Acoustically evoked potential: dependence upon age.

The slow components of the potentials evoked acoustically by pure tones (1 kHz, 0 to 90 dB HL) were compared between two groups of subjects. All subjects of one group were 22 years old; the members of the other group had an average age of 63 years. The P2-latencies of the older subjects were significantly shorter for 60, 75 and 90 dB HL than those of the younger group. This finding was interpreted as a sign of a decreased efferent inhibition of several nuclei of the auditory pathway in the older subjects. No significant difference between the two groups could be found for the amplitudes (N1/P2), the exponent of the intensity function, or the latencies of P1 and N1.