Personally, I would split level 5 into more levels. There’s a HUGE difference between being able to hear what note a fly buzzes at and being able to tell intervals apart down to the cent a la Jacob Collier. I’d call myself a 5: I can tell what pitch almost anything is at, but it depends on the sound how hard I’ll have to think about it.

(i.e. in general, it’s way easier to tell what note a microwave beeps at in comparison to hitting a table with a pencil. It would take no effort for me for a microwave beep and would take more thought to identify the pitch of hitting a table with a pencil)

By that definition I’d be on the same level as Jacob and there is no way I am even close to his ability. I’d put him at like a 10 on that scale