This study investigated the number of channels available to cochlear implant (CI) recipients for maximum speech understanding and sound quality for lateral wall electrode arrays—which result in large electrode-to-modiolus distances—featuring the greatest inter-electrode distances (2.1–2.4 mm), the longest active lengths (23.1–26.4 mm), and the fewest number of electrodes commercially available. Participants included ten post-lingually deafened adult CI recipients with MED-EL electrode arrays (FLEX28 and STANDARD) entirely within scala tympani. Electrode placement and scalar location were determined using computerized tomography. The number of channels was varied from 4 to 12 with equal spatial distribution across the array. A continuous interleaved sampling-based strategy was used. Speech recognition, sound quality ratings, and a closed-set vowel recognition task were measured acutely for each electrode condition. Participants did not demonstrate statistically significant differences beyond eight channels at the group level for almost all measures. However, several listeners showed considerable improvements from 8 to 12 channels for speech and sound quality measures. These results suggest that channel interaction caused by the greater electrode-to-modiolus distances of straight electrode arrays could be partially compensated for by a large inter-electrode distance or spacing.

中文翻译：

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语音识别作为具有大电极间距离的阵列的通道数的函数

本研究调查了人工耳蜗 (CI) 接受者可使用的通道数量，以实现侧壁电极阵列的最大语音理解和声音质量，从而导致较大的电极到蜗轴距离，具有最大的电极间距离 (2.1–2.4) mm）、最长的有效长度（23.1-26.4 mm）以及市售电极数量最少。参与者包括 10 名语后耳聋成年 CI 接受者，他们的 MED-EL 电极阵列（FLEX28 和 STANDARD）完全位于鼓阶内。使用计算机断层扫描确定电极放置和标量位置。通道数量从 4 到 12 不等，在整个阵列中空间分布均匀。使用基于连续交错采样的策略。针对每种电极条件对语音识别、声音质量评级和闭集元音识别任务进行了精确测量。对于几乎所有测量，参与者在组级别上没有表现出超过八个通道的统计显着差异。然而，一些听众的语音和声音质量测量结果显示，从 8 通道到 12 通道有了相当大的改进。这些结果表明，由直电极阵列的较大电极到轴轴距离引起的通道相互作用可以通过较大的电极间距离或间距来部分补偿。