Blamey P J, Dooley G J, Parisi E S, Clark G M
Department of Otolaryngology, University of Melbourne, East Melbourne, Victoria, Australia.
Hear Res. 1996 Sep 15;99(1-2):139-50. doi: 10.1016/s0378-5955(96)00095-0.
Cochlear implant users with some residual hearing in the non-implanted ear compared the pitch sensations produced by acoustic pure tones and pulsatile electric stimuli. Pitch comparisons were obtained for pure tones and electrical stimuli presented at different positions (electrodes) in the scala tympani, keeping the electric pulse rate fixed at 100, 250, or 800 pps. Similarly, pitch comparisons were obtained for electrical stimuli with variable pulse rates presented to two fixed electrode positions (apical and basal) in the cochlea. Both electrode position and pulse rate influenced the perceived pitch of the electrical signal and 'matched' electric and acoustic signals were found over a wide range of frequencies. There was a large variation between listeners. For some stimuli, listeners had difficulty in deciding whether the acoustic or electric stimulus was higher in pitch. Despite the variability, consistent trends were obtained from the data: higher frequencies tended to be matched by more basal electrodes for all pulse rates. Higher frequencies tended to be matched by higher pulse rates for both electrode positions. The electrode positions that 'matched' pure tones were more basal than predicted from the characteristic frequency coordinates of the basilar membrane in a normal human cochlea.
在未植入耳蜗的耳朵中仍有一些残余听力的人工耳蜗使用者，比较了纯音和脉动电刺激产生的音高感觉。在鼓阶的不同位置（电极）呈现纯音和电刺激时进行音高比较，同时将电脉冲率固定在100、250或800次/秒。同样，对于以可变脉冲率呈现给耳蜗中两个固定电极位置（顶部和基部）的电刺激，也进行了音高比较。电极位置和脉冲率都影响电信号的感知音高，并且在很宽的频率范围内都发现了“匹配”的电信号和声学信号。不同听众之间存在很大差异。对于某些刺激，听众难以确定声学刺激还是电刺激的音高更高。尽管存在变异性，但从数据中仍获得了一致的趋势：对于所有脉冲率，较高频率往往由更靠近基部的电极匹配。对于两个电极位置，较高频率往往由较高脉冲率匹配。“匹配”纯音的电极位置比正常人类耳蜗中基底膜的特征频率坐标所预测的更靠近基部。
