Interesting Things About Cat Ears

Cats’ ears are pretty similar to those of other mammals and share the same three structural areas: the outer ear, middle ear, and inner ear. The outer ear is made up of the pinna (that’s the external triangular part you can see on top of their heads, and what we usually think of when we talk about their ears) and the ear canal. The pinna’s job is to capture sound waves and funnel them down the ear canal to the middle ear. Cats’ pinnae are mobile, and they can turn and move them independently. “Cats have a lot of muscle control over their ear,” says Dr. George Strain.

For all their similarities to other mammalian ears, cat ears do have some anatomical differences, including one that can frustrate veterinarians. “One of the things that we struggle with in patients who have middle ear infections is that cats have a septum, like a bony shelf, that separates their middle ear into two compartments,” says Dr. Christine Cain, the section chief of dermatology and allergy at the University of Pennsylvania School of Veterinary Medicine. “That can make it really difficult for us to resolve their middle ear infections because there’s a compartment that you just can’t get to very easily.”

You might have noticed cats have folds of skin forming what look like small slits on the outer bases of their pinnae. These little structures are formally called the cutaneous marginal pouches, but are more commonly known as Henry’s pockets. Veterinarians are unsure what purpose the pockets serve, if any.

Most cat owners can tell you, anecdotally, that their pet has a very good sense of hearing. But just how good is it? “Cats hear lower frequencies and higher frequencies than dogs and people do,” Strain says. A cat’s hearing range is approximately 45hz to 64khz, compared to 67hz to 45khz in dogs. While the range of human hearing is usually pegged at 20hz to 20khz, Strain says 64hz to 23khz is a better representation.

Some cats have four ears (or at least four outer ears, with extra pinnae behind their normal pinnae). The additional ears are the result of a genetic mutation. “They also have some other abnormalities,” Cain says. “Their eyes are smaller and they have a little bit of an underbite, too.”

Giving a hearing test to a cat is sometimes tricky, but it can be done. Behavioral tests where veterinarians make a noise and look for responses have several problems, Strain says. They can’t detect unilateral deafness, for example, and it’s not uncommon for cats to be stressed out and unresponsive during the tests.

Cats are an altricial species, which means that for some time after birth, they’re relatively immobile and not all of their sensory systems are working at their full potential. Strain says cats are born with their ear canals sealed and their auditory systems immature. “They respond to sounds as soon as the ear canal opens, and their hearing threshold will get better—that is, they can hear softer and softer sounds—in the several weeks after that,” he says.

Collected : http://www.petmd.com/cat/care/cat-facts-10-interesting-things-about-cat-ears?utm_source=outbrain&utm_medium=PaidContent&utm_campaign=petMD-Cat-Care&utm_content=Cat+Facts%3A+10+Interesting+Things+About+Cat+Ears