Jerger J, Chmiel R, Allen J, Wilson A
Division of Audiology & Speech Pathology, Baylor College of Medicine, Houston, Texas.
Ear Hear. 1994 Aug;15(4):274-86. doi: 10.1097/00003446-199408000-00002.
There is converging evidence that aging causes a progressive decline in the central processing of speech and that this decline is greater for left-ear than for right-ear input. In the present paper we investigated, by means of a dichotic sentence identification paradigm, some parameters of the "left-ear effect." We analyzed the clinical records of 356 individuals, 203 males and 153 females, to whom the Dichotic Sentence Identification (DSI) Test had been administered as part of routine audiometric assessment. Subjects ranged in age from 9 to 91 yr. The DSI test was always carried out in two modes: free report (FR) and directed report (DR). In the FR mode the subject reported what was heard in both ears. In the DR mode the subject reported only what was heard in one precued ear. In half of the trials the right ear was precued, in the other half the left ear was precued. Findings confirm a progressively larger right-ear advantage, or left-ear deficit, with increasing age. We document this effect in both the FR and DR modes, then demonstrate that the effects cannot be attributed to interaural asymmetries in threshold sensitivity. Comparison of male and female data suggest a gender difference in the effect of age on the left-ear deficit. Males show a larger effect then females in both modes of test administration. Finally, we propose a model of dichotic listening performance that attempts to explain ear asymmetry as the linear combination of an auditory/structural component and a task-related/cognitive component. We then show how these hypothetical components change with age in the present sample.
越来越多的证据表明，衰老会导致言语中枢处理能力逐渐下降，而且左耳输入的这种下降比右耳更明显。在本文中，我们通过双耳分听句子识别范式研究了“左耳效应”的一些参数。我们分析了356名个体（203名男性和153名女性）的临床记录，这些个体均接受了双耳分听句子识别（DSI）测试，该测试是常规听力评估的一部分。受试者年龄在9岁至91岁之间。DSI测试总是以两种模式进行：自由报告（FR）和定向报告（DR）。在FR模式下，受试者报告双耳听到的内容。在DR模式下，受试者只报告在一个预先提示的耳朵中听到的内容。在一半的试验中，右耳被预先提示，在另一半试验中，左耳被预先提示。研究结果证实，随着年龄的增长，右耳优势或左耳缺陷会逐渐增大。我们在FR和DR模式中都记录了这种效应，然后证明这些效应不能归因于阈值敏感性的双耳不对称。对男性和女性数据的比较表明，年龄对左耳缺陷的影响存在性别差异。在两种测试模式下，男性的影响都比女性大。最后，我们提出了一个双耳分听表现模型，试图将耳不对称解释为听觉/结构成分和任务相关/认知成分的线性组合。然后，我们展示了在当前样本中这些假设成分如何随年龄变化。
