The Miracle of Hearing

Eeeeee! Do you ever hear a high-pitched whine? You can’t see what is making the sound, but you hear it. It sounds as if it’s coming from inside your ear—and it is! That sound is one of your sensory hair cells dying. (Don’t worry, you have plenty more.) When I hear it, it reminds me how amazingly God created my ears to be able to process sounds.

Most of us can see the outer part of our ears when we look in a mirror. God created its shape to funnel sound into our inner ear. We help our outer ears funnel sound when we cup our ears to hear someone better.

Once a sound reaches the middle and inner parts of our ears, things get really interesting. God created sound to make things vibrate. Your middle ear contains an eardrum with a membrane that vibrates when sound waves hit it. You can model this by stretching a balloon over a can opening like a drum and sprinkling sugar on it. When you ring a tuning fork near the can, the sugar will vibrate with the tuning fork sound. Your eardrum, also called the tympanic membrane, makes three tiny bones in your middle ear vibrate. These three small bones, called ossicles, are so small they can be placed together on a penny! The last bone transfers vibrations to an oval window on your inner ear.

Your inner ear, or cochlea, is a fluid-filled chamber shaped like a snail shell. Inside the cochlea are tiny hairs called cilia. Vibrations from the oval window go through the cochlear fluid, hitting cilia along the way. Hairs near the opening of the cochlea detect high sounds, and hairs near the center detect low sounds. When these hair cells die, you hear that high-pitched sound.

But so far God’s design for your ear has just transferred vibrations to a fluid that causes your sensory hair cells to vibrate. More has to happen in order for you to hear.

Each time a vibration hits a cilium (a single hair), it transfers an electrical message to the brain telling the brain you hear something. Your brain then changes these electrical signals into something you will recognize. Your brain decodes these electrical signals into music, birdsong, or your teacher’s words. Amazing!

The last step of God’s design for your ear is understanding the messages sounds give you. But this has nothing to do with your ear. This has to do with your heart. Jesus said, “Whoever has ears, let them hear,” seven times in the gospels. Jesus wasn’t referring to the physical way your body hears things—sound waves to eardrums to ossicles to cochlea to cilia to your brain. Jesus was referring to the “ears” of your heart. Do you understand that Jesus loves you and wants you to live your life differently for him? The way our ears work is amazing, but Jesus’ love for you and the way he wants you to live your life for him are even more amazing!