Is there a worse sound than fingernails being scraped on a chalkboard? For most people, including me, the answer would be a resounding no. And if it doesn’t make you shudder and cringe then you might want to seek help because there is possibly something wrong with you.
That being said, after all these years of knowing HOW awful the sound of fingernails on a chalkboard is many of us have no idea WHY it bothers us so much.
Until now.
Thanks to, you guessed it, SCIENCE, we have the answer.
According to a study conducted by researchers from the University of Cologne and the University of Vienna they believe that it has to do with the shape of our ears.
In other words, our ears our built to amplify sound and the sound of fingernails on a chalkboard produce a frequency that is very unpleasant.
Half the study subjects were told what the sounds were; the other half thought that they were listening to selections from contemporary music. 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).
The human ear is known to be particularly sensitive to pitches in the mid- to low-level range of frequencies, between 2000 hertz and 4000 hertz, which is the peak of human hearing. It turns out that when scientists removed all the pitch information in this range from the audio recordings, the study participants rated the noises as more pleasant than other versions of the sounds. 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.
Sure, these universities could have been working on cures for diseases or creating new technology instead of trying to figure this out, but really, we all wanted to know the answer to this didn’t we? And now we do (we think).
[Newswise]
H/T LadBible; Fingernail on a chalkboard image by Shutterstock