I've seen people suggest inner ears, but never deaf ears. These would be in the ear slot and be auto-unlocked. Weak ears would give 1 hearing and deaf ears would give... maybe a boost on some other sense? For desings, I think the weak ears would look like normal ears but be pointing at different directions, because the nicheling is trying to hear better. For deaf ears - having one of them be a bit floppy would just simply be adorable (and also it would help to tell them apart them from