THE EAR

THE EAR
The ears are the organs of hearing. They are two in number. They are incharge of collecting sounds, processing them, and sending sound signals to the brain. Not only that, but the ears also help us to keep our balance.

The ear is made up of three different sections: the outer ear, middle ear and inner ear. These parts all work together so that we can hear and process sounds.

THE OUTER EAR
The pinna or earlobe (auricle) is the outer part of the ear. It is the part that we can see. The main job of the pinna is to collect sounds. The outer ear also includes the ear canal, where wax is produced. The ear wax protects the canal by fighting infections if they enter the ear canal. Sounds from the pinna are conveyed to the ear canal or hearing canal, which is later sent to the final part of the outer ear-the eardrum.

THE MIDDLE EAR

This part of the ear consists of the three little bones: the hammer, anvil and stirrup. They are the tiniest and most delicate bones in the entire body. They are referred to as ossicles.

After sound waves leave the outer ear, they make their way to the middle ear. The job of the three bones is to amplify or speed up the vibrations, and deliver them to the inner ear.

THE INNER EAR
This section of the ear consists of a coiled tube called the cochlea, which is filled with liquid. It also contains tiny cells covered in tiny hairs. The cochlea is set in motion (like a wave) when the three bones pass on the vibration to it. The last little bone in the middle ear (stirrup) rests on the cochlea. When sound reaches the cochlea, the vibrations (sound) cause the hairs on the cells to move, creating nerve signals. The signals are sent to the auditory nerve, (which forms part of the inner ear). This nerve takes sound signals to the brain, where the signals are decoded or interpreted as sounds.

The semicicular canals which are also found in the inner ear, are three small loops above the cochlea. These help us to keep our balance.

HOW WE HEAR SOUNDS (in brief) (1) How we hear (Part 2)

When objects in the environment vibrate, they produce sounds. These sounds are picked up by the pinna. The pinna passes sound signals along the hearing canal. At the end of the canal is the eardrum. When sound hit the eardrum, it causes it to vibrate. Because the first bone (hammer) rests on the eardrum, the vibration is passed on to the bones and conveyed to the other two. These bones amplify or speed up the vibrations.

The last bone (stirrup) which fits into a window in the cochlea, allows the vibrations to be passed on to the cochlea. The vibration of the cochlea changes the sounds into nerve signals, which are later carried to the brain by the auditory nerve. In the brain, it is decoded or interpreted.

Culminating activity

1. A little activity for you.

2. Complete this quiz correctly.
3. Name the numbered parts of the ear.
4.Use the mouse to label the ear correctly.

EAR LOSS

The inability to hear sounds is called deafness.

There are a number of factors that can cause loss of hearing. Some of these include:

(a) too much continuous noise (noise pollution)

(b) damaged ear parts

(c) infection of ear

To prevent ear loss, we need to :

a. do not swim in dirty water

b. do not allow people to shout in your ears

c. avoid listening to loud music

d. use ear muffs if you work in noisy areas

Hearing aids can be used to help partially deaf persons.