Hearing Loss - Causes and symptoms

Some possible causes and symptoms of hearing loss at each of the above stages are as follows:

• External ear. The auditory canal may become blocked with ear wax, foreign objects, infection, or a tumor. A tumor is a mass of cells that forms a lump somewhere in the body. This blockage prevents all or some of a group of sound waves from passing down the auditory canal.
• Middle ear. The tympanic membrane and ossicles can be damaged by injury or infection. A sharp object inserted into the ear can break the membrane. A blow to the head may damage the membrane or the ossicles. High water pressure caused by a deep-sea dive can also damage the middle ear. Infection of the middle ear may be caused when fluids from the throat pass down the Eustachian (pronounced you-STAY-shee-un) tube into the middle ear. The Eustachian tube connects the middle ear with the back of the throat. A disease called otosclerosis (pronounced oh-toe-skle-RO-suss) can cause the ossicles to bind to each other. When that happens, they are not able to vibrate properly.
• Inner ear. The primary cause of sensory hearing loss is exposure to loud noise. By some estimates, more than one million people have hearing problems for this reason. Exposure to loud noise may be caused by listening to loud music or working at a job where loud sounds are produced. Sensory hearing loss also occurs as a natural part of aging. About a third of the people over the age of sixty-five have partial or complete hearing loss. Infections of the inner ear and brain can also cause hearing loss. Certain drugs, including some common antibiotics, may damage the inner ear or auditory nerve. Finally, damage to the brain, such as stroke (see stroke entry) or multiple sclerosis (see multiple sclerosis entry), can cause hearing loss.