Science Determines Why You Hate the Sound of Nails on a Chalkboard


At every minute of every day, it seems, scientists are busily working to cure cancer and save the environment and make better robots who can do our jobs for us, and also to figure out why we hate the noise fingernails scraping a chalkboard so much. Fortunately for those breathlessly anticipating that last bit of information, a group of researchers from the University of Cologne and the University of Austria have uncovered the reason, or what they think is the reason, because, well, you can’t be too sure about these things until years and years of study have been completed, and even then, who the hell knows? But what they think is that the sound of fingernails on a chalkboard is so abhorrent to humans because of HUMAN EARS. Yep. It’s your ears’ fault.

Specifically, it’s your ear’s shape that makes you hate chalkboard nail scrapes. It amplifies the sound. Which is, at least in our view, is sort of the purpose of ears. But then we’re not scientists.

What we want to know, science, is why a person would ever actually want to scrape their nails on the chalkboard. Who was the patient zero of this grand idea? Because, it’s terrible! It’s not even fun!

Alas, in order to conduct this experiment and provide this public service, the scientists had to play a lot of fingernail-scraping clips for the poor souls co-opted into their experiment.

Half the study subjects were told what the sounds were; the other half thought that they were listening to selections from contemporary music [ed: Ha.]. Scientists asked the participants to rate each sound’s unpleasantness, and also gauged the subjects’ stress responses to the noises by measuring their blood pressure, heart rate, and skin conductivity (a measure of sweating).

With the awful chalkboard noises, scientists found that when they removed pitch information in the range of 2000 hertz and 4000 hertz, at the peak of human hearing, from the recordings, the noises were considered more pleasant than in the other versions. “One explanation for people’s sensitivity to this band of frequencies is that sounds in this range are amplified due to the anatomy of the ear canal; they are literally louder to us than other sounds are. So chalkboard squeak may be irksome because the most obnoxious elements of the sound sit right in the sweet spot of human hearing.”

We hate the chalkboard squeak because God wants us to hate it, in essence. And, we hate it more if we KNOW it’s a chalkboard squeak.

Our takeaway: Stay away from chalkboards. They are evil, and they don’t like you very much, either.

Ear Anatomy May Amplify Irritating Tones of Chalkboard Squeak [NewsWise]


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