The Outer Ear:
The outer ear consists of the visible part of our ear (the auricle) and the ear canal. What we call 'noises' are actually just 'sound waves' which are transmitted by the air. These sound waves are collected and guided through the ear canal to the eardrum. The eardrum is a flexible, circular membrane that vibrates when sound waves strike it.
The Middle Ear:
The middle ear is an air-filled space separated from the outer ear by the eardrum. In the middle ear are three tiny bones: malleus, incus, and stapes, collectively known as the ossicles.These form a bridge from the eardrum to the inner ear. The ossicles also vibrate in response to movements of the eardrum and in doing so, amplify and relay the sound to the inner ear via the oval window.
The Inner Ear:
The inner ear, or technically the cochlea, is similar in shape to a snail shell. It contains several membranes filled with fluids. When the tiny bones in the ear (ossicles) conduct sounds to the oval window, the fluid begins to move, thus stimulating the minute hearing nerve cells (hair cells) inside the cochlea. These hair cells send electrical impulses through the auditory nerve to the brain where it will be interpreted as sound.