The Anatomy Of The Ear

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The anatomy of the ear consists of three sections: the outer ear, middle ear, and the inner ear.
The outer ear comprises the auricle and the external auditory canal. The auricle is the part we can see. It has the job of collecting sound waves and conducting them to the canal. The external auditory canal leads from the auricle to the eardrum. Special glands can pump wax into the canal to trap specks of dirt or insects, and a few hairs are present to help.
The middle ear is a small cavity. In many respects it is like a narrow oblong house. The eardrum forms its outer wall. The inner wall is mainly bone but it has two windows - the oval window, and the round window. It also has two openings, the Eustachian tube from the nose, and a link with air cells in the skull.
The Eustachian tube connects the middle ear to the outside air. This should ensure that the air pressure is the same on each side of the eardrum. However, if you have a cold, the tube can block and the unequal pressure can cause temporary deafness. The temporary deafness or "blocked ears" experienced at high altitudes is also due to a pressure difference.
The Eustachian tube usually opens when you chew, swallow, yawn etc., which activates the muscles around the tube. So at high altitudes when the atmospheric pressure is low, it requires a lot of swallowing-type action to open the Eustachian tube, release the air, and thereby equalize the pressure each side of the eardrum.
There are three very important bones in the middle ear. They are called the malleus (or hammer bone), the incus (or anvil bone) and the stapes (or stirrup bone).
The handle of the 'hammer' is firmly attached to the eardrum, and the stapes is connected to the oval window of the inner ear.
Sound waves make the eardrum vibrate. The three bones of the middle ear then transfer the sound to the inner ear by vibrating themselves.
The oval window separates the middle ear from the inner ear. Inside the...