How does hearing occur?
The Ear and the Sense of Hearing
The organ for hearing sound is the ear. It is one of the most complex and useful organs in our body. Hearing sounds is all about vibrations. Vibrations cause sound waves. For instance, if you knock on your table, sound is produced as a result of vibrations from the impact. But the sound alone means nothing until we hear it, and our brains interpret what sound it is.
Here is the diagram of the entire hearing organ, The Ear.
The ear is made up of three sections. The outer ear consists of the earflap (also called the pinna or auricle), the outer ear canal and the eardrum. The middle ear houses our body’s three smallest bones, the ossicles. The inner ear consists of bony chambers called the cochlea and corti.
The pinna is like a funnel, which directs sound to the ear canal and unto the eardrum. The ear canal has wax in it that helps trap infections and particles from getting deeper into the more sensitive parts of the organ.
Sound waves travelling through the ear canal reach the eardrum and bounces off, setting the eardrum to vibrate too. This sets off more vibrations of the ossicles (the three small bones called Hammer, Anvil and Stirrup) inside of the middle ear.
The ossicles are connected to the cochlea. The cochlea is a long chamber, shaped like a garden snail, filled with a liquid. The chamber has a hair-like lining. As the vibrations travel through the liquid in the chamber, the tiny hairs are stimulated, picking up the vibration signals from the liquid and send them to a special part of the brain for interpretation. The entire process happens within millions of a second.
Powerful vibrations cause more activation of the hairs in the cochlea and the brain understands it as very loud noise. Extreme vibrations can break (rapture) the eardrum and ossicles, causing hearing loss. Even household noise like loud sound systems, lawn mowers and loud earphones can cause significant damage to the hearing organ. The ear is a very useful organ and you should take care of it by wearing sound-proof equipment when in very noisy environments.
Infections (often caused by bacteria introduced into the ear by sticking things into the ear), drugs and old age can all cause hearing loss.