CAT'S MIND-Communication

Your Cat's Sense of Hearing
Hearing is an important part of a cat's ability to hunt and fulfill his design as nature's perfect predator. It all begins with the cat's outer ear, or pinna, which sits on top of the cat's head. The outer ear is controlled by about 30 different muscles, which enable the cat to independently rotate each ear180 degrees, and position one ear or both facing any sound the cat detects. The shape of the ear is designed to funnel sound down to the middle ear, where the tympanic membrane and three small bones called auditory ossicles transmit vibrations into the inner ear. The middle ear also contains a canal called the eustachian tube that helps to equalize pressure in the ear. Within the inner ear is a curved bone, the cochlea, where the actual hearing mechanism is located -- called the organ of Corti. It is here that small, sensitive hairs pick up sound vibrations and send them through the auditory nerve to the brain.

Each part of a cat's ear, working together, gives the cat superb high-frequency hearing. Humans can hear frequencies from about 20 hertz to 20 kilohertz, dogs from about 20 hertz to 40 kilohertz, and cats from about 30 hertz to 60 kilohertz. "Cats are capable of hearing the very high pitch of high-frequency sounds that you or I can't detect," says Eric Christensen DVM, a consultant with the Cornell Feline Health Center. "The classic example of that would be noises from kittens or noises that a prey species like a mouse or another small mammal might make." Cats also have an incredible ability to localize sounds. They can hear and differentiate sounds three feet away whose sources are only three inches apart.

Hearing is a large part of a cat's life, and Christensen says it is important to try to shield cats from loud, high-pitch noises such as sirens, which can greatly disturb them. It is also important to take sound into account when playing with cats. There are several toys on the market that mimic the sound of prey species to entice cats to play with them.