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

项目总结 老年人是美国人口中增长最快的部分，听力损失排在第三位 慢性疾病。如果不治疗，听力损失会干扰有效的沟通，生活质量， 并有可能加速认知能力的下降。人工耳蜗(CI)在老年人中的使用越来越多， 一家植入中心报告说，在最近十年中，植入的数量增加了近500% 60岁或以上接受身份证明的个人。由CI提供的听觉输入随着尊重而急剧退化 对于听力正常的人，甚至是轻度到中度听力损失的人，但患者可以很好地适应 对于这种新的输入--至少当通过单词识别的标准临床测试(例如，Cnc单词)或 对简单句子的感知(例如，AzBio句子)。然而，临床医生往往对患者感到困惑， 尤其是老年人，他们似乎在标准测试中表现很好，但在日常言语中报告了很大的困难 互动。 这一授权建立在这样的假设之上，即由以下提供的急剧退化信号的组合约束 CI和有限的认知资源可能会导致听者在面对复杂语言时出现一个“临界点” 达到正常语速的句子和话语。超过这一临界点，沟通可能会 变得太难了，即使对于标准语音清晰度得分高于平均水平的CI接受者也是如此。这 格兰特将三种融合方法的独特组合结合在一起：(1)我们考察了 年轻人和老年人CI用户理解和记住复杂语言的内容 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研究中尚未探索的基本问题；(2)对于每个实验，我们 将对听力正常的年轻人和老年人进行一项平行研究，使用通道声码和 未处理的语音，前者允许系统地确定信号之间的相互作用 退化和语音材料的复杂性对他们的回忆，后者说明了基线 年龄匹配的成年人在相同任务中的最佳表现；(3)我们将使用现代瞳孔测量法 测量作为认知努力的客观指标，与言语输入的内容具有时效性。这个 所获得的知识将测试当前的资源分配和倾听努力模型，作为潜在的机制 青年和老年CI用户面对日常生活的自然复杂性时认知负荷的影响 句子和语篇。研究结果将对CI患者及其家人的咨询有价值 并将有助于为老年人开发更全面的评估单元和康复策略 CI收件人。

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.