Possible causes and helpful remedies for hypersensitive hearing.

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Sound Sensitivity: A Summary of Possible Causes

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This article appeared in a previous issue of The Sound Connection,

1998, Vol. 5, No. 3, pages 1 & 2. The Sound Connection is the

quarterly newsletter of the Society for Auditory Intervention

Techniques (P.O. Box 4538, Salem, OR 97302, USA).

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(Forwarded from esmom.) originally forwarded from another source.

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Sound sensitivity has been discussed in previous issues of The Sound

Connection and is a topic of continuing interest since this problem

is experienced by many individuals who have developmental disorders.

It is also seen in some individuals as an isolated problem with no

other disabilities being present. This article will summarize

current information about causes. The causes of auditory sensitivity

can be classified into two categories: biochemical (which includes

nutritional deficiency and drug side-effects) and physiological.

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It is well established that nutritional effects may result in

hypersensitive hearing. Many individuals who are deficient in

magnesium suffer from sound sensitivity, and they often experience

an improvement after receiving magnesium supplements. According to

the Autism Research Review International (1990, Vol. 4, No. 4), 20

milligrams per each 10 pounds of body weight per day, is an

appropriate amount of magnesium. Improvement would occur within a

few days if the cause of the sensitivity is a magnesium deficiency.

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The use of Nutrasweet (aspartame), a popular artificial sweetener,

may also lead to hypersensitive hearing. Many chewable children's

vitamins contain aspartame as well as diet and low calorie foods.

Labels must be read in detail, as it may not be easily identified

that the product contains aspartame.

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Some medications have ototoxic side-effects that may result in

auditory hypersensitivity and/or other auditory system problems such

as tinnitus and vestibular dysfunction. Dr. Guy Berard cautions

against the use of antibiotics in the aminoglycocide family,

including erythromycin, gentamicin, garamycin, neomycin, tobramycin,

etc. Other medications with known ototoxic side effects include:

Advil, aspirin (salicyclates), Benadryl, Beta blockers, Desipramine

HCI (Norpramin), Empirin, Imipramine (Tofranil), Motrin (ibuprofen),

Naltrexone (Trexan), Sel-dane, Tavist, and Tegretol. Author Elaine

Suss reports in her book, When the Hearing Becomes Hard, that

diuretics are also known for ototoxicity and must be used with

caution.

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Other biochemical causes include changes in the system due to stress

and anxiety. Many people have reported increased auditory

hypersensitivity during periods of stress and anxiety, i.e., exam

week at college. Other sensory perceptions, such as tactile, taste

or smell, may also be heightened. This may be related to stress-

induced biochemical changes. Once the stress-related experience is

over, the hypersensitivity usually decreases. Nutritional stress

formulas may also be helpful.

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The sensory system may also be overaroused by changes in the

person's biochemistry, including increases in toxins produced by an

overgrowth of yeast and fungus, and possibly exposures to other

toxins (e.g., heavy metals, toxic chemicals). Auditory

hypersensitivity may escalate during this exposure and may be

restored to more normal levels when the toxins are removed. Other

techniques, such as brushing therapy, joint compression and deep

pressure, can sometimes be used to help calm the nervous system

while seeking appropriate treatment for the toxins. Physiological

causes may include: damage to the auditory system through exposure

to loud noise, traumas such as whiplash, and abnormalities in

function of the brainstem or higher cortical areas. A study by

Deborah Woodward of Woodward Audiology in McLeansville, NC revealed

that in children with autism, the binaural tolerance to speech

noise, prior to AIT, was 9 to 11 dBHTL less than the monaural

tolerance level (see The Sound Connection, 1994, Vol. 2, No. 2).

This may indicate abnormal amplification in the brainstem or lack of

bilateral inhibition. A study by Collett et al., published in The

Lancet (1993, Vol. 342, pages 923-924), produced results that may

indicate an alteration in the functioning of the medial

olivocochlear (MOC) bundle which is located in the brainstem, and

may explain sound sensitivity in autistic people.

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There is also speculation about a possible link between

hypersensitive hearing and the amygdala, located in the limbic

system of the brain. Dr. Margaret Bauman's research found that some

neurons in the amygdala are abnormal. There are auditory pathways to

the amygdala responsible for fear conditioning to sounds. It is

possible that the abnormal functioning in the amygdala plays a role

in the development of a dysfunctional fear response to sounds.

Perhaps AIT stimulates the amygdala in some way that reduces this

fear.

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It is clear that there are many possible causes of hypersensitive

hearing. One must learn about these causes and try to determine what

might be the cause for a particular individual. If that can be

determined, an appropriate intervention can be selected. When

certain things that are possible to control have been ruled out, AIT

may be an appropriate intervention to use for decreasing sound

sensitivity.

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