Presbycusis and noise-induced hearing loss.

In a longitudinal and an age cohort comparing study the influence of aging and occupational noise exposure on hearing sensitivity was studied. The participants of the longitudinal study were studied at 70, 75, and 79 years of age. Seventy year old men exposed to occupational noise had 10 to 15 dB poorer hearing in the high frequency range than nonexposed men. The difference in hearing acuity decreased with increasing age. The differences between exposed and nonexposed older persons was no longer significant at age 79. In women there were no differences in hearing sensitivity between those exposed to noise and those not exposed to noise. Men not exposed to noise had 10 to 15 dB poorer hearing at 4 kHz compared with women of the same age also not exposed to noise.