Evidence of hearing damage in teens prompts researchers' warning

In my neighborhood, it is the parents who subject their children to very loud music.

http://www.eurekalert.org/pub_releases/2016-06/mu-eoh060316.php

Public Release: 6-Jun-2016
Evidence of hearing damage in teens prompts researchers' warning
McMaster University

New research into the ringing-ear condition known as tinnitus points to an alarming level of early hearing damage in young people who are exposed to loud music, prompting a warning from a leading Canadian researcher in the field.

"It's a growing problem and I think it's going to get worse," says Larry Roberts of McMaster's Department of Psychology, Neuroscience and Behaviour, the only Canadian author of a paper published today in the journal Scientific Reports. "My personal view is that there is a major public health challenge coming down the road in terms of difficulties with hearing."

The researchers interviewed and performed detailed hearing tests on a group of 170 students between 11 and 17 years old, learning that almost all of them engage in "risky listening habits" - at parties, clubs and on personal listening devices - and that more than a quarter of them are already experiencing persistent tinnitus, a ringing or buzzing in the ears that more typically affects people over 50.

Further testing of the same subjects - all students at the same school in São Paulo, Brazil - showed that even though they could still hear as well as their peers, those experiencing tinnitus were more likely to have a significantly reduced tolerance for loud noise, which is considered a sign of hidden damage to the nerves that are used in processing sound, damage that can foretell serious hearing impairment later in life.

Roberts explained that when the auditory nerves are damaged, brain cells increase their sensitivity to their remaining inputs, which can make ordinary sounds seem louder. Increased loudness perception is an indication of nerve injury that cannot be detected by the audiogram, the standard clinical test for hearing ability. Neuroscience research indicates that such "hidden hearing loss" caused by exposure to loud sounds in the early years deepens over the life span, worsening one's hearing ability later in life.

"The levels of sound exposure that are quite commonplace in our environment, particularly among youth, appear to be sufficient to produce hidden cochlear injuries." says Roberts. "The message is, 'Protect your ears.'"

•••••