Peters Jeroen P M, Bennink Edwin, van Zanten Gijsbert A
Department of Otorhinolaryngology and Head and Neck Surgery, University Medical Center Utrecht, Utrecht, The Netherlands,
UMC Utrecht Brain Center, Utrecht, The Netherlands,
Audiol Neurootol. 2019;24(1):38-48. doi: 10.1159/000499154. Epub 2019 Apr 17.
In electric-acoustic pitch matching experiments in patients with single-sided deafness and a cochlear implant, the observed "mismatch" between perceived pitch and predicted pitch, based on the amended Greenwood frequency map, ranges from -1 to -2 octaves. It is unknown if and how this mismatch differs for perimodiolar versus lateral wall electrode arrays.
We aimed to investigate if the type of electrode array design is of influence on the electric-acoustic pitch match.
Fourteen patients (n = 8 with CI422 + lateral wall electrode array, n = 6 with CI512 + perimodiolar electrode array; Cochlear Ltd.) compared the pitch of acoustic stimuli to the pitch of electric stimuli at two test sessions (average interval 4.3 months). We plotted these "pitch matches" per electrode contact against insertion angle, calculated from high-resolution computed tomography scans. The difference between these pitch matches and two references (the spiral ganglion map and the default frequency allocation by Cochlear Ltd.) was defined as "mismatch."
We found average mismatches of -2.2 octaves for the CI422 group and -1.3 octaves for the CI512 group. For any given electrode contact, the mismatch was smaller for the CI512 electrode array than for the CI422 electrode array. For all electrode contacts together, there was a significant difference between the mismatches of the two groups (p < 0.05). Results remained stable over time, with no significant difference between the two test sessions considering all electrode contacts. Neither group showed a significant correlation between the mismatch and phoneme recognition scores.
The pitch mismatch was smaller for the perimodiolar electrode array than for the lateral wall electrode array.
在单侧耳聋且植入人工耳蜗患者的电声音调匹配实验中，基于修正的格林伍德频率图，观察到的感知音调与预测音调之间的“不匹配”范围为 -1 至 -2 个八度。尚不清楚这种不匹配在蜗周电极阵列与侧壁电极阵列之间是否存在差异以及如何存在差异。
我们旨在研究电极阵列设计类型是否会影响电声音调匹配。
14 名患者（8 名使用 CI422 + 侧壁电极阵列，6 名使用 CI512 + 蜗周电极阵列；科利耳有限公司）在两个测试阶段（平均间隔 4.3 个月）将声刺激的音调与电刺激的音调进行比较。我们根据高分辨率计算机断层扫描计算出的插入角度，针对每个电极触点绘制这些“音调匹配”情况。这些音调匹配与两个参考标准（螺旋神经节图和科利耳有限公司的默认频率分配）之间的差异被定义为“不匹配”。
我们发现 CI422 组的平均不匹配为 -2.2 个八度，CI512 组为 -1.3 个八度。对于任何给定的电极触点，CI512 电极阵列的不匹配小于 CI 422 电极阵列。对于所有电极触点而言，两组的不匹配之间存在显著差异（p < 0.05）。随着时间推移结果保持稳定，考虑所有电极触点时两个测试阶段之间无显著差异。两组均未显示不匹配与音素识别分数之间存在显著相关性。
蜗周电极阵列的音调不匹配小于侧壁电极阵列。
