The natural diminishment of hearing ability that occurs with aging. HEARING LOSS affects both ears, is sensorineural, and progresses in a predictable pattern, beginning with sounds in the high frequency range (2,000 Hz to 4,000 Hz). Researchers do not know the precise mechanisms through which presbycusis takes place, though most believe it occurs through a cumulative loss of cells from the inner EAR, the NERVE pathways to the BRAIN, and within the brain itself. Many factors influence the rate of progression. One third of adults between age 65 and 74 and half of those beyond age 74 have age-related hearing loss. Health conditions that affect blood circulation and nerve function, such as ATHEROSCLEROSIS and DIABETES, intensify the effects of age-related changes. Noise exposure can exacerbate the rate and nature of hearing loss. Older adults also are more likely to take medications that have ototoxic side effects, such as loop diuretics and certain antihypertensive medications.
Early indications of presbycusis, which may become apparent when a person is in his or her late 50s or early 60s, include difficulty hearing certain sounds and words, because the frequency range that is lost is that of conversation. Turning up the volume on the television and perceptions that other people are mumbling are also signs of hearing loss. There are no known methods for preventing presbycusis. Hearing aids often improve hearing ability, though the progressive loss of hearing may eventually exceed the capability of the HEARING AID.