Learn why nails on a chalkboard are irritating.

Why do most people cringe at the sound of fingernails scraping on a chalkboard?

In 2011, musicologists from Austria and Germany conducted a study with 24 people, playing them a series of sounds and asking them to rate the sounds from most pleasant to most unpleasant. All the sounds were modified versions of nails on a chalkboard.

The study revealed that frequencies between 2 thousand and 4 thousand Hertz cause an adverse reaction in people.

Removing the frequencies in that range made the sounds more tolerable.

Further research in 2012 showed there are two parts of sound that cause aversion in people, namely sharpness, or frequencies that are too high, and roughness, which is the fluctuation of frequency intensity.

The aversion to high frequencies might reflect that fact that hearing loss can occur from exposure to those sounds.

The randomness of the sound of nails on a chalkboard may also contribute to people’s dislike of that kind of screeching noise.

Other scientists suggest that our aversion is because the screeches sound similar to a scream – a noise we are conditioned to fear or dislike.