EFFECTS OF ASYMMETRIC HEARING IN ACOUSTIC LISTENERS AND COCHLEAR IMPLANT USERS

描述（由申请人提供）：单耳听力严重降低信号分离和通信。许多患者的听力功能明显不对称。我们拟在三个患者群体中研究听力不对称的影响。在每个群体中，个体都有一只耳朵是聋的；然而，他们在听力“较好”的耳朵上有所不同，听力正常、中度听力损失或植入了人工耳蜗。在Aim 1中，我们检验了一个假设，即在单侧听力损失的成年人中，完整（正常）耳中的听觉加工被破坏。具体来说，我们预测单侧耳聋患者对频谱和时间调制声音的处理与正常听力对照单耳听力相比减少。在目的2中，我们使用成像方法验证了单侧耳聋导致处理频谱和时间声音的正常皮质不对称重组的假设。我们还将研究单侧耳聋对被剥夺的听觉皮层中选定的听觉区域与大脑其余部分之间相关活动的影响。在Aim 3a中，我们假设一只耳朵的残余听力减少了另一只耳朵耳聋的负面影响。成年患者有一只耳朵符合目前人工耳蜗的候选条件，一只耳朵有中度听力损失。较差的耳朵被植入。结果与双耳耳聋接受一次植入的个体进行了比较。在Aim 3b中，我们假设通过在一只耳朵植入人工耳蜗的电听力可以减少另一只耳朵耳聋的负面影响。对于接受顺序人工耳蜗植入的儿童和成人（在第一次植入后数月至数年植入一只耳朵），我们使用流动源语音识别、多源模拟真实噪声环境和听力障碍调查来确定顺序植入耳朵之间的关系。这些研究结果将为扩大儿童和成人单耳植入术标准和建立双耳植入术新标准提供急需的依据。此外，所提出的转化研究将促进对耳聋神经通路的可塑性和优势性的理解，并指导对听力不对称患者的干预，无论是由于声学不对称还是单侧人工耳蜗植入。单耳听力会导致在噪音环境下的语言理解能力低下，无法定位声音，并且一整天都要付出巨大的努力才能沟通。本研究将满足迫切的临床需求：1)了解单侧听力损失的后果；2)扩大单耳人工耳蜗植入的标准；3)建立儿童和成人双侧人工耳蜗植入的新标准。行为学和影像学研究结果将促进对不对称听力影响的理解，并指导患者的干预。

DESCRIPTION (provided by applicant): Listening with just one ear seriously degrades signal segregation and communication. Many patients function with noticeable asymmetry in hearing. We propose to study the effects of asymmetric hearing in three patient populations. In each group, individuals have one deaf ear; however, they differ in their "better" hearing ear, which has either normal hearing, moderate hearing loss, or hears with a cochlear implant. In Aim 1, we test the hypothesis that auditory processing in the intact (normal) ear is disrupted in adults with unilateral hearing loss. Specifically, we predict decreased processing of spectrally and temporally modulated sounds in individuals with unilateral deafness compared to normal hearing controls listening with one ear. In Aim 2, using imaging methods, we test the hypothesis that unilateral deafness leads to reorganization in the normal cortical asymmetry in processing spectral and temporal sounds. We will also examine the consequences of unilateral deafness on correlated activity between selected auditory regions in the deprived auditory cortex and the rest of the brain. In Aim 3a, we hypothesize that residual hearing in one ear reduces the negative effect of deafness in the opposite, untreated ear. Adult patients have one ear that meets current cochlear implant candidacy and one ear with moderate hearing loss. The poorer ear is implanted. Results are compared to individuals with deafness in both ears who receive one implant. In Aim 3b, we hypothesize that electric hearing through a cochlear implant in one ear reduces the negative effect of deafness in the opposite, untreated ear. For both children and adults who receive sequential cochlear implants (one ear implanted months to years after the first), we determine the relationship between sequentially implanted ears using roving-source speech recognition, multi-source simulation of real-world noise environments, and investigation of hearing handicap. The information obtained from these studies will provide an urgently needed basis for expanding criteria for implantation in one ear and establishing new criteria for implantation in both ears for children and adults. In addition, the proposed translational research will advance understanding of plasticity and dominance of the neural pathways in deafness and guide intervention for patients with asymmetric hearing, either due to acoustic asymmetry or unilateral cochlear implantation. Listening with just one ear results in poor speech understanding in noise, inability to localize sound and tremendous effort to communicate throughout the day. This research will meet urgent clinical needs to 1) understand the consequences of unilateral hearing loss, 2) expand criteria for cochlear implantation in one ear, and 3) establish new criteria for bilateral implantation in children and adults. Behavioral and imaging study results will advance understanding of the effects of asymmetric hearing and guide intervention for patients.