Science Explains Why Nails on Chalkboards Annoy

Uggh, just writing about this is giving us goosebumps.

In what was surely one of the most annoying studies to have ever been undertaken, German and Austrian researchers have uncovered just why the sound of nails on a chalkboard is so grating. The researchers played the sound of fingernails on chalkboards to listeners, but would alter which frequencies were coming across loudest. The subjects responded the worst when the frequencies between 2,000 and 4,000 hertz were amplified the most. Human speech can range anywhere from 150 hz to 7,500 hz, but that middle range appears to get magnified by the shape of our ear canals. When the frequencies between 2,000 and 4,000 were turned down, the subjects reported far less unpleasantness than when those frequencies had been turned up. The researchers hope to use their findings to determine ways to get rid of ear-piercing sounds found in machinery, vacuum cleaners, and hopefully, the brakes on TTC subway cars.