骨導ABRと気導ABRの潜時差に関する一考察
1988 年 31 巻 3 号 p. 137-144
詳細
1988 年 31 巻 3 号 p. 137-144
Bone-conducted ABRs and air-conducted ABRs with a vibrator on the forehead and the mastoid were obtained from 10 subjects with normal hearing. Click stimulation (one cycle of 2kHz, 3kHz, and 4kHz) was introduced through a bone vibrator and an earphone. The wave V latencies of recorded ABRs were compared respectively.
Wave V latency of bone-conducted ABR on the forehead was more prolonged than that the air-conducted ABR for stimulation of the same frequency. Also, the latency of bone-conducted ABR on the forehead proved to be longer than that on the mastoid. However, there was no latency difference between the air-conducted ABR and bone-conducted. ABR on the mastoid. Furthermore, the tendency of latency difference was independent from frequency of click stimulation.
We concluded that the prolongation of latency in the bone-conducted ABR on the forehead, comparing to the one in the air-conducted ABR, was mainly caused by conduction time from the forehead to the inner ear in the skull. In addition, another contributory factor was a poorer high frequency response of a bone vibrator than an ear-phone.
