@skylark yes I have talked about this before with my friends and family (another sound that I dislike very much is styrofoam, though not as much as Velcro, which even thinking about it now makes me wince in pain) — and the only person who gets me is a close friend of mine who told me that he hates the sound of metal grating on metal and told me that his dad and brother share similar things, and he said something about overstimulation and autism, which runs in his family.