The Ear

What is the Ear?

The ear, which you probably already know, is a device that enables us to hear sounds. You also know that animals have two of these, which are usually located on either side of the head. The ear is made up of different components that work together to make sure your brain receives the vibrations that make up a sound.

Sound

Sound travels through solids, liquids, and gases as waves called sound waves. The sound waves travel, carrying sound energy(vibrations), which make up the sounds that someone hears.

 

How the Ear Works

Sound travels through the ear and eventually reaches the brain. There are three sections of the ear: The outer ear, the middle ear, and the inner ear. When sound enters, it reaches the outer ear first.

The Outer Ear

The Pinna

The pinna is the outermost and only visible part of the ear. The special shape of the pinna is made to direct sound waves further into the ear. By doing this, the pinna is making sure no sound gets lost. More sound waves reach the brain, and we hear better.

The Auditory Canal

After passing the pinna, the sound waves reach the auditory canal. The auditory canal is like a tube, and connects the pinna to the eardrum. Sound passes through the auditory canal until it reaches the next part of the outer ear.

The Eardrum

The eardrum, which is a flap of skin covering part of the ear, is at the end of the auditory canal. It is at the border of the outer ear and inner ear. The eardrum is extremely sensitive. Sound hitting the eardrum makes it vibrate. Because of its sensitivity, there are many things that protects the eardrum; some of these things are earwax, which makes sure dust or insects don’t enter the ear, and the curved shape of the auditory canal which makes it more difficult for insects to enter.

The vibrations made when sound hits the eardrum causes bones in the middle ear to vibrate. These vibrations reach the inner ear, and are sent to the brain. This is why the eardrum is an extremely important part of the ear. Without it, the sound vibrations would not reach further into the ear.

The Middle Ear

Bones

There are three bones located in the middle ear. These bones are the the hammer(malleus), anvil(incus), and the stirrup(stapes). The stirrup, which is the last bone for sound to reach, connects to the next part of the middle ear. Vibrations from the eardrum are sent to these bones, which make more vibrations. These vibrations continue to travel through the ear, reaching the oval window after leaving the stirrup.

The Eustachian  Tube

The eustachian tube is a tube located in the middle ear, with the other end connecting near the nose. The purpose of the eustachian tube is to make the air pressure inside the ear equal to the air pressure outside the ear. It also removes infection or unwanted debris in the ear.

The Cochlea

The cochlea is where sound waves are turned into electrical impulses which the brain can understand and convert into the sounds we hear all around us. The cochlea is filled with a liquid substance called perilymph. Vibrations from the oval wall are sent to the cochlea, allowing the perilymph to move freely and convert the sound waves into electrical impulses.

The Auditory Nerve

The auditory nerve is the nerve that connects the cochlea to the brain. The auditory nerve carries the electrical impulses made by the cochlea to the brain. Hair fibers located in the cochlea are connected to the auditory nerve. When these hair fibers move, electrical impulses are sent through the auditory nerve.

The Vestibule

The vestibule observes movements in our body and makes sure that we can keep our balance. The vestibule consists of three passages filled with a fluid. This fluid moves in response to our body’s movements. The passages also consist of hair fibers that sense the fluid’s movements and sends signals to the brain. The brain then uses these signals to keep balance.