Should work for the op though, since its just looking for something comparable to “blind as a bat” after all. Maybe “Deaf as an eagle”? No more deaf than echolocating bats are blind but similarly less reliant on that sense due to the excellence of another.
Nah, needs the alliteration. “Deaf as a dinosaur”? Yeah, not really deaf either and depends on the species but again as deaf as bats are blind …