The Hearing Organ
Have you ever whispered in someone’s ear? Have you ever yelled in someone’s ear? How do we hear each other? How do we hear our teachers, our parents, or the television? As objects move or interact with other objects, they cause the air to vibrate. Think of a swimming pool. What happens if you jump in? First, you make a big splash, followed by a series of ripples. The harder you jump,the bigger your ripples will be.
The air of our atmosphere works in much the same way as a swimming pool. Even though we cannot see the ripples, every time we move they go traveling through the air. Some of these ripples, or vibrations, reach our ears. Inside of your ear is a thin tissue known as the tympanum, or eardrum. The vibrations in the air cause your eardrum to begin vibrating. Behind your eardrum are three tiny bones called the hammer, the anvil, and the stirrup. As your eardrum begins to vibrate, so do these tiny bones. The last of these bones, the stirrup, transmits these vibrations into the fluid-filled cochlea. This causes tiny hairs within the cochlea to vibrate. The vibration of these hairs is converted into electrical impulses, which are then transmitted to the brain for interpretation.