How the ear works
To better understand what your child is experiencing, let's take a closer look at the different parts of the ear and how they function.
The ear is made up of three main parts: the outer ear, the middle ear and the inner ear.
The outer ear
The visible part of the outer ear is called the auricle or pinna (a). The pinna collects sound waves and channels them into the ear canal (b), in which the sound is amplified. The sound waves then travel toward a flexible, oval membrane at the end of the ear canal. This is the eardrum (c). When the sound waves reach the eardrum, they make it vibrate - just like when hitting a real drum.
The middle ear
The vibrations from the eardrum then pass into the middle ear, which contains three tiny bones: the hammer (d), the anvil (e) and the stirrup (f). These bones are the tiniest in the human body. The airborne sound vibrations then pass through a membrane called the oval window into the fluid of the inner ear. A tube at the bottom of the middle ear, called the Eustachian tube (g), connects to the back of the nose to control the air pressure.
The inner ear
When the sound waves reach the inner ear they enter the cochlea (h)- a system of tubes shaped like the shell of a snail. The cochlea is filled with a watery liquid, which moves in response to vibrations within the oval window. As the fluid moves, 25,000 tiny nerve endings are set in motion. They transform the movements into electrical impulses, which travel along the auditory nerve to the brain. The brain then interprets these signals - and that is how we hear.
