ヒトの聴神経活動電位

聴器機能検査法研究 第71報

抄録

Auditory nerve action potentials in man to click stimuli could be obtained easily and nonsurgically from the external auditory meatus by means of an average response computer. The configurations of the responses are quite similar to those of the surgical approach reported by Ruben et al, Bordley et al, and Ronis. The present findings of the latency, the input-output relation, and the recovery function of the AP in man, at least in part, seem to fit in better with the studies on those of animal experiments by Derbyshire and Davis, Davis, Rosenblith, and others.
The significance of this nonsurgical recording is that a new field of objective audiometry will be opened by the neurophysiological responses of the ear. The present study of normal subjects has shown the followings:
1) A typical tracing of the response to clicks of moderate strength is a negative wave, “N1”, followed by a smaller second negative wave, “N2” and then occasionally a third still smaller negative wave, “N3”.
2) The latency of N1 is a function of the click intensity.
3) The input-output function of N1 shows two fairly distinct slopes of the growth, a small one with low threshold and a larger one with higher threshold.
4) The AP to clicks is masked by simultaneous stimulation of a white noise.
5) The recovery function of N1 shows an asymptotic approach to the full recovery.
Further works on the AP in man is necessary to evaluate the degree of impairment hearing in adults and children from the observations on the presence or the absence of the response, and to obtains diagnostic information on sensory-neural defects or subtractive loss.