Influence of age and presbyacusis on DPOAE.

The influence of presbyacusis on distortion-product otoacoustic emissions (DPOAEs) was studied on 180 ears of 96 normal-hearing subjects. The subjects' ages were distributed equally and ranged from 14 to 82 years. It was shown that there is a highly significant decrease in DPOAE amplitudes during the ageing process. By means of special statistical procedures, such as partial correlation and multiple regression, it was proved that the main reason for this is deterioration in pure-tone thresholds. However, other age-related effects were determined and were also found to lead to a further decrease in DPOAE amplitudes. The latter might be due to middle ear alterations in elderly people. Knowledge of the influence of presbyacusis on DPOAE is important if DPOAEs are to be used in expert assessment of inner ear disorders, for example, occupational noise-induced hearing loss.