Cortical Audiometry in Normal Hearing Subjects

Abstract

Our present investigation deals with the influence of three stimulus parameters an slow evoked potentials derived from the intact scalp after acoustic stimulation (sine tones of 60 σ duration) in normal hearing subjects. Random application of the stimulus (50 times, every 1 to 3”) is more efficient than a periodical stimulation (60 times, one stimulus every second). When stimulus intensity increases, the intensity of the reaction—mainly N₁-P₂—also increases, and the latency—mainly N₁ and P₂—decreases, provided that the 40 dB stimulation intensity is not exceeded. The lower frequencies (250, 500, 1000, and 2000 c/s) give rise to a much clearer cortical reaction than the higher frequencies (4000 and 8000 c/s).