[Effects of moderate noises on early auditory evoked potentials in man, in relation to age].

Thirty men and thirty women, the first half of them 40-50 years old, and the other half 15-20 years old, were exposed successively for 15 min to four different noises at the same continuous equivalent level LAeq = 75 dB. Auditory brainstem evoked potentials were recorded before and after exposure to each noise. No difference was found between these noises as to their effects upon evoked potentials. After exposure to noise, a significant lengthening of L1, L3 and L5 latencies was observed in men. No significant lengthening was observed in women, although a lengthening of latencies was present in a majority of them. The three latencies, L3 and L5 latencies in particular, were found significantly longer in men than in women. L1 and L5 latencies were significantly more lengthened by noise in men than in women. In both sexes, L5 latencies were found significantly longer in older subjects; the same was true of L3 latencies in male subjects. Noise did not significantly modify intervals between peaks. I-V interval was found significantly longer in older male and female subjects; the same was true of I-III intervals in men.