Listen Up! Childhood Noise Exposure and Hearing Loss

Exposure to loud noise is a common cause of hearing loss. When we think of noise-induced hearing loss (NIHL) we often think of very loud noises with long term exposures in adults; like a near-deaf ex-rocker who played way too many concerts in front of the amplifier, or the construction worker who regularly operates a jackhammer on the job. But there is increasing evidence that childhood noise exposures may be associated with early hearing loss. This should get parents to prick up their ears and pay attention!

What exactly is noise-induced hearing loss?
NIHL is a well-documented phenomenon that results from damage to the delicate “hair cells” in the cochlea that convert sounds from the outside world into signals to the brain. When that signal reaches the brain, it registers as noise. With repeated loud noise exposure over time, damage to the hair cells becomes irreversible. This is how noise-induced hearing loss works.

Can kids get NIHL?
Studies from 1988-2004 found that as many as 15% of kids in the U.S. ages 6-19 have some level of hearing loss. In 2006, this number was reported to have risen to 20%. That means almost 1 in 5 kids in America has a measurable amount of hearing loss. Kids and parents alike may not always notice these changes immediately, but these studies provide evidence that measurable levels of hearing loss are occurring in a large number of children at a very early age.

What are the implications of hearing loss in childhood?
Normal hearing during childhood is incredibly important, and reduced hearing at an early age can have a profound impact on your child. Even mild hearing loss in young children can impair speech and language development significantly. This can often lead to decreased educational achievement and even contribute to impaired social and emotional development.

How can I tell if my child is having hearing loss?
If you are worried that your child may have hearing loss, you should speak with your child’s doctor about your concerns. The doctor may want to perform a hearing exam in the office or may order testing with a hearing specialist with audiometry.

How can I reduce the risk of noise-induced hearing loss in my child?
Unfortunately, loud noises are all around us. While it is important to be vigilant about how much noise your children are being exposed to, there is no way to completely eliminate loud noise exposures. However, one commonly identified source of repeated loud noise exposure that is likely contributing to the rise in noise-induced hearing loss among kids is personal media devices such as I-Pods and cellular phones. Children have increasing access to these devices and often use earphones to listen to music or play games. Cutting back on the amount of “earphone time” and having your child take earphone breaks every 15-20 minutes may reduce their risk. Also, pay attention to the volume level. You may be able to significantly reduce your child’s loud noise exposure by having them turn down the volume.

How loud is too loud?
The exact level of noise that can cause hearing damage is variable. Noise-induced hearing loss often results from loud noise exposure over a period of time. Therefore, long exposures at lower noise levels may wreak as much havoc as shorter exposures to louder noises. Kids should not be exposed to noise levels above 85 decibels for prolonged periods. The higher the decibel range, the louder the noise, and the more likely it is to cause damage to the cochlear hair cells resulting in hearing loss.

References:
1. RV Harrison. Noise-induced hearing loss in children: A ‘less than silent’ environmental danger. Paediatr Child Health 2008;13(5):377-382.
2. Niskar AS, Kieszak SM, Holmes AE, Esteban E, Rubin C, Brody DJ. Estimated prevalence of noise induced threshold shifts among children 6 to 19 years of age: The third National Health and Nutrition Examination Survey, 1998-1994, United States. Pediatrics 2001;108:40-3.
3. Blair J, Peterson ME, Viehweg SH. The effects of mild sensorineural hearing loss on academic performance of young school-age children. Volta Review.
1985;87:87-93.

May 2015. This post was authored by Zachary Crees, University of Illinois medical student and Susan Buchanan, MD, MPH, Director of the Great Lakes Center for Children’s Environmental Health – Region 5 Pediatric Environmental Health Specialty Unit (PEHSU).

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