Misophonia

Misophonia, literally 'hatred of sound', was proposed in 2000 as a condition in which negative emotions, thoughts, and physical reactions are triggered by specific sounds. Misophonia, literally 'hatred of sound', was proposed in 2000 as a condition in which negative emotions, thoughts, and physical reactions are triggered by specific sounds. Misophonia is not classified as an auditory or psychiatric condition, and so is different from phonophobia (fear of sound); there are no standard diagnostic criteria, and there is little research on how common it is or the treatment. Proponents suggest misophonia can adversely affect the ability to achieve life goals and to enjoy social situations. As of 2019 there were no evidence-based methods to manage the condition. Management generally consists of helping the person develop coping strategies; cognitive behavioral therapy has also been used. As of 2016 the literature on misophonia was limited. Some small studies show that people with misophonia generally have strong negative feelings, thoughts, and physical reactions to specific sounds, which the literature calls 'trigger sounds'. These sounds are apparently usually soft, but can be loud. One study found that around 80% of the sounds were related to the mouth (eating, slurping, chewing or popping gum, whispering, etc.), and around 60% were repetitive. A visual trigger may develop related to the trigger sound. It also appears that a misophonic reaction can occur in the absence of an actual sound. Reactions to the triggers can include aggression toward the origin of the sound, leaving, remaining in its presence but suffering, trying to block it or trying to mimic the sound. The first misophonic reaction may occur when a person is young and can originate from someone in a close relationship, or a pet. Particularly severe cases of misophonia may result in violent impulses toward the source of the sound. One such case described in the journal Psychiatry and Clinical Psychopharmacology detailed 'involuntary violence' exhibited by a sufferer in response to a trigger in the form of another person eating loudly. People with misophonia are aware they experience it and some consider it abnormal; the disruption it causes in their lives ranges from mild to severe. Avoidance and other behaviors can make it harder for people with this condition to achieve their goals and enjoy interpersonal interactions. Misophonia'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 misophonia 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 misophonia and its triggering of other brain areas.