Black R C, Clark G M, O'Leary S J, Walters C
Acta Otolaryngol Suppl. 1983;399:5-17. doi: 10.3109/00016488309105588.
Brainstem response audiometry for intracochlear electrical stimulation of normal-hearing and deafened cats was investigated. In normal cochleas the brainstem response amplitude grew slowly near threshold as a current-amplitude dependent process, identified as electrophonic in origin. This terminated in a rapidly growing charge-dependent process at approximately 20 dB above threshold, identified as direct electrical stimulation of the auditory nerve. Small levels of white noise (25-35 dB SPL) were sufficient to mask most of the electrophonic response, leaving the direct stimulation process essentially unmodified. In cochleas damaged with d.c. currents and loud sounds, only a rapidly growing charge-dependent process was observed which grew similarly to that in normal-hearing cats but occurred at lower currents. This indicates that possibly the electrical properties of the cochlea were altered in the deafening process, suggesting the inadequacy of normal animals as deaf models for electrical stimulation. Using the technique of derived brainstem responses, it was shown that direct electrical stimulus components were localized to the vicinity of the stimulus electrode with electrophonic components distributed more widely. However, at high currents there was some evidence of the stimulus spreading into the internal auditory meatus.
研究了对听力正常和致聋猫进行耳蜗内电刺激时的脑干反应测听法。在正常耳蜗中，脑干反应幅度在阈值附近缓慢增长，这是一个与电流幅度相关的过程，其起源被确定为电声性的。这一过程在阈值以上约20分贝处终止于一个快速增长的与电荷相关的过程，该过程被确定为听神经的直接电刺激。小强度的白噪声（25 - 35分贝声压级）足以掩盖大部分电声反应，而直接刺激过程基本未受影响。在用直流电和强声致聋的耳蜗中，仅观察到一个快速增长的与电荷相关的过程，其增长方式与听力正常的猫相似，但发生在较低电流下。这表明在致聋过程中耳蜗的电学特性可能发生了改变，这意味着正常动物作为电刺激致聋模型可能并不合适。利用导出脑干反应技术表明，直接电刺激成分定位于刺激电极附近，而电声成分分布更广泛。然而，在高电流时，有证据表明刺激扩散到了内耳道。
