The ears have it
Cats have amazing auditory anatomy. With 32 muscles in the pinna, or outer ear, they can twitch their ears any which way — forward, backward and to the side — to capture even the slightest noises. Sound waves travel through the ear canal to the eardrum in the middle ear. The eardrum vibrates in response to the sound waves, and those vibrations are transmitted by the auditory ossicles (three tiny bones known as the hammer, anvil and stirrup) into the inner ear. There, nerve endings in the cochlea, the organ of hearing, pass the vibrations on to the brain, which translates them into sounds.