First of all, we must establish the difference between the terms hyperacusis, an increase in hearing sensitivity that occurs for physiological reasons in the auditory canals, and misophonia, which has a psycho-neurological character.
There are experts who associate misophonia with an obsessive-compulsive disorder
Misophonia, for its part, is understood as a disorder in which the affected person experiences sensations ranging from extreme displeasure to possible states of panic, when repeatedly hearing certain types of sounds that are classified as everyday sounds, such as those related to chewing, slurping or breathing, and which do not exceed 50 decibels, which is within the normal range.
Figure 1: Misophonia's poster designed by Lauri Johnston
Numerous studies have been carried out and enough research has been done to establish the origins and causes of hyperacusis, a more or less well-known condition within the field of hearing disorders. However, little is known about misophonia. It was the American neuroscientists Pawel and Margaret Jastreboff (Jastreboff P. and M. Jastreboff, 2015) who first named the disorder in 2000, barely a line in the history book. Despite their research, they were unable to determine with certainty whether it was a neurological or a psychological disorder. Nevertheless, researchers are inclined to say that misophonia has a neurological character whereby the brain interprets certain sound stimuli as threats, which puts the body on alert, triggering emotions related to discomfort, nervousness and feelings of escape or confrontation.
“The neurobiological mechanisms and etiological causes of misophonia are still unknown; although it is thought that it results from abnormal functioning within the limbic system (the part of the brain that regulates emotions), the autonomic nervous system (the part of the brain that controls our involuntary organ functions such as breathing and our hearts beating, and the “fight or flight response”), and the auditory cortex (the part of the brain that manages hearing and interprets sounds). Respondent/classical conditioning also plays a role as previously neutral places and situations become associated with unpleasant sounds (for example, a young girl may be triggered by the sound of her brother chewing and may develop a conditioned reaction to the family’s dinner table regardless if anyone is eating at it).” (Lewin, Storch and Murphy, 2015)
Figure 2: Child suffering from misophonia.
The most characteristic feature of this disorder is that it does not have a specific register of trigger sounds, but that they vary according to the person who receives them, the person who emits them, the intentionality or spontaneity of the sounds, the place where the situation takes place, etc.
"The term misophonia comes from the Greek misos (aversion) and foné (sound). It is a psychological disorder consisting of a lack of tolerance to everyday sounds produced by others. (...) There are experts who associate misophonia with an obsessive-compulsive disorder, arguing that it could be caused by negative experiences associated with specific sounds. What is evident is that it is a disproportionately intense response of the nervous system to certain sounds due to a hyperactivation of the auditory system. (...) Thus, this sensitivity to low intensity sounds, 40/50 decibels, i.e. below normal conversation, could be one of the new mental disorders to be added to the next diagnostic manuals. People suffering from this problem differ from the rest in the degree to which they feel discomfort from these everyday sounds, being able to modify their habits so as not to have to listen to them, which often leads them to isolate themselves in an area they consider safe or even to use earplugs". Carlos Hidalgo, psychologist.
Little or nothing is known about this condition, which can affect a large part of the population. Starting from a key concept: obsessive-compulsive disorder, which includes misophonia, we could establish the theoretical basis for more extensive research on the subject. Perhaps then, many sufferers would find refuge in the study to be able to convey their concerns, as sometimes, it is too confusing or even useless to communicate that the sound hurts you.
Figure 3: Nails on a blackboard.
We need to raise awareness of this condition, as it is more than likely that people close to us experience it and suffer in silence for fear of reprisals. Chewing with our mouths closed, trying not to yawn too loudly, or not biting our nails, may be one of the first steps to take to make the space we cohabit a more comfortable place for those we love. Think carefully, we can make our world a quieter and more livable place.
Hidalgo, Carlos (2017). La misofonía. El Periódico Mediterráneo. Available on: https://www.elperiodicomediterraneo.com/opinion/2017/07/09/misofonia-41518430.html
Jastreboff, P. y M. Jastreboff, (2015). Decreased sound tolerance: hyperacusis, misophonia, diplacousis, and polyacousis. Handbook of Clinical Neurology. DOI: https://doi.org/10.1016/B978-0-444-62630-1.00021-4
Lewin, Adam B., Storch, Eric A. and Murphy, Tanya k. (2015). Like nails on a chalkboard: A misophonia overview. OCD Newsletter. Available on: https://iocdf.org/expert-opinions/misophonia/
Figure 1: Misophonia's poster designed by Lauri Johnston. Available on: https://cdn.dribbble.com/users/12843/screenshots/5273769/misophonia_4x.jpg
Figure 2: Child suffering from misophonia. Available on: https://www.psychologytoday.com/gb/blog/fearless-you/201601/7-warning-signs-your-child-might-have-misophonia
Figure 3: Nails on a blackboard. Available on: https://www.newscientist.com/article/2123018-the-feeling-you-get-when-nails-scratch-a-blackboard-has-a-name/