Pfingst B E, Zwolan T A, Holloway L A
Kresge Hearing Research Institute, Department of Otolaryngology, University of Michigan Medical Center, Ann Arbor 48109-0506, USA.
Hear Res. 1997 Oct;112(1-2):247-60. doi: 10.1016/s0378-5955(97)00122-6.
Effects of electrode configuration and pulse duration on operating levels and on speech recognition performance were studied in a group of 14 adult postlingually deaf human subjects with Nucleus cochlear implants. The operating levels (based on detection threshold and maximum comfortable loudness levels) for narrowly spaced bipolar (BP) stimulation were found to be about 11 dB higher on average than those for widely spaced bipolar (BP+6) or monopolar (MP1) stimulation. Operating levels for common ground (CG) stimulation fell between those for BP and BP+6; the difference between BP and CG detection thresholds depended on pulse duration. Variation in detection thresholds and maximum comfortable loudness levels across the electrode array (electrodes 1-15) was larger for BP and CG stimulation than for BP+6 or MP1 stimulation, suggesting narrower spread of activation for the BP and CG configurations despite the higher current levels. Speech recognition performance was tested using experimental processor configurations. Among the experimental electrode configurations tested (BP, CG, and BP+6), the highest speech recognition scores were obtained with the BP+6 configuration in many subjects. Effects of pulse duration on speech recognition were less consistent and usually smaller than the effects of electrode configuration. The results indicate that electrode configuration is an important variable determining speech recognition performance and suggest that restriction of the size of neural population activated by individual channels of the prosthesis is not necessarily advantageous.
在一组14名成年语后聋的人工耳蜗植入者中，研究了电极配置和脉冲持续时间对工作水平及言语识别性能的影响。结果发现，窄间距双极（BP）刺激的工作水平（基于检测阈值和最大舒适响度水平）平均比宽间距双极（BP+6）或单极（MP1）刺激的工作水平高约11 dB。共地（CG）刺激的工作水平介于BP和BP+6之间；BP和CG检测阈值之间的差异取决于脉冲持续时间。与BP+6或MP1刺激相比，BP和CG刺激时整个电极阵列（电极1-15）上检测阈值和最大舒适响度水平的变化更大，这表明尽管电流水平较高，但BP和CG配置的激活扩散范围更窄。使用实验性处理器配置对言语识别性能进行了测试。在测试的实验电极配置（BP、CG和BP+6）中，许多受试者使用BP+6配置获得了最高的言语识别分数。脉冲持续时间对言语识别的影响不太一致，且通常小于电极配置的影响。结果表明，电极配置是决定言语识别性能的一个重要变量，并表明限制假体单个通道激活的神经群体大小不一定有利。
