Misophonia, literally "hatred of sound", is a purported disorder in which negative emotions, thoughts, and physical reactions are triggered by specific sounds. It is also called "soft sound sensitivity syndrome," "select sound sensitivity syndrome" ("4S"), "decreased sound tolerance", and "sound-rage". Misophonia is not recognized as a disorder by standard diagnostic criteria, and there is no evidence-based research on its prevalence or treatment.

One study found that around 80% of the sounds were related to the mouth (eating, yawning, etc.) and around 60% were repetitive. A visual trigger may develop related to the trigger sound.

Reactions to the triggers can include aggression toward the origin of the sound, leaving, or 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.

People with misophonia are aware they experience it and that it is not normal; the disruption it causes to their lives ranges from mild to severe.

More Info: en.wikipedia.org