Misophonia: Pet Peeve or Medical Condition?

All 17 years of my life I have only ever had one answer to the question: what is your pet peeve? "I simply cannot stand the sound of people chew!" was always my reply. I would get up and move from lunch tables and bring air pods to use in the kitchen of my house when I knew my sister was chomping her morning cereal. This year, on the ever-growing social media platform "TikTok," I learned about the condition of misophonia. This 60 second video explained that chewing, humming, pen clicking and other small repetitive noises have the potential to send some people into a frenzy, and that if you can relate to these people, estimated to make up about 20 percent of the population, you may have misophonia. So when I was assigned a research project on a topic of my choice, I chose to delve deeper into what misophonia really is: a pet peeve or a medical condition?

Eliza Stein's illustration of what it feels like to experience misophonia

       

Recognized as a condition since 2000, misophonia is an affective sound-processing disorder that links certain sounds to parts of the brain that trigger “fight-or-flight” responses. Some auditory stimuli, such as lip smacking or even loud breathing, are misinterpreted within the central nervous system and cause the individual to experience strong, unreasonable emotions. 

In 2017, a team of researchers from Newcastle University in the UK conducted a study that compared the brain activity of individuals with misophonia in response to everyday noises to the responses of people without misophonia. In this study, the researchers played three different auditory stimuli and observed the neurological and physical responses of a group of 42 volunteers—a test group of 20 claiming to have experienced severe symptoms of this condition, and a control group of 22 people who had not experienced any symptoms.

Baby crying to represent the typically annoying sounds 

Man eating burger representing the "triggering" sounds 

Rain on a street representing the neutral sounds

The two groups reacted to two out of the three types of sounds played similarly. When the research team played neutral, repetitive sounds, such as a boiling kettle or rain, or annoying sounds such as a baby's cry, neither group had much of a reaction. By contrast, when the team played a third type of sound, "triggering" sounds including breathing noises or loud chewing, the test group was observed to have slightly increased heart rates and skin conductivity, both signs that the “fight-or-flight” response was triggered. 

Graphs of heart rate and skin conductivity of those with and without misophonia in response to the different types of sounds

During these "triggering" sounds, there were significant differences in the neurological activity in the test group, specifically in the frontal lobe and the anterior insular cortex (AIC), which is responsible for managing emotional experiences. The AIC is a portion of the cerebral cortex folded deep within the fissure separating the temporal lobe from the parietal and frontal lobes, and its activation, along with the frontal lobe’s in those with misophonia demonstrates a lack of control of this type of signal (in response to these types of auditory stimuli) between these two parts of the brain.

In addition, the ventromedial prefrontal cortex (vmPFC), hippocampus, and amygdala were also shown to be active in the test group during "triggering" sounds. When the researchers looked into this part of the data, they found that those with misophonia actually had thicker myelin sheaths, a fatty substance that surrounds nerve cell "wires" to insulate them and increase the rate at which electrical impulses (messages) are passed along in the vmPFC of the brain. So not only is there a lack of control in the part of the brain that regulates emotional experiences, but the "triggering" messages also come through quickly and strongly. While some people may be bothered by some auditory stimuli, others emotionally cannot stand it due to the way their brain deals with that type of messaging. 

This study gave validation to many struggling with misophonia. Unfortunately, there is no easy fix for those with this condition. Behavioral cognitive therapy (BCT) may be an option to deal with misophonia but it isn't always helpful and can sometimes even be harmful. Neuroscientist Olana Tansley-Hancock, who also suffers from this condition, said that when treated for misophonia with BCT, it unfortunately made her more sensitive to a wider range of triggers. 

So, to be respectful of people who have misophonia, the next time you sit down to eat a yummy snack, consider chewing with your mouth closed.

by Dahlia Reynolds