Presbycusis and auditory brainstem responses: a review

Age-related hearing loss (ARHL) or presbycusis is a complex phenomenon consisting of elevation of the hearing levels as well as changes in the auditory processing. Although many adults retain good hearing as they age, hearing loss associated with ageing is common among elderly persons. There are a number of pathophysiological processes underlying age-related changes to functional components. Presbycusis is especially caused by cochlear degeneration, most pronounced in the basal cochlear coil. Causes include physiological ageing processes as well as endogenous or exogenous causes. The common form of hardness of hearing seen in old age is not due to physiological age-related changes, but rather to a complex sensorineural pattern of injury. In the industrial countries, two main exogenous causes are exposure to loud noise and obesity[2]. Some of the changes that occur in the aging auditory system may significantly influence the interpretation of the auditory brainstem responses (ABRs) in comparison with the ABRs of younger adults.