Hyperacusis may be defined as a reduction of normal tolerance for everyday sounds. 

It is also defined as a collapse of the normal
range of tolerance for sounds that is present in otherwise normally functioning ears. 

People with hyperacusis may find that certain sounds are more difficult to listen to than others, and some sounds may cause pain in the ears, even when those sounds don't bother others.  Often, the most disturbing or painful sounds can be sudden high pitched noises like alarms, bus brakes, silverware and dishes, children's screams, and clapping.   Many sounds that were previously perceived as normally loud or non intrusive, can be painful, annoying, seem amplified, or irritating.  This is a very frustrating situation for most people as sound and noise are present in nearly every work, social, or recreational settings! 

Sometimes, hyperacusis can be so severe that people begin to avoid any public or social setting in an attempt to protect their ears from any sounds.  It can be very difficult for family members or medical providers to understand and support the person with hyperacusis, which cannot be seen in images, like a broken bone. 

Hyperacusis can come on suddenly or gradually.  It can initially affect only one ear but generally speaking, within a short time, the condition is almost always bilateral. It can be mild or severe. Often, people who have hyperacusis also have tinnitus, or phantom noises in their auditory system (ringing, buzzing, chirping, humming, or beating).  Research has shown that about half of all people who have tinnitus, also have reduced tolerance for moderate or loud sounds, known as hyperacusis. No one is quite sure how many people in the world suffer from hyperacusis without tinnitus.   

Adults and children can develop hyperacusis: certain birth conditions are associated with hyperacusis, including Williams Syndrome and autism.  Since the auditory system connects the outer organs of hearing with the central nervous system, through a complex series of neural pathways, that literally pass through or coordinate with many diverse areas of the brain, there are endless possibilities for dysfunction that may contribute to hyperacusis.

In other words, the understanding of the mechanism of hyperacusis is often extremely challenging and it is yet impossible to specifically locate a single structural change that is responsible for hyperacusis.  There is no objective test for hyperacusis.  Most people who develop hyperacusis will be referred to an ear doctor and receive a thorough evaluation including a full audiological assessment to determine the state of the auditory-vestibular system.  In the USA, Doctors of Audiology perform these important assessments. 

Careful case history and the use of Audiological Tests can help diagnose the condition. In particular, the LDL Test (loudness discomfort test) is of critical importance in determining the degree of hyperacusis. Normal LDL levels in most human ears tend to fall at 90 dB or greater at various pitches or frequencies.  Again, there is very little normative data on LDL results in normal hearng populations for comparison.

The billions of electrical signals that are processed by our central nervous system must be ordered and prioritized for our practical use.  If you are reading a good book, and a bee stings you, the effect is dramatic and the primary activity instantaneously shifts!  In the case of hyperacusis, detecting which of these billions of electrical or biochemical processes has changed is still impossible.  But with proper, experienced, thorough investigation, and coordination with all the medical providers, often a reasonable conclusion can be established for a particular patient.

 The most common causes of hyperacusis are

          Hearing Loss, Noise Injury

          Head Injury or Whiplash type injury

          Acoustic Trauma, i.e. airbag explosion or gunshot

          Adverse reaction to medication or surgeries, particularly Central Nervous System drugs

          Chronic ear infections

          Auto immune disorders

          Unknown

 By far, the most common causes of hyperacusis are noise injuries and head injuries.  Neck injuries can also contribute, i.e., whiplash.  There remain huge areas of medical scientific research and data accumulation that must be explored before we can really begin to define and understand the different types of hyperacusis, and the origins of this troubling disorder. 

 Good Links:  www.tinnitus-audiology.com  Dr. Marsha Johnson's main website, full of articles, links, research, and more 


Other Auditory Conditions which can Affect your Hearing: 

Phonophobia:  Fear of sounds, frightened of certain pitches or tones or noises, an enhancement of hyperacusis sometimes and sometimes a stand-alone condition by itself, often using earplugs to avoid sound exposure.  The treatment of phonophobia can be administered by audiologists as well as other professionally trained medical or psychological providers.  Often, when coupled with hyperacusis, those who have phonophobia can benefit and improve by using a form of sound therapy.  It has been suggested that many individuals who suffer from hyperacusis develop phonophobia and misophonia.

Hearing Loss with Recruitment:  When a person has significant hearing loss with cochlear damage and nerve damage, sound sensitivity can be called recruitment, which is an abnormal growth of loudness, in other words, a tone cannot be heard due to hearing loss until it reaches a certain loudness, then it becomes rapidly very loud rather than the normally gradual increase in loudness experienced by normal hearers.  Recruitment is a condition that must be managed by an audiologist when fitting and programming a hearing aid, and recruitment levels can be increased over time as hearing aid use increases and re-stimulates the hearing organs.  All licensed Audiologists are specifically trained to provide help for those with recruiting ears.

Misophonia: Dis-Like of Sounds, finding sound itself aggravating or overwhelming, a feeling of sensory overload or over-stimulation, this can lead to self-isolation, removal from noisy environments, using earplugs often, withdrawing from work or social situations, avoiding sounds or noises. The treatment for misophonia is based on the work of Dr. Pawel & Margaret Jastreboff and needs to be administered by specifically trained medical providers. A new network of qualified providers can be found at www.misophonia-provider.com for those who suffer the symptoms of this malady. For the purposes of this site, misophonia is defined as hatred or intense dislike of many sounds, including louder or softer sounds, even all sounds.

A recongized subset of misophonia, Selective Sound Sensitivity Syndrome (4S):  These individuals are a special group of people who have specific characteristics to their auditory sensitivities:  onset from ages five to fifteen, on average, with sudden awareness of specific, softer, particular trigger sounds, often eating, chewing, or breathing sounds, that can overwhelm every other environmental focus or stimulus, and these trigger sounds can provoke an immediate visceral reaction, including emotional and physiogical reactions such as rage, panic, disorientation or loss of cognition, or evoke a fight or flight response.  Those with 4S tolerate louder sounds very well and most often do not have hyperacusis or recruitment. 

4S is poorly understood or defined, however, it is suspected to be far more wide spread than previously understood.  4S was named by Dr. Marsha Johnson, Audiologist, in the 1990s based on her clinical work in Portland, Oregon.  It is suspected that there are genetic factors in 4S due to its characteristic patterns. 

Recent articles in September 2011 in the NYT (Joyce Cohen, Misophonia) and an interview on the Today Show (January Misophonia) by Dr. Johnson have created a huge wave of attention and interest in this subject.  There are now treatment protocols available at regional centers where experienced audiologists are working with experienced psychologists to create new approaches to improving and managing misophonia.   Do visit the regional website at www.misophonia-provider.com

There is great interest in this area as a condition in the auditory science world and it is hoped that a study will soon emerge with single focus on this population.  The support group  listed below has more than 2000 active members who all fall under the definition of misophonia.  Clearly, 4S is not hyperacusis.

JOIN OUR NEW YAHOO GROUP TO TALK ABOUT
MISOPHONIA/SELECTIVE SOUND SENSITIVITY ISSUES--where people find soft sounds objectionable

ALSO VISIT OUR NEW PUBLIC INFO SITE: www.soundsensitivity.info