Supplementary Material for: Binaural Perception in Single-Sided Deaf Cochlear Implant Users with Unrestricted or Restricted Acoustic Hearing in the Non-Implanted Ear

Cochlear implantation (CI) can benefit patients with single-sided deafness (SSD) in terms of sound localization, speech understanding in noise, tinnitus severity, and quality of life (QoL). In previous studies, CI outcomes have been largely reported for SSD patients with normal “unrestricted” hearing in the contralateral ear. However, SSD patients may often have some degree of hearing loss in the contralateral ear (“restricted” acoustic hearing). In this study, we report results from a French clinical trial for CI in in SSD patients (NCT02204618). Localization, speech reception thresholds (SRTs) in noise, tinnitus severity, and QoL were evaluated in 18 SSD patients 1 year after CI. Data were analyzed for 2 subject groups according to the pure-tone average thresholds in the non-implanted ear: unrestricted acoustic hearing (UNRES; ≤25 dB HL; n = 10) and restricted acoustic hearing (RES; > 25 dB HL; n = 8). Across all subjects, localization was significantly better with the CI on than off (p = 0.005); there was no significant difference between subject groups (p = 0.301). When speech and noise were co-located (S0N0), there was no significant difference in SRTs with the CI on or off (p = 0.480); SRTs were significantly better for the UNRES than for the RES group (p = 0.005). When speech and noise were spatially separated (SCINNH), SRTs were significantly better with the CI on than off (p < 0.001). While SRTs were better for the UNRES than for the RES group (p = 0.024), the CI benefit was more than 50% greater for the RES group due to the restoration of high-frequency speech cues. Questionnaire data showed that tinnitus severity was significantly reduced (p = 0.045) and QoL was significantly improved after one year of experience with the CI (p < 0.001). Age at testing was significantly correlated with SRTs for the S0N0 condition; duration of deafness was correlated with SRTs for the SCINNH condition. There were relatively few correlations between behavioral and subjective measures, suggesting that both were valuable when assessing CI benefits for SSD patients. The present data suggest that indications for CI should be expanded to include unilaterally deaf patients who have normal hearing or mild-to-moderate hearing loss in the non-implanted ear.

人工耳蜗植入（Cochlear Implantation, CI）可在声源定位、噪声下言语识别、耳鸣严重程度及生活质量（Quality of Life, QoL）等维度使单侧听力损失（Single-Sided Deafness, SSD）患者获益。既往相关研究中，人工耳蜗植入预后的报道多聚焦于对侧耳听力正常（即‘无限制’听觉）的单侧听力损失患者。然而，多数单侧听力损失患者的对侧耳常存在不同程度的听力损失，即‘受限’听觉功能。本研究报告了一项针对单侧听力损失患者的法国临床试验（NCT02204618）的结果。本研究纳入18名单侧听力损失患者，在人工耳蜗植入1年后对其声源定位能力、噪声下言语接受阈（Speech Reception Thresholds, SRTs）、耳鸣严重程度及生活质量进行评估。研究根据非植入耳的纯音听阈均值将受试者分为两组：无限制听觉组（UNRES：纯音听阈均值≤25 dB HL，n=10）与受限听觉组（RES：纯音听阈均值>25 dB HL，n=8）。全组受试者佩戴人工耳蜗时的声源定位能力显著优于未佩戴时（p=0.005），但两组受试者间的定位能力无显著差异（p=0.301）。当言语与噪声源位置一致（S0N0）时，佩戴与未佩戴人工耳蜗的言语接受阈无显著差异（p=0.480），且无限制听觉组的言语接受阈显著优于受限听觉组（p=0.005）。当言语与噪声源空间分离（SCINNH）时，佩戴人工耳蜗的言语接受阈显著优于未佩戴时（p<0.001）；尽管无限制听觉组的言语接受阈仍优于受限听觉组（p=0.024），但由于高频言语线索的恢复，受限听觉组的人工耳蜗获益幅度超过50%。问卷调研数据显示，佩戴人工耳蜗1年后，受试者的耳鸣严重程度显著降低（p=0.045），生活质量显著改善（p<0.001）。检测时的年龄与S0N0条件下的言语接受阈显著相关；耳聋病程与SCINNH条件下的言语接受阈存在相关性。行为学指标与主观评价指标间的相关性相对较少，提示二者在评估单侧听力损失患者的人工耳蜗获益时均具有重要应用价值。本研究数据表明，人工耳蜗植入的适应证应拓展至非植入耳听力正常或存在轻中度听力损失的单侧耳聋患者。