Department of Hearing and Speech Sciences, University of Maryland, College Park, Maryland, United States.
Trends Hear. 2020 Jan-Dec;24:2331216520956560. doi: 10.1177/2331216520956560.
Accurate processing of temporal information is critical to understanding speech through a cochlear implant (CI). This has potential implications for the growing population of CI users who are ≥65 years of age because of age-related auditory temporal processing deficits. The goal of this study was to measure temporal processing ability in a gap detection task in younger, middle-aged, and older CI users and to determine the relative contributions of chronological age and peripheral neural survival to performance. Single-electrode gap detection thresholds (GDTs) were measured using direct stimulation at five electrode locations and three electrical stimulation rates. The relationship between peripheral status (e.g., electrode-to-neural interface) and GDTs was assessed by the slope of the electrically evoked compound action potential (ECAP) amplitude growth function. Results showed that ECAP slope was the strongest subject-level predictor of GDTs. Steeper ECAP slopes, which are partially indicative of better peripheral function, were associated with better GDTs in younger participants. However, ECAP slope significantly interacted with stimulation rate and age, suggesting that ECAP slopes were not predictive of GDTs in middle-aged and older participants at some stimulation rates. ECAP slope was also related to age, with middle-aged and older participants exhibiting relatively shallow slopes and smaller ranges of slopes compared with younger participants. This pattern of ECAP results limited the evaluation of the independent effects of aging per se and peripheral status on temporal processing ability.
准确处理时间信息对于通过人工耳蜗（CI）理解言语至关重要。对于年龄在 65 岁及以上的越来越多的 CI 用户来说，这具有潜在的影响，因为他们存在与年龄相关的听觉时间处理缺陷。本研究的目的是测量年轻、中年和老年 CI 用户在间隙检测任务中的时间处理能力，并确定年龄和周围神经存活对表现的相对贡献。使用直接刺激在五个电极位置和三个电刺激率下测量单电极间隙检测阈值（GDT）。通过评估电诱发复合动作电位（ECAP）幅度增长函数的斜率来评估外围状态（例如，电极-神经界面）与 GDT 之间的关系。结果表明，ECAP 斜率是 GDT 的最强受试者水平预测指标。斜率较陡，表明周围功能较好，与年轻参与者的 GDT 较好相关。然而，ECAP 斜率与刺激率和年龄显著相互作用，表明在某些刺激率下，ECAP 斜率不能预测中年和老年参与者的 GDT。ECAP 斜率也与年龄有关，与年轻参与者相比，中年和老年参与者的斜率相对较浅，斜率范围较小。这种 ECAP 结果模式限制了对衰老本身和周围状态对时间处理能力的独立影响的评估。
