Noisy eaters aren’t exactly pleasant company for anyone. But if you fly into a rage when you hear a stranger noisily munching on some popcorn, you might have a condition called misophonia. It’s characterized by an extreme reaction to a specific noise, and for many misophonic people, noisy eating is a major trigger. 
Note that misophonia is, by definition, an excessive reaction; if you’re simply slightly annoyed when you hear a family member munching, you probably don’t qualify as misophonic. To meet the criteria for diagnosis, you need to exhibit a clear physical response; if you become irrationally angry, disgusted, or irritated, you may qualify. In most cases, misophonia develops at an early age. Many patients don’t experience a negative reaction when they’re the source of their own trigger sounds—so, for instance, you might not be bothered by your own munching, but you may fly into a rage when you’re in the presence of a noisy eater. Misophonia often becomes more severe over time. Scientists believe that the issue is due to a malfunctioning fight-or-flight response, but there’s some debate over the cause of the condition.
What’s more, the brains of people with misophonia are notably different.
In a recent study in the UK, researchers performed brain scans on 22 misophonic people and 20 other individuals. While the study participants waited in an magnetic resonance imaging (MRI) machine, the researchers played a variety of cues, including neutral sounds, unpleasant sounds (such as people screaming), and misophonic trigger sounds. 
Predictably, misophonic patients were most annoyed by their trigger sounds. When confronted with their triggers, the patients experienced an overreacting anterior insular cortex, the part of the brain tasked with connecting senses to emotions. Researchers expected some structural differences, since misophonia typically develops early in a patient’s life while the brain is still forming. The results of the study were published in the scientific journal Current Biology. 
“Misophonia does not feature in any neurological or psychiatric classification of disorders; sufferers do not report it for fear of the stigma that this might cause, and clinicians are commonly unaware of the disorder,” the study’s authors note, adding that the results of the research should help clinicians classify and treat misophonia.
If you think that you have misophonia, new treatments could be on the way.
The BBC reports that medical researchers have hypothesized that low levels of targeted electricity could help to disrupt the brain activity that seems to compel misophonia. 
“I hope this [research] will reassure sufferers,” said Tim Griffiths, professor of cognitive neurology at Newcastle University and University College London. “I was part of the sceptical community myself until we saw patients in the clinic and understood how strikingly similar the features are. We now have evidence to establish the basis for the disorder through the differences in brain control mechanism in misophonia.” 
In the meantime, behavioral therapy may help to curb some of the effects. Parents should also pursue treatment for young children who display signs of misophonia, as the condition may be more easily treated early in life.
