Name = PAGENAME
DiseasesDB = 29099
ICD10 = ICD10|H|93|2|h|90
ICD9 = ICD9|388.42
MeshID = D012001
Hyperacusis is a health condition characterized by an over-sensitivity to certain frequency ranges of sound (a collapsed tolerance to normal environmental sound). A person with severe hyperacusis has difficulty tolerating everyday sounds, some of which may seem unpleasantly loud to that person but not to others.
It can be acquired as a result of damage sustained to the hearing apparatus, or
inner ear. There is speculation that the efferent portion of the auditory nerve(olivocochlear bundle) has been affected (efferent meaning fibers that originate in the brain which serve to regulate sounds). This theory also suggests that the efferent fibers of the auditory nerve are selectively damaged, while the hair cells that allow us to hear pure tones in an audiometric evaluation remain intact. In cases not involving aural trauma to the inner ear, hyperacusis can also be acquired as a result of damage to the brain or the neurological system. In these cases, hyperacusis can be defined as a cerebral processing problem specific to how the brain perceives sound. In rare cases, hyperacusis may be caused by a vestibular disorder. This type of hyperacusis, called vestibular hyperacusis, is caused by the brain perceiving certain sounds as motion input as well as auditory input.
Although severe hyperacusis is rare, a lesser form of hyperacusis affects musicians, making it difficult for them to play in the very loud environment of a rock band or orchestra which previously gave them no problems. It also makes attendance at loud discos or live events difficult for a proportion of the population. Given that sound levels at such events usually exceed recommended safe levels of exposure, this is a problem which is probably showing up variations between people, which may be genetic, or the result of stress or ill-health, or it may be caused by abnormal response in the
tensor tympaniand stapediusmuscles which function in the normal acoustic reflexresponse that protects the inner ear from loud sounds.
tinnituspatients complain of mild hyperacusis.
The most common cause of hyperacusis is overexposure to excessively high
decibellevels (or sound pressurelevels). Some come down with hyperacusis suddenly by firing a gun, having an airbag deploy in their car, experiencing any extremely loud sound, taking ear sensitive drugs, Lyme disease, Meniere’s, TMJ (Temporo-Mandibular Joint – jaw disorder), head injury, or surgery. Others are born with sound sensitivity (Superior Canal Dehiscence Syndrome), have had a history of ear infections, or come from a family that has had hearing problems. The causes include, but are not limited to:
Facial nervedysfunction (to Stapedius)
* Ear irrigation
Tension Myositis Syndrome
TMJ(Temporomandibular joint disorder)
Adverse drug reaction
Superior canal dehiscence syndrome(SCDS)
* Chronic ear infections
* Minor Head Injury
* A vestibular disorder: see below.
In cochlear hyperacusis (the most common form of hyperacusis), the symptoms are ear pain, annoyance, and general intolerance to any sounds that most people don't notice or consider unpleasant. Crying spells or panic attacks may result from cochlear hyperacusis. As many as 86% of hyperacusis sufferers also have
vestibular hyperacusis, the sufferer may experience feelings of dizziness, nausea, or a loss of balance when certain pitched sounds are present. For instance, someone with vestibular hyperacusis may feel like they are falling and as a result involuntarily grimace and clutch for something to brace themselves with. Anxiety, stress, and/or phonophobiamay be present in both types of hyperacusis. Someone with either form of hyperacusis may develop avoidant behavior in order to try to avoid a stressful sound situation or to avoid embarrassing themselves in a social situation that might involve noise.
A person suffering from hyperacusis might be startled by very low sound levels. Everyday sounds like shutting doors, ringing phones, running water, cooking, normal conversation and many others will hurt his/her ears. At extreme conditions even the use of earplugs isn't helping anymore and the patient may spend his life trying to avoid all sounds and just stay home.
The most common treatment for hyperacusis is retraining therapy which uses broadband noise. Tinnitus Retraining Therapy (TRT), a treatment originally used to treat tinnitus, uses broadband noise to treat hyperacusis.
Pink noisecan also be used to treat hyperacusis. By listening to broadband noise at soft levels for a disciplined period of time each day, patients can rebuild (i.e., re-establish) their tolerances to sound. When seeking treatment, it is important that the physician determine the patient's Loudness Discomfort Levels (LDL) so that hearing tests (brainstem auditory evoke response) or other diagnostic tests which involve loud noise ( MRI) do not worsen the patient's tolerance to sound.
Stephen Merritt, of The Magnetic Fields, suffers from this condition.
* Dublin singer-songwriter
Chris Singletonwas diagnosed with hyperacusis.
* [http://www.aitinstiute.org AIT Institute for Auditory Integration Training. AIT helps remediate hyperacute hearing]
* [http://www.hyperacusis.net The Hyperacusis Network]
* [http://www.tinnitus-pjj.com/ Tinnitus & Hyperacusis Center by Pawel J. Jastreboff]
* [http://www.tinnitus.org/home/frame/THC1.htm The Tinnitus and Hyperacusis Centre, London UK]
* [http://www.websitetoolbox.com/tool/post/danmalcore/vpost?id=851438 The crackling 'broken speaker' effect]
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