presbycusis (deafness of aging)

introduction

gradual age-related loss of hearing initially is a high tone hearing loss and is associated with difficulty in speech discrimination, particularly in noisy environments, and becomes a major impediment and socially isolating factor for many elderly persons
significant presbycusis can contribute to isolation, loss of self-esteem, depression, frustration, reduced quality of life and, possibly, dementia.
self-reported deafness in Australia rises steadily with age:
- 10% men aged 35-44yrs
- 20% men aged 45-54yrs
- 30% men aged 55-64yrs
- 35% men aged 65-74yrs
- > 50% men aged over 75yrs
- rates for women are approximately half that of men up to age 74yrs, then they increase to about 35% for women over 75yrs
it is exacerbated by drug induced ototoxicity and noise-induced deafness

multifactorial in aetiology;
it is thought to result from age-related degeneration of the cochlea with the cumulative effects of extrinsic damage (exposure to noise and other ototoxic agents) and intrinsic disorders (e.g. medical disorders), as well as inter-individual differences in genetic susceptibility.

presbycusis is a prevalent form of age-related hearing loss that also hinders speech recognition.
there appears to be a a specific neurobiological link between hearing loss and cognitive decline called the Functional-Structural Ratio (FSR) - the putamen and fusiform gyrus (involved in processing sound and speech) and the precuneus and medial superior frontal gyrus (involved in memory and decision-making) become less connected to functional brain networks in those with presbycusis¹⁾

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