Hyperacusis
Definitions of hyperacusis can vary significantly; it often revolves around damage to or dysfunction of the stapes bone, stapedius muscle or tensor tympani (eardrum).
[1][10] Reported prevalence estimates vary widely, and further research is needed to obtain strong epidemiological data.
[21] A setback is a temporary exacerbation of symptoms, a worsening of the perception of loudness or pain from sound, often due to a particular noise exposure.
[32] Bell's palsy can trigger hyperacusis if the associated flaccid paralysis affects the tensor tympani, and stapedius, two small muscles of the middle ear.
[33] Paralysis of the stapedius muscle prevents its function in dampening the oscillations of the ossicles, causing sound to be abnormally loud on the affected side.
[11] Recently, it has been discovered that individuals with one copy of the GJB2 (Cx26) genetic mutation exhibit hearing that is more sensitive than average, akin to hyperacusis.
[11] As one possible mechanism, adaptation processes in the auditory brain that influence the dynamic range of neural responses are assumed to be distorted by irregular input from the inner ear.
Gain of function of these type II afferent fibers may be caused by a flood of ATP after hair cell damage.
[7][8] The model details how symptoms may be initiated by tensor tympani muscle damage or overload due to acoustic shock or trauma.
The muscle is then forced to create energy without sufficient oxygen, which results in the release of lactic acid into the middle ear space.
This may be due to the trigeminocervical complex in the brainstem, which integrates input from and output to various regions of the head and neck, including the middle ear.
The model also explains how whiplash injuries, temporomandibular joint dysfunction, and other conditions affecting the head and neck regions may influence the function of the tensor tympani muscle and contribute to ear symptoms such as pain hyperacusis.
The difference is that, in addition to the hearing threshold at each test frequency, the lowest uncomfortable sound level is also measured.
[41] In addition to self-report questionnaires, audiologists may employ a variety of other techniques to evaluate auditory function in patients experiencing noise sensitivity.
The majority of audiologists report insufficient formal education in this area, likely due in part to the current lack of consensus in the literature regarding definitions and treatment of hyperacusis.
[42] Setback prevention and reduction of pain symptoms are high priorities among those with hyperacusis and noxacusis, which is often managed through a combination of controlling the environment so as to avoid loud sounds, soundproofing, and wearing hearing protection, such as earplugs and safety earmuffs.
[43][44] Preliminary research has shown that individuals with pain hyperacusis can experience an exacerbation of their symptoms when not adequately protecting themselves against loud sounds.
Some audiologists may advise against using hearing protection in normal sound environments, claiming it can cause or worsen hyperacusis.
By listening to broadband noise at soft levels for a disciplined period of time each day, some patients can rebuild (i.e., re-establish) their tolerances to sound.
Studies have shown improved loudness discomfort levels in patients with hyperacusis after round and oval window reinforcement.
[15] A case of chronic ear pain associated with hyperacusis after exposure to loud noise at a concert was successfully treated with tympanic neurectomy.
Hashir et al. (2019) interviewed 292 patients and found that 15.75% had expressed suicidal ideations in the previous two weeks of the study.
