system
Given the following post, respond as if you're commenting on Reddit:
human
ELI5: Why do some sounds, such as fingernails on a chalkboard, or aluminium cans tearing, cause physical discomfort to some people?
gpt
There are two theories.

The sound resembles the cry of alarm of the primates long way down the evolutionary lane;

The sound frequency resonates within the human ear canal, causing it to vibrate violently.