What is hyperacusis?

 

Hyperacusis (Hyper-a-CU-sis) is a collapsed tolerance to normal environmental sound.  All sounds are perceived as too loud.  Also quick shifts in sound are difficult for the patient to tolerate. 

 

Hyperacusis can occur in one or both ears.  It can occur suddenly or over a period of time.  It can be accompanied with or without hearing loss.  If the hearing loss is significant the condition is called recruitment.  If the hearing loss is minimal, typically it is referred to as hyperacusis.

 

Hyperacusis can also be accompanied by tinnitus (Tin-EYE-tus).  Tinnitus is the perception of sound in the head when no outside sound is present.  It is typically referred to as ringing in the ears but others may describe the sound as hissing, roaring, pulsing, whooshing, chirping, whistling or clicking have been described.

 

Is hyperacusis a common problem?

 

No.  Hyperacusis is rare.  The most common reaction to a noise injury is hearing loss and/or tinnitus.  It has been commonly reported that 50 million people have tinnitus.  A common report from the American Tinnitus Association (www.ata.org) has revealed that approximately 40% of tinnitus patients have some difficulty with hyperacusis.  Actually 40% of tinnitus patients have sensitivity to sound but this is NOT hyperacusis.  It is only when the patient has significant, pronounced sensitivity to sound where their loudness discomfort levels (LDLs) so collapsed that they impact their lives on a daily basis.  True hyperacusis is so rare that most hearing doctors do not know of the condition and often subject the patient to hearing tests which further collapse the patients tolerance to sound.  It is for this reason that a doctor must establish the patients LDLs before any hearing tests are administered.

 

Is hyperacusis a disease?

 

No.  Just as a fever or headache accompanies many different illnesses, hyperacusis is a symptom.  Although many times people complain of being sensitive to sound for a short period of time following a loud rock concert or while they have a  migraine headache, this is not hyperacusis.  Hyperacusis a symptom where the patients tolerance to sound does not improve.  The most common cause is from a significant noise injury.  Other causes of hyperacusis can come from Lyme disease, Bells Palsy, TMJ, drugs which are not ear friendly, irrigating (cleaning) the ears, Williams Syndrome, Meneires Disease, and just a host of other illnesses.

 

What causes hyperacusis?

 

There is speculation that the efferent portion of the auditory nerve has been affected (efferent meaning fibers that orginate in the brain which serve to regulate sounds).  Others feel hyperacusis is a brain processing problem specific to how the brain perceives sound.  Others feel it is a combination of both. 

 

Why is my hyperacusis often worse when I wake up and before I go to bed?

 

Individuals with hyperacusis have ears that yearn for total silence.  Night time is quiet time.  After a full night of total quiet, it is often hard for the hyperacusis patient to face the noise of a new day.  Some hyperacusis patients even wear ear protection at night and it even becomes more difficult to face the noise of a new day.  This is just one example of why the patient is being given a wrong directive from their survival instinct and living in total silence is the wrong approach. 

 

Hyperacusis patients also experience sound fatique.  At the end of a day their ears are tired and less tolerant of noise.  Almost all hyperacusis patients experience a symptom commonly referred to as fullness in the ears.  It is a feeling where the patient feels pressure in the ear or the sensation that someone is actually pressing on their eardrum.  Other patients feel pain or burning in the ears.  From time to time doctors will tell the patient that the ears are incapable of experiencing pain.  This is not true. 

 

What should I do about my hyperacusis?

 

You should have a medical examination by someone who is knowledgeable about hyperacusis.  There are very few doctors in the world that understand hyperacusis.  As a starting point you can visit the website for the Tinnitus Retraining Therapy Association (http://www.tinnitus-pjj.com/referral.html).   Individuals listed here also administer a retraining therapy which is similar to tinnitus retraining but is customized for the hyperacusis patient so they can re-establish their tolerances to sound. 

 

What is retraining therapy?

 

Retraining therapy uses broadband sound to re-establish a patients tolerances to sound.  Broadband sound is a broad brush which covers many colors of sound.  White broadband sound is the culmination of all sound frequencies.  White sound however contains equal energy in all frequencies including the higher frequencies.  The hyperacusis patient is highly sensitive to the higher frequencies like those above 8,000 Hertz.  To speed the recovery of a hyperacusis patient it is important for the patient to have a hearing diet of very soft sound which does not include the high frequencies.  The answer to this is called pink sound.  If the patient softly listens to pink sound for a disciplined period of time each day they usually find that their tolerances improve and they can return to the mainstream of life.  There are two delivery systems for pink sound.  One is through wearing a special hearing aid called a sound generator.  It looks like a hearing aid which is designed to delivery broadband pink sound into the ear.  The other delivery system is by playing a pink sound CD which is available through this network (see Helpfull Products).

Can the sound of a dentist's drill cause or worsen tinnitus or hyperacusis?

Jack Vernon, Ph.D. writes, "There is no doubt that dental drilling can exacerbate tinnitus (or hyperacusis) in some patients, and I'd much rather be cautious than sorry.  For dental drilling, I always recommend 5 seconds of drilling then 10 seconds off - 5 on, 10 off - until the job is finished.  The sound is directly conducted to the inner ear by bone conduction, and wearing ear protection will only serve a partial purpose.  Some dentists charge extra for the "5 on/10 off" approach, but most willingly cooperate.  The impact that noise has on hearing is controlled by two elements: the intensity of the sound (how loud it is) and the duration of the sound.  We cannot control the intensity for the dental drill, but we can control the duration of the exposure.

Vernon and Sanders: Tinnitus - Questions and Answers, 2001, pp. 61-63