How Do We Hear?

Hearing involves a complex chain reaction within the ear:

• Sound creates vibrations in the air somewhat similar to the rippling waves created when a stone is thrown into a pond.
• The outer-ear "trumpet" collects these sound waves, and they are funneled down the external ear canal to the eardrum.
• As the sound waves strike the eardrum, they cause it to vibrate.
• The vibrations are transmitted through the middle ear over the bony bridge formed by the hammer, anvil, and stirrup.
• These vibrations, in turn, cause the membranes over the openings to the inner ear to vibrate, causing the fluid in the inner ear to be set in motion.
• The motion of the fluid in the inner ear excites the nerve cells in the organ of Corti , producing electrochemical impulses that are gathered together and transmitted to the brain along the acoustic nerve .
• As the impulses reach the brain, we experience the sensation of hearing. We can understand conversations, listen to music, birds, hear clocks tick...