Why Do Some People Hate Sounds Like Chewing?

anger and anxiety. Miss Aphonia is a condition that often evokes strong negative feelings at a person in response to certain sounds, from other people's eating and drinking, to pen clicking and keyboard tapping to simple breathing, so much so that they have to get away from the source of those sounds. But science is working on it. Back in twenty seventeen, research published in the journal Current Biology studied the brains of people with missophonia to see how their

brains process emotions after hearing certain sounds. Evaluated the data of forty two participants, a twenty with missophonia and twenty two without. People who don't have missophonia can generally tune out everyday sounds that might be a bit bothersome. For people with missophonia, the sensitivity comes from the pattern of the sound, though not its volume. For the article, this

episode is based on how stuff works. Spoke with study co author doctor Subinder Kumar, now a research assistant professor of neurosurgery at the University of Iowa. He explained that the aversion to certain sounds is quote a sudden realization on the part of the person who has missophonia. They just can't tolerate the sound and it just goes on and on over time. While it's not known exactly how common the condition is, it can be debilitating for the

people who do have it. On average, symptoms start around age twelve, but they can appear as early as age five. Trigger sounds often incite rage and anxiety. The sensitivity can get so intense that a person might lash out verbally in response to a sound or begin avoiding social situations where the sound might occur, especially if they haven't been diagnosed and have trouble explaining why they're reacting so strongly.

Imagine a person with missophonia living with a friend, but they don't want to talk because they're bothered by the sound of their friends breathing. Kumar said, then it gets a little bit more complicated because they also have this feeling that other people are not believing them so they

suffer in silence. The researchers studied measurements from functional and structural magnetic resonance imaging, that is, fMRI and MRI, observing parts of the brain used for processing perceptions and emotions. They also monitored physiological data like heart rate and sweat

responses to measure participants stress levels. Participants heard three kinds of sounds, trigger sounds like eating, breathe, or drinking, unpleasant sounds like a baby's cry or a person's scream, and neutral sounds like a busy cafe or the sound of rain. Both groups were asked to rate how annoying the sounds were. Those with mesophonia rated how much the sounds triggered mesophonic reactions.

Those without it rated how antisocial the sounds would make them or how much they would dislike being around the noise. The group with mesophonia did experience distress typical of their disorder from the trigger sounds, but the unpleasant sounds didn't produce the same response. After hearing the trigger sounds, the group with misophonia experienced increased heart rates in sweating measured

through galvanic skin responses, but also called electrodermal activity. Basically, when we sweat, our skin becomes more electrically conducive because water is conducive, so you can measure even small changes in whether or how much we're sweating by attaching electricrodes to two fingertips and sending a tiny amount of current through them. Increases in heart rate and sweat indicate that we're experiencing stress. According to the authors, these responses indicate

a fight or flight response to the trigger sounds. They wrote that people with messophonia tend quote to escape from the environment of trigger sounds or experience anxiety and anger if unable to escape. The group with missophonia in the study also exhibited abnormal salience. Salience is how much we notice something. The trigger sounds stood out more for these participants, and the parts of their brains involved in processing salience were more active than was observed in the other participants.

In people with missphonia, the trigger sounds activated the anterior insular cortex of the brain, a network that directs our attention towards stimuli that are, for whatever reason, irrelevant or meaningful to us. Why Normally, this part of the brain helps us say hear our name, in a noisy room because we've learned that that's important, or it might draw our attention to the color red or yellow for evolutionary reasons.

In the participants with missophonia, the trigger sounds also activated parts of the brain related to processing and regulating emotion. The researchers also asked all of the participants questions about body consciousness based on notions of the private body, the public body, and body competence. Kumar explained that the private body is basically inner perception, like when a person can

easily sense their heartbeat. The public or outer body references your consciousness about presenting yourself to and being perceived by others. Body competence refers to how strong, fast, and coordinated you

feel like you are in comparison to other people. Both groups had similar scores in body competence, but Kumar said found that people with misceophonia had a higher score on the private body and also on the public body, so they were definitely perceiving their body internally differently compared to

people who don't have missophonia. The researcher's data can't tell us whether this unusual self perception is a cause of or a result of missophonia, but Kumar is optimistic that further research can be directed to basically quiet the brain structures related to the condition, and he hopes that in the meanwhile, the fact that research is being done will bring people a bit of comfort. Today's episode is based on the article why do some people hate the sound

of chewing? Scientists might have the answer on how stuffworks dot Com, written by Shelley Dancy. Brain Stuff is production by Heart Radio in partnership with how stuffworks dot Com and is produced by Tyler Klang. Four more podcasts my heart Radio, visit the iHeartRadio app podcasts, or wherever you listen to your favorite shows.