<unk> 's mechanism is not known, but it appears that, like hyperacusis, it may be caused by a dysfunction of the central auditory system in the brain and not of the ears. The perceived origin and context of the sound appears to be essential to trigger a reaction. A 2017 study found that the anterior insular cortex (which plays a role both in emotions like anger and in integrating outside input, such as sound, with input from organs such as the heart and lungs) causes more activity in other parts of the brain in response to triggers, particularly in the parts responsible for long-term memories, fear, and other emotions. It also found that people with<unk>  have higher amounts of myelin (a fatty substance that wraps around nerve cells in the brain to provide electrical insulation). It is not clear whether myelin is a cause or an effect of<unk>  and its triggering of other brain areas. A 2021 study found that the orofacial motor cortex, a part of the brain representing lip, jaw, and mouth movement, has enhanced activation for typical trigger sounds much more than for aversive or neutral sounds in<unk>  sufferers. It also found enhanced functional connectivity between orofacial motor cortex and secondary auditory cortex during sound perception for any sound. It further reported resting state fMRI functional connectivity between orofacial motor cortex and secondary auditory and visual brain areas as well as secondary interoceptive cortex (left anterior insula). This suggests that<unk> , which is typically thought of as a disorder of sound emotion processing, is a result of overactivation of the motor mirror neuron system involved in producing the movements associated with these trigger sounds or images.
Misophonia
Diplophonia
Hypophonia
Metamorphopsia
Agraphesthesia
Acrodynia
Copropraxia
Dysgraphia