Nav: Home

Today's teenagers could become prematurely hearing-impaired, study warns

July 12, 2016

Teenagers are increasingly experiencing tinnitus, often a symptom of hearing loss, as a result of using ear buds to listen to music for long periods every day, as well as frequenting very noisy places like nightclubs, discos and rock concerts, according to a study performed in Brazil.

Tinnitus is the medical term for perception of sound that has no external source. Many sufferers describe it as a ringing in the ears, others as whistling, buzzing, chirping or hissing. A paper describing the study has just been published in Scientific Reports, an online journal published by Springer Nature.

"We found a very high prevalence of tinnitus among adolescents, and this should be seen as an early warning that these youngsters run a serious risk of hearing loss. If this teen generation continue to expose themselves to very high noise levels, they'll probably suffer from hearing loss by the time they're 30 or 40," said Tanit Ganz Sanchez, associate professor of otolaryngology at the University of São Paulo's Medical School (FM-USP) and principal investigator for the study.

The researchers used an otoscope to examine the ears of 170 students between 11 and 17 years old. They also asked the teenagers to complete a questionnaire asking whether they had experienced tinnitus in the previous 12 months and, if so, with what volume, duration and frequency. Over half (54.7%) reported a prior experience of tinnitus.

"This level of prevalence is alarming," Sanchez said. "There was a notion that tinnitus was a problem of older people, but we're seeing it becoming more prevalent in younger groups, including children and teenagers, because of their increasing exposure to high levels of noise, among other factors."

The adolescents who reported prior tinnitus were submitted to psychoacoustic examination to assess hearing function. Administered by an audiologist in an acoustic chamber, the examination measured hearing thresholds using an audiometer at 14?frequencies (0.25-16?kHz), as well as loudness discomfort and the intensity of any tinnitus experienced.

During the psychoacoustic measurements, 28.8% of the total sample (49 out of 170) perceived tinnitus in the acoustic booth. The psychoacoustic properties of tinnitus measured in the sound booth corresponded with those of chronic tinnitus in adults.

"We found that adolescents perceive tinnitus very often but unlike adults don't worry about it and don't complain to parents or teachers, for example. As a result, they aren't seen by a doctor or hearing specialist, and the problem can become chronic," Sanchez said.

The researchers also observed that most of the teenagers who took part in the study reported risky listening habits, such as continuous use of ear buds and exposure to very noisy environments; even so, those who reported experiencing tinnitus displayed less tolerance of loud sounds.

Of the 93 school students who reported tinnitus in the last 12 months (54.7% of the total sample), 51 (54.8% of this group) said they had noticed it after listening to loud music. "If the ears of teenagers with tinnitus are more sensitive to high levels of sound than those without, it's natural to expect them to suffer from hearing loss sooner. The tinnitus is an early sign of this impairment that appears well before any actual hearing loss," Sanchez said.

Tinnitus is caused by temporary or permanent damage to cochlear hair cells. Located in the inner ear (cochlea), these cells stretch and contract repeatedly in response to sound-induced vibrations.

When they are stimulated by very loud noise, such as explosions, fireworks, live pop music, or music listened to through ear buds with the sound turned up, the cochlear hair cells are overloaded and can be temporarily or permanently damaged.

Neighboring regions of the inner ear must work harder and faster to compensate for the loss of function in damaged or dead hair cells, giving rise to tinnitus, Sanchez explained.

The results of recent animal experiments conducted by neuroscientists suggest that tinnitus can also be due to impairment of hair cell synapses (neural pathways) to the cochlear nerve, resulting in reduced neural output from the ear to the brain.

Damage to these synapses due to exposure to high levels of noise can cause not only hearing loss but also neural alterations in auditory pathways that reduce a teenager's sound level tolerance.

"The tinnitus and reduced sound level tolerance observed in the adolescents who took part in the study may be a sign of damage to hair cell synapses that isn't detected by an audiometric examination," Sanchez said. "For this reason, it may appear to be the case that there's no damage to the auditory pathway, but actually the damage doesn't show up in the audiometric data and this makes diagnosis difficult."

If these teenagers continue to use ear buds frequently and are exposed to very noisy environments until age 20 or 25, for example, the damage to their cochlear hair cell synapses will progress and they may become deaf while still relatively young, according to Sanchez.
-end-


Fundação de Amparo à Pesquisa do Estado de São Paulo

Related Hearing Loss Articles:

Victorian child hearing-loss databank to go global
A unique databank that profiles children with hearing loss will help researchers globally understand why some children adapt and thrive, while others struggle.
Hearing loss, dementia risk in population of Taiwan
A population-based study using data from the National Health Insurance Research Database of Taiwan suggests hearing loss is associated with risk of dementia.
Mice reveal 38 new genes involved in hearing loss
Multiple new genes involved in hearing loss have been revealed in a large study of mouse mutants by researchers from the Wellcome Sanger Institute, King's College London, and colleagues.
New contributor to age-related hearing loss identified
Researchers have discovered a new potential contributor to age-related hearing loss, a finding that could help doctors identify people at risk and better treat the condition.
Exploring the connection between hearing loss and cognitive decline
A new study led by investigators at Brigham and Women's Hospital adds to a growing body of evidence that hearing loss is associated with higher risk of cognitive decline.
Signs of memory problems could be symptoms of hearing loss instead
Older adults concerned about displaying early symptoms of Alzheimer's disease should also consider a hearing check-up, suggest recent findings.
Hearing loss is a risk factor for premature death
A new study links hearing loss with an increased risk for mortality before the age of 75 due to cardiovascular disease.
Study points to possible new therapy for hearing loss
Researchers have taken an important step toward what may become a new approach to restore the hearing loss.
Are portable music players associated with hearing loss in children?
The effect of portable music players on the hearing of children is unclear.
New study shows hope for hearing loss
USC and Harvard scientists found a new way to fix cells deep inside the ear, which could help millions of people who suffer hearing loss.
More Hearing Loss News and Hearing Loss Current Events

Best Science Podcasts 2019

We have hand picked the best science podcasts for 2019. Sit back and enjoy new science podcasts updated daily from your favorite science news services and scientists.
Now Playing: TED Radio Hour

Rethinking Anger
Anger is universal and complex: it can be quiet, festering, justified, vengeful, and destructive. This hour, TED speakers explore the many sides of anger, why we need it, and who's allowed to feel it. Guests include psychologists Ryan Martin and Russell Kolts, writer Soraya Chemaly, former talk radio host Lisa Fritsch, and business professor Dan Moshavi.
Now Playing: Science for the People

#538 Nobels and Astrophysics
This week we start with this year's physics Nobel Prize awarded to Jim Peebles, Michel Mayor, and Didier Queloz and finish with a discussion of the Nobel Prizes as a way to award and highlight important science. Are they still relevant? When science breakthroughs are built on the backs of hundreds -- and sometimes thousands -- of people's hard work, how do you pick just three to highlight? Join host Rachelle Saunders and astrophysicist, author, and science communicator Ethan Siegel for their chat about astrophysics and Nobel Prizes.