^They look a lot weirder with no human ears if it isn't covered with hair. As for how they work - well, they clearly work as ears, at least in kemono friends - you see them twitching at sounds etc. But you also can't have holes in the tops of their skulls - there is no room on the top for ear canals or all the inner ear stuff unless you have like 30% of their brains missing lol. So lets just say their animal ears work by magic.