Do you ever get slightly nauseous when you hear someone chewing with their mouth open? What about the symphony of nails or chalk screeching across a chalkboard? It doesn’t feel good.

If those sounds grate your nerves beyond words, know that it’s all in your head. Specifically, in your ears and brain!

According to a study by researchers from the University of Cologne in Germany, your ear canal makes the sound of a chalkboard scrape unbearable by amplifying it. Essentially, the shape of the ear pumps up the volume.

The same thing happens when a baby cries loudly or when someone screams, and they all fall under the same frequency range. Head researcher Professor Michael Oehler shared that 2,000 to 4,000 hertz is home to the ultra-annoying nail + chalkboard combo.

Dr. Oehler’s study also revealed that perhaps physiology and psychology play a role in our responses. In the test group, some participants were told they would be listening to music (with the offending sound playing in the background), and others were told the direct source of the offending sound.

The anticipation of hearing a terrible noise influenced the reactions of participants. Physical changes, in skin, heart rate, and blood pressure were noted. Interestingly, sounds were more tolerable when blended with music.

Since our ears are extra sensitive at this range, our brain processes the sound as a form of emotional stress, and there’s a measurable physical response akin to hairs raising on the back of one’s neck.

A separate study by neuroscientists at Newcastle University in the UK measured that reaction with the use of MRI. Volunteers were exposed to 74 different noises while undergoing MRIs, with most of those noises being cringe-inducing. What they found is that the amygdala center in the brain registered certain sounds with negative emotions.

In communication with the brain’s auditory cortex, the amygdala showed high activity in the MRI scan. For this study, nails on a chalkboard qualified as one of the top five worst sounds. What else ranked?

Winners likes these: knife on a bottle, fork on glass, chalk on a chalkboard, squealing brakes, ruler on a bottle, and more. The only reprieve was the soothing sound of bubbling water.

You can’t always control when or if you’ll hear the infamous nails on a chalkboard noise, but just the thought of it probably gives you the willies. Now you know why. And this also may give some insight into the popularity of whiteboards in classrooms.

Click below so you can hear the sound itself and to test out the theory. Just kidding! But you will get an interesting earful about why it’s almost universally hated. Those who seem less bothered or maniacally enjoy this noise are either special or a special breed of crazy— crazy being the ones who do this on purpose!

Where does the sound of nails on a chalkboard rank on your awful noise list? Do you have a high tolerance for terrible sounds? What’s worse than the chalkboard scenario for you?

Sources:
Time
Live Science