Conductive Hearing Loss - This type of hearing loss occurs when sound is not conducted effeciently through the ear canal, eardrum, or tiny bones of the middle ear. Conductive losses reduce the loudness of sound that is heard. Frequent colds, allergies, or certain childhood illnesses may cause a blockage due to fluid in the middle ear and may lead to temporary hearing loss or even permanent damage. Buildup of earwax, inflamation or infection in the ear canal, heredity, and birth defects may also cause conductive hearing loss.
Sensorineural Hearing Loss - This type of hearing loss occurs when there is damage to the inner ear or to the pathways from the inner ear to the brain. Sensorineural losses usually involve both a reduction in sound level and in speech understanding. The aging process, heredity, birth defects, certain drugs, head injury, tumors, and exposure to loud noise can all lead to this type of hearing loss.
Mixed Hearing Loss - This type of hearing loss is a combination of conductive and sensorineural types. For example, a child with a hereditary sensorineural hearing loss may get an ear infection or other ear disease.
Central Hearing Loss - This type of hearing loss occurs when the auditory centers are affected by injury, disease, tumor, heredity, or unknown causes. Loudness of sound in not necessarily affected, but understanding speech is.
|Today's hearing aid batteries are "zinc-air." Because batteries are air-activated, a factory-sealed sticker keeps them "inactive" until you remove the sticker. Once the sticker is removed from the back of the battery, oxygen in the air contacts the zinc within the battery, and the battery is "turned-on." Placing the sticker back on the battery will NOT prolong its life. Since many of today's automatic hearing aids do not have "off" switches, removing the battery at night assures that the device is turned off. Zinc-air batteries have a "shelf life" of up th three years when stored in a cool, dry environment. Storing zinc-air batteries in the refrigerator has no beneficial effect on the shelf life, in fact, quite the opposite may happen. The cold air may actually form little water particles under the sticker,. Water is made of oxygen and hydrogen. If the water vapor creeps under the sticker, the oxygen may contact the zinc, and the battery could be totally discharged by the time you peel off the sticker! Therefore, the best place to store batteries is in a cool, dry place, like the back of your sock drawer, not in the fridge!