Did you know that cats can hear sounds that even a dog cannot? We can hear 100,000 hertz as opposed to the dog’s range of 35,000 to 40,000 hertz. People pale in comparison hearing only 20,000 hertz. These two satellite dishes atop my head allow me to hear ultrasonic sound (which sounds cool, but just means sound beyond that of the limit of human hearing). My ears can rotate up to 180 degrees to help me locate and identify even the faintest of sounds, like a peep, squeak, or rustling of a mouse. This high sense of hearing is essential to our survival as we are great hunters. My cousins (both domestic and wild) also use it to hear the distress call of our cubs or kittens from a distance. I can pinpoint the origin of a sound from up to 3 feet away and can hear sounds from four to five times farther away than humans.
Our renown sense of balance is due to our ears, as the inner ear has tiny chambers and canals that are lined with millions of sensitive hairs and filled with fluid and floating crystals. Any sudden movement and those delicate hairs detect it through the fluid and crystals and send a message to our brain to position the body in response. If I lose my balance, my vestibular apparatus (the scientific name for all that inner ear structure) kicks in. I can tell which direction is up and spin to land on my feet. Together with my tail, which provides counterbalance, I can perform some amazing acrobatic moves.
Check out these resources for more information on cat ears and hearing.