Department of Otolaryngology-Head and Neck Surgery, School of Medicine, University of California, San Francisco.
Department of Radiology and Biomedical Imaging, School of Medicine, University of California, San Francisco.
JAMA Otolaryngol Head Neck Surg. 2019 Feb 1;145(2):109-116. doi: 10.1001/jamaoto.2018.3096.
Cochlear implant users generally display poor pitch perception. Flat-panel computed tomography (FPCT) has recently emerged as a modality capable of localizing individual electrode contacts within the cochlea in vivo. Significant place-pitch mismatch between the clinical implant processing settings given to patients and the theoretical maps based on FPCT imaging has previously been noted.
To assess whether place-pitch mismatch is associated with poor cochlear implant-mediated pitch perception through evaluation of an individualized, image-guided approach toward cochlear implant programming on speech and music perception among cochlear implant users.
DESIGN, SETTING, AND PARTICIPANTS: A prospective cohort study of 17 cochlear implant users with MED-EL electrode arrays was performed at a tertiary referral center. The study was conducted from June 2016 to July 2017.
Theoretical place-pitch maps using FPCT secondary reconstructions and 3-dimensional curved planar re-formation software were developed. The clinical map settings (eg, strategy, rate, volume, frequency band range) were modified to keep factors constant between the 2 maps and minimize confounding. The acclimation period to the maps was 30 minutes.
Participants performed speech perception tasks (eg, consonant-nucleus-consonant, Bamford-Kowal-Bench Speech-in-Noise, vowel identification) and a pitch-scaling task while using the image-guided place-pitch map (intervention) and the modified clinical map (control). Performance scores between the 2 interventions were measured.
Of the 17 participants, 10 (58.8%) were women; mean (SD) was 59 (11.3) years. A significant median increase in pitch scaling accuracy was noted when using the experimental map compared with the control map (4 more correct answers; 95% CI, 0-8). Specifically, the number of pitch-scaling reversals for notes spaced at 1.65 semitones or greater decreased when an image-based approach to cochlear implant programming was used vs the modified clinical map (4 mistakes; 95% CI, 0.5-7). Although there was no observable median improvement in speech perception during use of an image-based map, the acute changes in frequency allocation and electrode channel deactivations used with the image-guided maps did not worsen consonant-nucleus-consonant (-1% correct phonemes, 95% CI, -2.5% to 6%) and Bamford-Kowal-Bench Speech-in-Noise (0.5-dB difference; 95% CI, -0.75 to 2.25 dB) median performance results relative to the clinical maps used by the patients.
An image-based approach toward ochlear implant mapping may improve pitch perception outcomes by reducing place-pitch mismatch. Studies using a longer acclimation period with chronic stimulation over months may help assess the full range of the benefits associated with personalized image-guided cochlear implant mapping.
人工耳蜗使用者通常表现出较差的音高感知能力。平板计算机断层扫描（FPCT）最近已成为一种能够在体内定位耳蜗内单个电极接触的方式。先前已经注意到，临床植入物处理设置与基于 FPCT 成像的理论图谱之间存在显著的音位-音高不匹配。
通过评估个体化、基于图像的人工耳蜗编程方法，评估人工耳蜗植入患者的语音和音乐感知中的音位-音高不匹配与人工耳蜗介导的音高感知差之间的关系。
设计、地点和参与者：在一家三级转诊中心进行了一项前瞻性队列研究，共纳入 17 名使用 MED-EL 电极阵列的人工耳蜗使用者。该研究于 2016 年 6 月至 2017 年 7 月进行。
使用 FPCT 二次重建和三维曲面平面重形成软件开发了理论音位-音高图谱。修改了临床图谱设置（例如，策略、速率、音量、频带范围），以使两个图谱之间的因素保持不变，并尽量减少混杂因素。对图谱的适应期为 30 分钟。
参与者在使用图像引导的音位-音高图谱（干预组）和修改后的临床图谱（对照组）时，完成语音感知任务（如辅音-核-辅音、巴姆福德-科瓦尔-本奇语音在噪声中的识别）和音高标度任务。测量了两种干预措施之间的性能得分。
17 名参与者中，有 10 名（58.8%）为女性；平均（标准差）年龄为 59（11.3）岁。与对照组相比，使用实验图谱时，音高标度准确性的中位数显著增加（多答对 4 个；95%CI，0-8）。具体来说，当使用基于图像的人工耳蜗编程方法时，1.65 半音或更大间距的音高标度反转次数减少（4 个错误；95%CI，0.5-7）。尽管在使用基于图像的图谱时，语音感知没有观察到中位数改善，但与患者使用的临床图谱相比，急性改变频率分配和电极通道停用并未使辅音-核-辅音（1%正确的音位，95%CI，-2.5%至 6%）和巴姆福德-科瓦尔-本奇语音在噪声中的识别（0.5dB 差异；95%CI，-0.75 至 2.25dB）的中位数性能结果变差。
基于图像的人工耳蜗图谱方法可以通过减少音位-音高不匹配来改善音高感知结果。使用更长的适应期和数月的慢性刺激的研究可能有助于评估与个性化图像引导人工耳蜗图谱相关的全部获益。
