased attention on hearing loss among the young will motivate government, business, and individuals to work together to prevent the unnecessary deafening of an entire generation.

 

Maybe this will get peoples’ attention:

AC/DC’s Brian Johnson quits touring for good because of hearing loss.

Yes, nothing like the threat of complete hearing loss to bring home the importance of protecting one’s ears.  Let’s hope that AC/DC considers the damage inflicted on concert goers when they resume touring.

Safe noise exposure for the general public

Daniel Fink, M.D., Interim Chair of the Quiet Communities Health Advisory Council, has written a post for the Quiet Communities’s blog that tackles a question which is rarely addressed: What noise level IS safe for preventing hearing loss?

In his post, Dr. Fink discusses the seeming contradiction between a 1974 Environmental Protection Agency (EPA) determination that “a 24-hour average noise exposure level of 70 decibels (dB) or less prevent[s] measurable hearing loss over a lifetime” with statements from various governmental and nonprofit organizations that suggested that “a much louder noise level − anything up to 85 dB − was safe for our ears.”  In the course of researching the issue, he received a communication from the National Institute of Occupational Safety and Health (NIOSH) that explained where the 85 dB figure came from; the information in that communication formed the basis of a post on NIOSH’s Science Blog in February 2016 (which is discussed here).

Long and short, the NIOSH communication explained that the 85 dB was an occupational noise exposure standard developed to protect workers over a lifetime of work, whereas the EPA determination of 70 dB averaged noise exposure over 24 hours was believed to protect the general public from hearing loss over a lifetime.  As Dr. Fink notes that the clarification of the difference in noise exposure limits is important in setting public policy and protecting public health, and he concludes that, based on his research, “[t]he much lower 70 dB average noise exposure level is the only published safe noise level to protect the public’s hearing.”

 

NIOSH Science Blog clarifies difference between occupational and general noise exposure limits

Many people are confused about what is a safe noise limit for the general public because the only noise limit the public may have heard about is the 85 decibel recommended exposure limit (REL) that National Institute for Occupational Safety and Health (NIOSH) established for occupational noise exposures.  Fortunately, the NIOSH Science Blog has just posted an informative piece* that discusses acceptable RELS for both, titled: Understanding Noise Exposure Limits: Occupational vs. General Environmental Noise.

The authors state that in 1998, NIOSH established the REL for occupational noise exposure to be 85 decibels based on an 8-hour shift for a 5-day work week, adding that the REL “assumes that the individual spends the other 16 hours in the day, as well as weekends, in quieter conditions,” and cautioning that “the NIOSH REL is not a recommendation for noise exposures outside of the workplace in the general environment.”  The difference between the occupational and general environmental noise exposures is that:

The NIOSH REL is not meant to be used to protect against general environmental or recreational noise; it does not account for noisy activities or hobbies outside the workplace (such as hunting, power tool use, listening to music with ear buds, playing music, or attending sporting events, movies and concerts) which may increase the overall risk for hearing loss.

The authors point out that a 1974 Environmental Protection Agency (EPA) report recommended 70 decibels over a 24-hour average exposure limit for general environmental noise (while noting the EPA’s caution that its recommendation was not a standard, specification, or regulation).  This recommendation was determined in a similar manner as the NIOSH REL, but it’s focus was on general environmental noise and not the workplace.  As the EPA report states, their recommendation “was chosen to protect 96% of the general population from developing hearing loss as well as to protect ‘public health and welfare.’”

The authors note that both limits “are based on the same scientific evidence and the equal-energy rule,” but “are designed to protect against different problems.”  As a result, the limit values differ because “the EPA limit was averaged over 24 hours with no rest period while the NIOSH limit is averaged for just 8 hours and includes a rest period between exposures,” and the EPA limit includes an allowance “to protect against exposures for 365 days a year versus the NIOSH REL’s calculation that aims to protect against work place exposures for 250 working days a year.”   The authors add that “the EPA limit did not consider cost or feasibility of implementation as the Occupational Safety and Health Administration (OSHA), in accepting a NIOSH REL as the basis for a mandatory standard, [was] required to do under the Occupational Safety and Health Act of 1970.”

Long and short, the authors conclude that the 85 decibel REL is a work standard that neither mandates nor recommends decibel limits for the general public.  Rather, it is the EPA’s recommendation of 70 decibels that provides the appropriate exposure limits for the public with regard to general environmental noise.

*The post was prepared by NIOSH engineer, Chuck Kardous, MS, PE; NIOSH audiologist, Christa L. Themann, MA; NIOSH research audiologist Thais C. Morata, Ph.D., who is also the Coordinator of the NORA Manufacturing Sector Council; and W. Gregory Lotz, Ph.D, Captain, US Public Health Service, Division Director of the Division of Applied Research and Technology (DART), and the manager of the NORA Manufacturing Sector Council.

Turn It Down: How to protect yourself against noise pollution

In “Turn It Down,” Dangerstoppers (Beverly Hills Television) highlights the dangers of noise exposure and its adverse effect on hearing.  The video is very good at informing viewers about dangerous levels of sound and provides tips on how one can limit his or her exposure to noise pollution.  Included in this important piece is Dr. Daniel Fink’s segment on ear plug options for hearing protection.

Thanks to Daniel Fink, M.D., a noise pollution activist in the Los Angeles area, for the video link.  Dr. Fink serves on the board of the American Tinnitus Association.