Good question, hopefully someone will come along and answer it for us!

Or, well, I assumed it was, until I tried to find the answer online.

My current answer: “I have no idea.”

I’m not sure that I have actually found the answer, but this is what I have so far:

http://www.fabcats.org/earproblems.html

That site shows feline ear anatomy and has a nice description/image of external ear structure.

Though I’m not seeing an exact name for the “little pockets” in cats ears, the pinna is the name of the rigid, triagular part of the ear and indicates that the outer ear is made up of cartilage.

I suspect that the function of the folds, pockets, and ridges inside of a cat ear are similar to those in a human ear: to enhance auditory functions such as amplification and sound identification.

(human ear info from: http://www.neurophys.wisc.edu/~ychen/textbook/external_ear.html)

I hope this helps…. if you need more info, just let me know, and I’ll do my best to track it down =)

I asked my vet (the Most Wonderful Vet in the World, by the way!)....

She said it’s called the “tragus” and that her best guess as to its function is to “give flexibility to the ear” (so that it can, for example, be folded down and back).

my guess is that the large part of the ear is like the radar, since theyre always moving around to the direction of sound and the pockets are for storage of sound while the other parts of the ears are looking for new sounds

But I always thought it was a deformity in my cat. I never really paid attention to other cats’ ears.

When I mentioned to my then-housemate (DVM, PhD in animal phys., working on her post-doc at Cornell U.), she thought that was the funniest thing she ever heard. It was then I found out every cat’s ears is like that. But she never told me why.