[maxov]

Sure, that seems reasonable, although likely a different mechanism than the one I’m talking about, which seems to come from early life language acquisition. I think when people discuss absolute pitch, this is the type they have in mind, because using tinnitus is still using a reference tone. I believe there were early theories for absolute pitch around this idea (that those with absolute pitch used tinnitus to help them identify tones), but they have been made obsolete by more recent knowledge.

I have tinnitus as well, and while it is very mild, I am surprised at the idea it can be ‘stable’ enough to form a basis for absolute pitch. Most of the time I don’t experience it as a pitch layered on top of all other sounds. Even if I focus on it, it doesn’t feel like a sound that can be given a clear singular tone, if that makes sense. I do know experience of tinnitus varies, so perhaps there are forms that are more capable.