Department of Communication Sciences & Disorders, The University of Texas Rio Grande Valley, Edinburg, TX 78539, United States.
Department of Ear, Nose and Throat, GGS Medical College and Hospital, Baba Farid University of Health Sciences, Faridkot, Punjab 151203, India.
Hear Res. 2021 Jun;405:108245. doi: 10.1016/j.heares.2021.108245. Epub 2021 Apr 9.
Hearing with one ear is associated with auditory deprivation leading to cortical neuronal reorganization. Despite evidence for substantial effects of unilateral input on cortical and sub-cortical structures, the functional consequences of such alterations on human hearing is underexplored. Unilateral hearing impairment offers a unique model to study the perceptual consequences of cortical reorganization. The present study provides evidence for larger (poorer) difference limens for frequency for sounds heard by the normal ear of listeners with unilateral hearing loss relative to bilaterally normal-hearing controls. This difference in frequency discrimination ability was observed for the low (250 Hz), but not for the high-frequency tone (4000 Hz). Besides auditory perceptual effects, we also found reduced working memory capacity as revealed by forward and backward digit span measures. Contrary to the expectation, there was no significant association between frequency discrimination and working memory capacity in listeners with unilateral hearing loss. Auditory deprivation associated with unilateral hearing impairment affects low-frequency (pitch) discrimination and working memory capacity despite normal hearing in the intact ear. Such deficits in basic auditory processes and memory span for sounds heard by the normal ear may contribute to the hearing and communication difficulties experienced by listeners with unilateral or single-sided deafness.
单侧听力损失与听觉剥夺导致皮质神经元重组有关。尽管单侧输入对皮质和皮质下结构有实质性影响的证据确凿，但这种改变对人类听力的功能后果仍未得到充分探索。单侧听力障碍为研究皮质重组的知觉后果提供了一个独特的模型。本研究为单侧听力损失患者正常耳听到的声音的频率差异阈限（即更好/更差）大于双侧正常听力对照组提供了证据。这种频率辨别能力的差异在低频（250Hz）时观察到，但在高频（4000Hz）时没有观察到。除了听觉知觉效应，我们还发现工作记忆容量减小，表现为顺背和倒背数字广度测试。与预期相反，单侧听力损失患者的频率辨别力与工作记忆容量之间没有显著关联。单侧听力损失引起的听觉剥夺会影响低频（音高）辨别力和正常耳听到的声音的工作记忆容量，尽管未受损耳的听力正常。这种正常耳听到的声音的基本听觉过程和记忆跨度的缺陷可能导致单侧或单侧聋患者的听力和交流困难。
