[Effect of aging on distortion product otoacoustic emissions]

The effect of aging on distortion product otoacoustic emissions (DPOAE) was investigated in 58 ears of 32 volunteers with normal hearing DPOAE levels to tones with a fixed frequency ratio (f2/f1 = 1.2) were measured with the CUBDIS system (MIMOSA Acoustics, USA). Age dependency of DPOAE level was clearly observed both in frequency plots (DP-gram) and input-output functions. In elderly persons, DPOAE levels for higher frequency primaries were significantly lower than in younger persons, when no remarkable change of audiometry threshold was noted. These results imply that the DPOAE level can be a sensitive indicator for age-related cochlear dysfunction.