Hyperacusis

Overview

Hyperacusis is a condition characterized by an over-sensitivity to a specific frequency of sound or intolerance to reasonable environmental sounds. A person with hyperacusis has difficulty accepting everyday sounds; some sounds may seem offensively loud to that person but not to others. In hyperacusis, a person gives inappropriate or exaggerated responses to sounds that are neither uncomfortable nor threatening loud to an average person; even low-intensity sounds can elicit the reaction.

Classification

Based on the symptoms, hyperacusis may be classified as Cochlear and vestibular hyperacusis.

1) Cochlear hyperacusis: (the most common form of hyperacusis) presents with 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 tinnitus.

2) Vestibular hyperacusis: The sufferer may experience dizziness, nausea, or a loss of balance when certain pitched sounds are present.

Anxiety, stress, and phonophobia may be present in both types of hyperacusis. Someone with either form of hyperacusis may develop avoidant behavior to avoid a stressful sound situation or avoid embarrassing themself in a social case that might involve noise.

Pathophysiology

Hyperacusis can be developed because of damage to the inner ear or hearing apparatus, affecting efferent part of the auditory nerve, and fibers that come out from the brain that control sounds. In this process, tissues of the auditory nerve are damaged, though the hair cells that permit us to hear pure tones remain integral. It can be as a result of injury to the neurological system of the brain. In some cases, hyperacusis may be triggered by a vestibular disorder. Stapes hypermobility can also be one of the causes of peripheral hyperacusis. Situations that comprise paralysis of the facial nerve (i.e., Ramsay-Hunt syndrome, Bell’s palsy, and Lyme disease) are involved in the causes of the condition.Hyperacusis increases in extent during anxiety, tiredness, or stress. The mechanism involved during stress, include endogenous dynorphins release into the synaptic region underneath inner hair cells. It potentiates the neurotransmitter glutamate, triggering sound to be seeming with excessive noise.

Causes

The Common causes of hyperacusis include:

• Loud noise experience.
• Recreational and industrial noise acquaintance and noise-related hearing loss.
• Expert musicians specifically those playing rock music and exposed to extended periods of amplified sound.
• Other causes that can lead to hyperacusis include migraine, Lyme disease, psychiatric illness such as post-traumatic stress disorder, and Williams syndrome.
• The most common cause of hyperacusis is overexposure to excessively high decibel levels (or sound pressure levels).
• Some come down with hyperacusis suddenly by firing a gun, having an airbag deploy in their car, taking ear sensitive drugs.

Other causes can be due to the following:

• Severe head trauma
• Facial nerve dysfunction (to Stapedius)
• Surgery
• Ear irrigation
• TMJ (Temporomandibular joint disorder)
• Adverse drug reaction
• Williams Syndrome
• Autism
• Bell's palsy
• Ménière's disease
• Asperger syndrome
• Superior Canal Dehiscence Syndrome
• Chronic ear infections
• Minor Head Injury
• A vestibular disorder: see below.

Symptoms

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 tinnitus.

In 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 phonophobia may 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 themself in a social situation that might involve noise.

Treatment

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 noise can 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.

People

• Stephen Merritt, of The Magnetic Fields, suffers from this condition.

See also

• Hearing impairment
• Tinnitus

External links

• AIT Institute for Auditory Integration Training. AIT helps remediate hyperacute hearing
• The Hyperacusis Network
• Tinnitus & Hyperacusis Center by Pawel J. Jastreboff
• The Tinnitus and Hyperacusis Centre, London UK