Cats’ ears are similar to those of other mammals including the outer, middle, and inner ear. The outer ear consists of the pinna (the outer triangular part we see on top of their heads) and the ear canal. The pinna captures sound waves and funnels them down the ear canal to the middle ear. The middle ear contains the eardrum and tiny bones called ossicles which vibrate in response to sound waves, sending those vibrations to the inner ear which works to send electrical signals through the hearing nerve to the brain to be processed or interpreted. In addition, the inner ear contains the vestibular system that helps cats balance and orient themselves. The inner ear shares the function of hearing and balance. As a result, inner ear infection can affect both hearing and vestibular function with symptoms such as a head tilt or turning the body toward the side of the ear infection.
Cats, like dogs, have super-power hearing. In fact, cats’ hearing is actually better - they can distinguish sounds at a much higher range than dogs and also detect low-pitched sounds similarly to dogs. In addition, they can detect the tiniest variances in sound, just one-tenth of a tone apart, allowing them to figure out their prey animal’s size, putting people with perfect pitch to shame. Essentially, cats have some of the best hearing among domestic animals. This helps them to hear a wider range of sounds, giving them the ability to detect a wider range of prey species as well as the advantage of hearing and avoiding their own predators.
Cats have an incredible sense of balance, due to their specialized ears. Deep inside a cat’s ears are three canals full of fluid and lined with tiny hairs. As the fluid moves over the tiny hairs, a signal is sent to the cat’s brain indicating which way the cat’s moving. Another part called the vestibule, sends information that indicates whether the cat is upright, upside down, lying on their side, etc. The canals and vestibule are essential to a cat’s “righting reflex,” which allows them to land on their feet (most of the time) when they fall.
Cats’ ear canals have a self-cleaning ability and, lucky for us, don’t need our help to keep clean. If you notice any abnormal discharge, excessive ear wax, redness, or swelling in your cat's ear(s), you should contact your vet. Cats are sensitive to many products, and even ear cleaning products that are safe for dogs should not be used on cats because they can have serious reactions. Only use products recommended by your vet to clean your cat's ears.
Your cat’s ear temperature changes. Your cat’s ear temperature can help you determine their stress level. Like us, cats respond to fear and stress with elevated adrenaline and other changes in the body that cause increased energy production. Part of the energy produced increases a cat’s body temperature. Scientists have discovered that the temperature of a cat’s right ear (not the left ear) is associated with the amount of certain hormones released in response to stress and anxiety and could help indicate psychological stress.