Certain sounds - a famous example being the sound of fingernails scraping a chalkboard - illicit strong feelings of discomfort, and even repulsion, in most people from most cultures across the world.

(In Spanish it's called 'Grima' , but there's no equivalent word in English)

The effect is so universal that it's thought to be an innate ('hard-wired') response of some kind - possibly linked to feelings of Disgustplugin-autotooltip__plain plugin-autotooltip_bigDisgust

Over the last 100 years or so, there has been a large volume of research into the human 'disgust' response.

See Wikipedia

Although there are (slight) cultural differences across the world's populations, it's currently regarded as a truly 'innate' (rather than learned).

Experiments have shown that such sounds can trigger the body's 'fight or flight' response - which acts as a primary self-defense mechanism

Note that because it's so prevalent and widespread, it's not thought of as a 'phobia' as such (see Misphonia link below )

There's currently no agreed explanation as to why this Grima effect exists, or what possible evolutionary advantages (if any) it may have (or have had in the past).

Possible (though unproven) theories include the ideas that the sounds may mimic harsh warning calls of our distant primate ancestors, or that the noises painfully overstimulate the mechanics and/or the psycho-acoustic pathways of the inner ear.

Further reading : Grima: A Distinct Emotion Concept?, Frontiers in Psychology 2017; 8: 131.

Also see : Misophoniaplugin-autotooltip__plain plugin-autotooltip_bigMisophonia

Misphonia is a distressing neuro-behavioral syndrome which involves decreased tolerance for sounds of certain types. Example noises include breathing, chewing, swallowing, clicking sounds, keyboard tapping, finger tapping, clock ticking, windshield wipers etc.