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Sound Sensitivity: A Summary of Probable Causes of Hypersensitivity

to Sound (also know as Hyperacute Hearing)

The causes of auditory sensitivity can be classified into two

categories: biochemical (which includes nutritional deficiency and

drug side-effects) and physiological.

MAGNESIUM DEFICIENCY:

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.

ASPARTAME USE (Nutrasweet)

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.

OTOTOXIC MEDICATIONS

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.

STRESS AND ANXIETY

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.

AN OVERLOADED SENSORY SYSTEM

The sensory system may also be over aroused 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 (hyperacute hearing) 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.

OTHER PHYSIOLOGICAL CAUSES

Physiological causes may include: damage to the auditory system

through exposure to loud noise, traumas such as whiplash,

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 Auditory Integration Training, 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.

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

Auditory Integration Training stimulates the amygdala in some way

that reduces this fear.

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, Auditory

Integration Training may be an appropriate intervention to use for

decreasing sound sensitivity.

This article appeared in The Sound Connection, a quarterly newsletter

of the Society for Auditory Intervention Techniques Original document.