Sometimes, the sense of hearing is a mixed blessing. Think of the joy you feel while listening to your favorite music. Consider the comforts of a heart-to-heart talk with a parent or close pal. On the other hand, imagine the horrible noise of an ambulance screaming along the highway. Or the terror of an unexpected sound when you are almost asleep at night. Joy, comfort, pain, and terror—you experience them all through your ears.
Your ears can hear a huge variety of sounds. They range from the bone-shaking noise of a jackhammer to the whisper of wind in a tree. But there are sounds that you can’t hear, like a dog whistle. And you never hear most of the sounds your own body makes: joints creaking, stomach churning, eyelids fluttering. Your body blocks out its own sounds so you can focus on what your brain is really interested in.
