Noise Hyper-Sensitivity in Kids

Although we mainly see kids for hearing loss due to fluid in the ears, chronic ear infections, or eustachian tube dysfunction, every so often, a child will show up with the exact opposite problem.

The child hears just fine, but suffers from noise hypersensitivity, also known as auditory hypersensitivity. Such children are overwhelmed from everyday noises whether doorbells, sirens, key clanking, etc; typically high-pitched sounds. The hands will go over the ears in an attempt to dampen the sound and may even become tearful.

This phenomenon is not uncommon in kids with developmental delays, autism, central auditory processing disorders (CAPD), Down's syndrome, etc. But "normal" kids may suffer from this condition as well.

Before going into treatment, one first needs to understand how sound is perceived first.

Human hearing is a complex listening device composed of not just the ability to "hear" the sound, but also to "comprehend" the sound. Disorders like CAPD is analogous to dyslexia where the patient can "hear" sounds perfectly normally, but has trouble understanding what they hear.

As a child develops, the auditory neural pathways in the brain that govern the comprehension of sounds are either reinforced or dampened down with time. For example, auditory neural pathways that allow for speech comprehension are reinforced whereas neural pathways perceiving background noises and other random sounds are dampened with time.

In auditory hypersensitivity, for whatever reason, the auditory neural pathways governing the perception of certain miscellaneous noise like sirens or doorbell are reinforced causing the perception of the sound to be more significant and tremendous than it should be. In a normal child without sensitivity, such pathways are suppressed.

To use an analogy, consider the auditory neural pathway like the road system in the United States. Over time, certain roads like the interstate highway is "reinforced" leading to more drivers using such streets to get from point A to point B far more quickly than if they used local roads. Problems occur if for some reason, cars avoid the highways and local roads are taken preferentially leading to traffic jams and irate drivers.

Auditory hypersensitivity is kind of like that... local roads being "reinforced" when it should be suppressed.

So what can be done to treat this frustrating condition?

In essence, therapy is geared towards reinforcing good auditory neural pathways and suppressing the bad ones that lead to noise hypersensitivity.

Such therapy programs include listening to special music and ear training exercises. One such program is "The Listening Program".

But one thing is clear... keeping someone with noise sensitivity in silence is the worst thing that can be done. It just reinforces the bad pathways!

Of course, there are other causes of noise sensitivity:

1) Migraines (children may not exhibit the class head pain, but they still can suffer from noise sensitivity)
2) Cochlear hydrops (if associated with hearing loss, tinnitus, sound distortion)

New Video on Newborn Hearing Testing

Given how often we see newborns in need of hearing testing, we have produced a video showing how the two main types of non-verbal hearing tests are performed today: Auditory Brainstem Response (ABR) and Otoacoustic Emission (OAE).

Given newborns can not communicate whether they can hear or not, such hearing tests depend on the ability to detect nerve signals transmitting sound information from the ear all the way to the brain. This type of test is much like an EKG which can detect the electrical activity of the heart.

Watch the video to see how ABR and OAE hearing testing works in infants (as well as adults)!

Toddlers Unable to Tell If They Mispronounce a Word (Thereby Can't Auto-Correct)

Older children and adults constantly monitor what they say and automatically correct or self-adjust when they hear a peach error... oops, sorry I meant to say "speech" error.

Such auditory feedback error correction however is not something we are born with. Rather it seems to be a skill that develops sometime between ages 2 and 4 years according to a new study.

"Researchers had adults, four-year-olds, and two-year-olds say “bed” repeatedly. But scientists filtered the sound so that the subjects heard themselves through headphones pronouncing it as “bad.” Adults spontaneously compensated, and changed so that the word sounded correct to their own ears. They wound up saying “bid.”

Four-year olds also adjusted their speech.

But the two-year olds kept saying “bed” even though they kept hearing “bad.”"

So, how do young children learn to speak correctly if they can't even hear themselves say something incorrectly?

The answer to this question has great import, especially to speech therapists whose job is to "fix" this problem. ENTs are often consulted as well to ensure a child does not have a tongue tie or hearing loss that can also lead to speech difficulties in a young child.

It's possible that young children depend on their parents to correct them when they say something incorrectly.

However, nobody quite knows for sure.

A follow-up study (not sure if will pass muster with an IRB) would be to have 2 sets of 2 year olds... one group where the parent constantly corrects any speech errors the child makes immediately. The other set would have parents NEVER correct a child's speech errors and let the child learn on their own.

Two possible outcomes... By the age of 5 years, there may be no difference in speech skills between the two groups OR there is a big difference and all the parental anxiety over their 3 years old child's inability to say "pizza" may be unnecessary (along with speech therapy sessions)... after all, they will "grow" or "learn" out of it with time.

Reference:
Toddlers Don't Monitor Their Own Speech. Scientific American 12/24/11

Children's Development of Self-Regulation in Speech Production. Current Biology, 10.1016/j.cub.2011.11.052