I think this question is on topic. At least I hope it is. I would like to know if there is anyone who can improvise who can't hear music (or anything else) in their head.

I can play simple melodies by ear because I can feel where the next note should be (I can't explain what that means), but I can't hear anything at all in my head, and consequently, I can't play anything complicated by ear, and I can't improvise.

I can't see much of anything in my head either, so to the extent that I can read music, I can't use memory of the written music to help me remember more complicated pieces.

Am I a freak or are there other people out there like me? And can any of them improvise or play complicated pieces by ear?