Honestly everyone is probably at least a little bothered by mouth noises. It’s not like anyone likes listening to other people chew and smack their lips. Right? Right? Some people hearing about mouth noises probably got a little more than just uncomfortable at the notion of them–which might have others asking: why do people hate mouth noises?
It’s a Real Thing
Maybe it’s not mouth noises, there just happens to be a noise that drives you absolutely bonkers. Mouth noises are one of the most commonly cited ones. Typically it’s the ones people make when they chew. Having these specific noise triggers is called misophonia. The disorder also covers visual triggers, though the vast majority of misophonia cases are noise-related. Of those, the majority seems to focus on noises made by other people.
There are a couple similar conditions that you might want to wrap together, like phonophobia or hyperacusis. Phonophobia is something you can probably pick apart just by reading it, it’s a fear of specific sounds. Triggers for phonophobia often differ from misophonia. Most of them come from the environment, like traffic. Hyperacusis is an increased sensitivity to specific frequencies of sound, like any kind of high pitched whine. The big difference, which we actually care about here, is what causes the disorder. Phonophobia and hyperacusis may present similarly, but phonophobia means there’s nothing physically abnormal with the patient’s ears (or the pathways that gets signals from the ear to the brain). Hyperacusis typically implies damage to the ear, which can be acquired from overexposure to loud noises or a head injury.
Where does misophonia fit in?
For starters, misophonia is triggered by specific noises. While they’re not the same as common phonophobia triggers, misophonia is not characterized by a general sensitivity to sound. People with misophonia rate noises associated with eating and breathing as far more unpleasant than those without misophonia. Expected. They also rate neutral noises or universally unpleasant noises similarly to those who do not suffer from misophonia. Similarly expected, but important foundation. Misophonia’s triggers do also show more physical signs of stress, like an increased heart rate. Also probably something you expected to see.
Unlike hyperacusis, little evidence suggests misophonia has a root cause in physical trauma to the head or ear. Other studies suggest that misophonia can be likened to an exaggerated response to something those without misophonia are already going to respond to. That’s just a long way of saying “nobody likes mouth noises.” There does appear to be more going on in the brain though, those with misophonia have increased activity in certain parts of the brain when exposed to a misophonic trigger. One of the areas without increased activity is the amygdala. Which indicates that misophonia is distinct from a phobia–anxiety and fear do not appear to be the driving response to misophonia triggers.
Misophonia research is still in its infancy–with new evidence cropping up as recently as 2021. Remember earlier when we said some misophonia triggers are repetitive movements? Well newer research has also shown increased activity in the parts of the brain governing the movement of your mouth in misophonia sufferers. This suggests mouth noises being one of the most common misophonia triggers is the result of overactivity in this part of the brain.
Speaking of ears, see if you know how it works here.