What Causes the disorder?
We don’t know the underlying causes of Misophonia, although there are numerous areas of speculation. There may be many causes for sound sensitivity or auditory over sensitivity.
Is it Neurological or Psychological or Auditory?
Misophonia does not appear to be “psychological” in nature (i.e. arising in the mind) versus physiological (i.e. having to do with the body and its systems).
The lines previously drawn between “neurological” and “psychological” are very much blurred today, as are audiology and neurology. It appears to involve the neurological and auditory systems and has psychological consequence.
Is it Genetic or Learned?
The distinction “nature versus nurture” (“genetic versus learned”) is not as clear as was previously thought. “Gene regulation” means that a gene (or genes) can be turned on or off based upon an individual’s interaction with the environment. Also, disorders such as misophonia may caused by the interaction of multiple genes, rather than being attributed to one gene.
This means that two people could have the gene(s) for misophonia and depending upon life experiences, one individual may manifest symptoms of the disorder and one may not. This also means that the age of onset of the disorder can vary depending on environmental circumstances. Therefore, this is a highly complex area that is certainly relevant and that we want to research, but it may not offer a quick and/or direct path to treatment (which is counter to what many of us have previously learned).
Are triggers “people-noises”, “body-noises” or repetitive noises”?
Although “chewing” and other “people-emanated noises”, such as coughing, sneezing, throat-clearing, etc. are very common triggers for people with Misophonia, other noises, (as well as visuals) have been noted as triggers in the early research.
The Jastreboffs (2001) originally noted that Misophonia sufferers aversively react to pattern-based sounds, some that are person-oriented (e.g. chewing, coughing, sneezing, etc.) many that are not (e.g. pencil tapping, basketball bouncing, typing on a keyboard, etc.).
This in fact, is how the Jastreboff’s distinguished Hyperacusis from Misophonia.
People with hyperacusis react to loud sounds, whereas those with misophonia react to “soft”, “pattern-based” “repetitive-based sounds” (2001).
This is a very complicated question since many processes interact within the nervous system (and sensory systems) ! The idea that a “trigger sound” may be attached to a specific person is confusing.This is an area that we hope to parse out through research, and that may prove to help with coping skills
What about Visuals and other Stimuli?
Many people with Misophonia also report aversive responsivity to visual stimuli. It is not yet clear within the research if this relates to movement, repetitive movement and/or other visual stimuli. It is not clear, as well, how many people with Misophonia have sensitivity to movement and/or other visual stimuli and if physiological and behavioral reactivity is the same. A subtype of Sensory Processing Disorder (Sensory Over-Responsivity) describes children who experience the fight/flight response as a result of auditory, visual, and other stimuli. Hopefully research will refine these subtypes in order to inform treatment.