Introducing the Ear
Most people are very familiar with their external ears because they are visible and easily accessible. However, the internal structures of ears and the associated hearing apparatus are much more obscure. The external ear only acts as a physical siphon for sounds. It funnels the sound waves and allows the vibration to be passed into the eardrum, where its vibration is subsequently transformed into nerve signals that can be interpreted by the brain. What makes hearing possible is this intricate system of tubes and ducts, some of which are hollow and some that are filled with fluid. The presence of infection disrupts this delicate mechanism. Ultimately, what pediatricians and parents are most concerned about is preserving normal functionality of hearing.
Ear Anatomy
The anatomy of the ear is divided into three major sections. The external ear is the part of the ear that you can see, extending all the way to the eardrum. The middle ear resides between the eardrum and the inner ear, where the nerves responsible for hearing are located. The middle ear is mostly filled with air, whereas the inner ear is mostly filled with fluid.
The inner structure of the ear is truly a work of wonder. Along with the small tubes that are designed to transmit sound waves, there is a complex drainage system network that allows certain internal structures of the ear to be filled with air and at a pressure equal to the outside environment. Without such a system, the hearing apparatus could not function properly.
In order to maintain this equal pressure, the internal air pocket is connected to the throat via a small duct. This duct is called the Eustachian tube.
Essential
Given that the external ear and the middle ear are separated by a physical barrier (the eardrum), it is virtually impossible to get a middle ear infection from swimming. Swimmers can get swimmer's ear, which is an infection of the external ear. This has nothing to do with the typical ear infection, which is an infection of the middle ear.
The Eustachian tube is very small, and it can open and close its connection to the throat at will. Most of the time, the duct is sealed off to prevent food and mucus from entering the air pocket inside the ear. It opens briefly when you open your jaw, swallow, or yawn.
Individual Differences
Just as all people have unique facial features, the internal structure of the ear is also quite varied. The shape of the Eustachian tube that equalizes the pressure inside the ear is different in everyone. Some people have long and narrow tubes, while others have thick and short ones. Depending on the configuration of the tube, some tubes are more likely to stay open than others. The long and narrow ones tend to get clogged with mucus more easily.
Fact
During air travel, the cabin pressure of the airplane is somewhat lower than the atmospheric pressure at sea level. Consequently, the Eustachian tube must open briefly to balance the pressure difference inside the middle ear and the cabin. It is a good idea to give your infant something to drink during these times because she cannot voluntarily yawn or swallow to open up her Eustachian tube.
If the tube becomes obstructed, fluid tends to accumulate inside the middle ear, an area normally filled with air. Once this fluid settles into the middle ear, the risk of infection goes way up. The fact that some people's Eustachian tubes are more easily blocked than others is the reason why some children tend to suffer from more frequent ear infections. In addition, children tend to have smaller tubes, a configuration that makes them more likely to get clogged with mucus when they have a cold. That is the reason why children get ear infections more often than adults.
