The ear canal makes up almost a third of the human auditory system. It plays a key role in carrying sound vibrations from outside the ear to the brain. It is also essential in keeping the inner ear and brain free from dirt and bacteria. Ear infections and other problems in the ear canal need to be taken seriously because of its proximity to the brain.
The ear's canal is a small tube located in the middle ear that connects the outer ear to the inner ear. It travels from the outer ear to the eardrum. The average length of the canal is 26 mm (1.02 inches), with a diameter of 7 mm (about 0.25 inches). The actual size varies with each individual.
One function of this tube is to carry sound from the outer ear to the eardrum. Hearing may be impaired when problems occur within the canal. An over-production of wax can block the passage of sound to the eardrum. Ear infections cause the canal to swell, which can also affect hearing. Basically, anything that affects the canal can also cause hearing problems.
The lining of the canal produces ear wax. The primary function of ear wax is to line the skin of the canal. The wax protects the skin from infection with its bacteria-killing components. Its thick, sticky texture collects dirt and other foreign substances like fly paper collects flies, keeping the inner ear clean. Too much wax can cause hearing problems and should be removed by a physician if it becomes problematic.
The ear canal is particularly vulnerable to infection and problems. It is located inside the ear, but it is also open to bacteria from outside the ear. Like the nose and mouth, the ears are a popular place for children to stick their fingers, which are likely carrying a lot of bacteria and germs.
Ear infections are one of the most common problems that can occur in the ear canal. The skin lining the canal is susceptible to dermatitis, otherwise known as an allergic reaction. Ear fungus can develop, as well as a rare condition called ear myiasis, which is an infestation of maggots in the ear. Surgery within the ear can leave scar tissue, which can cause a narrowing of the canal, called stenosis. Stenosis can occur within the canal for any number of reasons, from scarring to birth defects.