What sorts of outer ear problems may affect hearing?

Anything that completely occludes the ear canal can cause hearing loss. Impaction with cerumen (wax) is common. It is frequently due to the use of cotton tipped swabs in attempts to clean the ear. The ear has a natural self-cleaning mechanism. Ear skin normally sheds from the inside out. If you place a drop of ink on the eardrum and wait a few weeks, it will turn up near the opening of the ear. The ear canal is also shaped like a funnel, with the narrow end near the eardrum. Cotton swabs generally push wax deeper into the ear than it normally is (wax forms only in the outer segment of the ear canal), and packs it into a mass. As long as there is even a pinhole opening in the packed wax, hearing is usually good. However, when occlusion by wax is complete, a substantial hearing loss develops. This can be cured easily by removing wax either by using specially designed instruments, or irrigation with water. There are many over the counter wax control preparations but they often cause maceration of the skin, and consequent external ear infections. Many other problems can cause ear canal occlusion and hearing loss. They include infections with swelling that shuts the ear canal, foreign bodies in the ear, trauma, birth defects, tumors (including cancer) and other causes. Resulting hearing loss is conductive. That is, it interfered with sound conduction and is generally correctable. It causes decrease in volume but does not generally produce distortion.