A previous study, which earned an Ig Nobel Prize in 2006, found that frequencies in the middle of the audio range were the most irritating, and these frequencies are very similar to the warning cries of chimpanzees. Those researchers speculated that our reactions to these sounds have their roots in predator-fleeing instincts from our evolutionary past.
You might not have heard of “ grima ”, but you have almost certainly felt it . Spanish speakers say they feel grima when they hear the sound of fingernails on a blackboard, or a knife scratching a plate. Now psychologists are suggesting it should be considered as distinct from other emotions.