I consider myself to be a pretty tolerant person.
I'll eat just about any food you place in front of me. I'll read any book genre. I'll listen to any musical artist someone plays for me, even if I dislike it.
But there's one teeny little thing you can do around me that will set my teeth on edge. I'll sit, transfixed, unable to pay attention to the task and hand, my blood boiling and heart racing. I want to run. I want to scream.
But I can't, so I sit and count one, two, three...all the way to ten fingers. After ten, I know it's over.
I can't stand the sound of people clipping their nails.
Misophonia, or decreased tolerance to (in many cases, hatred of) certain sounds, is a newly-recognized phenomenon that remains poorly understand.
Sufferers are driven to distraction—even rage—by such insignificant sounds as chewing, tapping, breathing, whistling, scratching, humming, and footsteps. And, apparently, nail-clipping.
Worse yet, there is almost no research on the topic. A quick PubMed search reveals a few case studies and a handful of articles reiterating the above paragraph.
How common is this mysterious condition? It's not clear. Studies report prevalence of anywhere from 10% (of a general European population) to as much as 60% among those who also suffer from tinnitus, or "ringing in the ear." What's becoming somewhat clearer is its coincidence with certain anxiety disorders. A study published earlier this year reported that 52.4% of their misphonia sufferers met the criteria for obsessive-compulsive disorder (1).
Experts say the condition almost always begins in the early teens and worsens over time, where annoyance of one sound may expand to three or four sounds. Some also develop intolerance to watching others fidget or make repetitive movements out of the corner of their eyes. Others have a compulsion to mimic the sound or behavior.
It was only recently, in 2010, that a major textbook recognized misophonia as a nervous system condition (2).
Aage R. Moller, PhD of the University of Texas posits that the abnormality in misophonia sufferers is likely an issue in the brain's processing of the sound, not in physically hearing it. Why, for instance, might one specifically hate the sound of finger-tapping on a wooden desk, but remain unfazed by a woodpecker hammering on a tree?
Moller reasons that some sort of defect in central processing-our converging senses, memories, emotions, and cognition-is to blame. In other words, the problem may lie in how our brains perceive the sound, not how our ears physically convert sound waves into neural impulses.
But why are the particular noises that bother sufferers nearly always...bodily...in nature?
Sure, hearing a drill or hammer in the next room is irritating as anything, but why does the sound of something as silly as somebody clipping nails throw me into unfocused rage?
Anxiety is typically accompanied by a desire to escape and avoid. Could misophonia be evolutionary in nature-not unlike the sound of a baby's cries, designed to raise the stress of the parent until attended to? Or perhaps we relate more strongly to bodily sounds because we somehow feel like we're experiencing it, too (like the unpleasant sound of someone vomiting)?
As of now, it's all up to speculation. Luckily, active online groups and support forums help sufferers understand and cope with their, sometimes debilitating, distraction.
In the meantime, I'll continue to jam the earbuds a little deeper into my ears—but please, I beg of you, cut your nails at home!
(1) Schröder, A. et al. Misophonia: Diagnostic Criteria for a New Psychiatric Disorder. PLoS ONE 8, e54706 (2013).
(2) Moller, A.R. "Misophonia, Phonophobia, and ‘Exploding Head' Syndrome." In Textbook of Tinnitus. New York: Springer, 2010.