Boys Town National Research Hospital, Omaha, NE.
The Ohio State University, Columbus.
J Speech Lang Hear Res. 2021 Aug 9;64(8):3330-3342. doi: 10.1044/2021_JSLHR-20-00574. Epub 2021 Jul 12.
Purpose In individuals with cochlear implants, speech recognition is not associated with tests of working memory that primarily reflect storage, such as forward digit span. In contrast, our previous work found that vocoded speech recognition in individuals with normal hearing was correlated with performance on a forward digit span task. A possible explanation for this difference across groups is that variability in auditory resolution across individuals with cochlear implants could conceal the true relationship between speech and memory tasks. Here, our goal was to determine if performance on forward digit span and speech recognition tasks are correlated in individuals with cochlear implants after controlling for individual differences in auditory resolution. Method We measured sentence recognition ability in 20 individuals with cochlear implants with Perceptually Robust English Sentence Test Open-set sentences. Spectral and temporal modulation detection tasks were used to assess individual differences in auditory resolution, auditory forward digit span was used to assess working memory storage, and self-reported word familiarity was used to assess vocabulary. Results Individual differences in speech recognition were predicted by spectral and temporal resolution. A correlation was found between forward digit span and speech recognition, but this correlation was not significant after controlling for spectral and temporal resolution. No relationship was found between word familiarity and speech recognition. Forward digit span performance was not associated with individual differences in auditory resolution. Conclusions Our findings support the idea that sentence recognition in individuals with cochlear implants is primarily limited by individual differences in working memory processing, not storage. Studies examining the relationship between speech and memory should control for individual differences in auditory resolution.
目的 在植入人工耳蜗的个体中，语音识别与主要反映存储的工作记忆测试（如顺向数字广度测试）无关。相比之下，我们之前的研究发现，正常听力个体的语音编码识别与顺向数字广度任务的表现相关。对于两组之间的这种差异，一种可能的解释是，人工耳蜗植入个体的听觉分辨率变异性可能掩盖了语音和记忆任务之间的真实关系。在这里，我们的目标是在控制听觉分辨率个体差异后，确定人工耳蜗植入个体的顺向数字广度和语音识别任务的表现是否相关。
方法 我们使用感知稳健英语句子测试开放式句子测量了 20 名人工耳蜗植入个体的句子识别能力。使用光谱和时间调制检测任务评估听觉分辨率的个体差异，使用听觉顺向数字广度测试评估工作记忆存储，使用自我报告的单词熟悉度评估词汇量。
结果 语音识别的个体差异由光谱和时间分辨率预测。顺向数字广度和语音识别之间存在相关性，但在控制光谱和时间分辨率后，这种相关性并不显著。单词熟悉度与语音识别之间没有关系。顺向数字广度测试成绩与听觉分辨率的个体差异无关。
结论 我们的发现支持这样一种观点，即在植入人工耳蜗的个体中，句子识别主要受到工作记忆处理的个体差异的限制，而不是存储。研究语音和记忆之间关系的研究应该控制听觉分辨率的个体差异。
