Cochlear implants and listening effort: the interaction of cognitive and sensory constraints

项目摘要 老年人是美国人口中增长最快的部分，听力损失是第三大流行病 慢性疾病未经治疗的听力损失会影响有效的沟通，生活质量， 并有可能加速认知能力的下降。人工耳蜗（CI）越来越多地用于老年人， 其中一个植入中心报告说，在最近十年期间， 年龄在60岁或以上的人接受CI。由CI提供的听觉输入随着 与听力正常或轻度至中度听力损失的人相比， 至少当通过单词识别的标准临床测试测量时（例如，CNC字）或 简单句子的感知（例如，AzBio句子）。然而，临床医生经常被患者所困惑， 特别是老年人，他们在标准测试中表现良好，但在日常语言中有很大的困难 交互. 该授权建立在如下假设的基础上： 一个CI和有限的认知资源可能会导致一个“临界点”，当听众面临复杂的 句子和话语以正常的快速语速到达。超过这个临界点，沟通可能 即使对于标准语音清晰度分数高于平均值的CI接受者，也变得太困难。这 格兰特汇集了三种融合方法的独特组合：（1）我们研究了 年轻人和老年人CI用户理解和记住语言复杂的内容 句子和多句语篇，并探讨对听者认知机制的潜在影响 用于处理语音输入，这是CI研究中尚未探讨的潜在问题;（2）对于每个实验，我们 将进行一项平行研究，正常听力的年轻人和老年人使用通道声码， 未经处理的语音，前者允许系统地确定信号之间的相互作用， 退化和复杂性的语音材料对他们的回忆，后者来说明基线 年龄匹配的成年人在相同任务上的最佳表现;（3）我们将使用现代瞳孔测量法 作为时间锁定到语音输入的内容的认知努力的客观指标来测量。的 所获得的知识将检验当前的资源分配模式和倾听努力， 当年轻和年长的成年CI用户面对日常生活的自然复杂性时， 句子和话语。本研究结果将可作为临床心理辅导之参考 并将有助于为老年人开发更全面的评估电池和康复策略 线人

PROJECT SUMMARY Older adults are the fastest growing segment of the U.S. population, with hearing loss the third most prevalent chronic medical condition. Untreated, hearing loss can interfere with effective communication, quality of life, and potentially accelerate cognitive decline. Cochlear implants (CI) have seen increasing use for older adults, with one implant center reporting a nearly 500% increase over a recent ten-year period in the number of individuals aged 60 or older receiving CIs. The auditory input provided by a CI is sharply degraded with respect to that of a person with normal hearing or even with mild to moderate hearing loss, but patients can adapt well to this novel input- at least when measured by standard clinical tests of word identification (e.g., CNC words) or perception of simple sentences (e.g., AzBio sentences). However, clinicians are often puzzled by patients, especially older adults, who seem to do well on standard tests but report major difficulties in everyday speech interactions. This grant builds upon the hypothesis that the combined constraints of the sharply degraded signal provided by a CI and finite cognitive resources may lead to a “tipping point” when listeners are confronted with complex sentences and discourse arriving at normally rapid speech rates. Beyond this tipping point communication may become too difficult, even for CI recipients whose standard speech intelligibility scores are above average. This grant brings together a unique combination of three converging approaches: (1) We examine the ability of younger adult and older adult CI users to comprehend and remember the content of linguistically complex sentences and multi-sentence discourse, and probe potential effects on the cognitive mechanisms listeners use to process speech input, an underlying issue as yet unexplored in CI research; (2) For each experiment we will conduct a parallel study with normal-hearing younger and older adults using channel vocoded and unprocessed speech, with the former allowing a systematic determination of the interaction between signal degradation and the complexity of the speech materials on their recall, and the latter to illustrate a baseline of optimal performance on the same tasks for age-matched adults; (3) We will use modern pupillometry measures as an objective index of cognitive effort time-locked to the content of the speech input. The knowledge gained will test current models of resource allocation and listening effort as mechanisms underlying effects of cognitive load when younger and older adult CI users face the natural complexity of everyday sentences and discourse. Results of the studies will be valuable for counseling CI recipients and their families and will help develop more comprehensive evaluation batteries and rehabilitative strategies for the older adult CI recipient.