Effect of speech distinctions and age differences on auditory event-related potentials.

P3 event-related potentials were recorded from 37 subjects in two age groups (19-25 and 61-75 years) listening to tones, stop + vowel (CV) monosyllables, and isolated vowels. P3 latencies were found to be significantly longer for older subjects in all stimulus conditions. CV latencies were also significantly longer than simple tone latencies with the increase being approximately 1.30 msec/year. Latencies to the vowel stimuli were somewhat more variable but also tended to be greater than the tone latencies. P3 amplitudes were greater for the tone stimuli than for the speech stimuli, but no significant age effects were found.