Earplugs can give you tinnitus because they provide almost complete silence, in which your brain can latch on to the tinniest pre-existing tinnitus sound that w

Earplugs can give you tinnitus because they provide almost complete silence, in which your brain can latch on to the tinniest pre-existing tinnitus sound that was already there (which is pretty common in the current era of hearing-damaging equipment and environments), but you didn't notice it before. Once the brain notices it, it's basically impossible to unhear it. That's my theory at least.