Cats usually have straight ears, which have a triangle shape. The size, exact shape and location vary from small to similar to normal size. There are also rare genetic defects, because of which the cat could have a second smaller pair of ears behind the normal ones. They are seemingly disfunctional. This rarely occuring evnet shold not be mistaken with the "four eared cat" of China - those are cats of persian kind,in which the fur within the ears gives the impression of a second pair of ears.