EFFECTS OF ASYMMETRIC HEARING IN ACOUSTIC LISTENERS AND COCHLEAR IMPLANT USERS

描述（由申请人提供）：我们研究的目标是了解成人和儿童的非对称性听力损失的影响。例如，当一只耳朵有严重的听力损失而另一只耳朵有正常的听力时，就会发生听力不对称。或者，当一只耳朵严重失聪，但较好的耳朵有部分听力。在这两种情况下，不平衡的输入会在心理上影响日常生活中的沟通，并产生其他负面后果。在目标1中，我们确定了导致单侧听力损失成人和儿童结局的变异性来源。了解这种变异性可以改善患者的咨询和治疗选择。我们将通过调查认知能力、相关的人口统计数据和性能指标来评估预测噪声和定位中语音识别的因素。在目标2中，我们评估了单侧听力损失患者在噪声中理解言语的缺陷影响非听觉认知脑区的加工的假设。我们提出了一个功能成像研究的活动引起的高和低的可预测性的句子在存在和不存在的多说话者牙牙学语。我们预测，在噪音中补偿退化的言语理解涉及更大的激活颞顶叶，下和背外侧额叶，扣带皮层的认知中心，在成人单侧听力损失相比，听力正常。在目标3中，我们研究了人工耳蜗植入对患有不对称听力损失的成人和儿童以及不同年龄的耳聋和听力病史的听力较差的耳朵的益处。我们预测，即使一只耳朵有部分听力，大脑已经学会了听到一个相当好的声音信号，在较贫穷的耳朵耳聋的发病年龄将与结果。在目标4中，我们确定了双侧人工耳蜗植入者中导致两耳之间语音识别不对称和双侧性能降低的因素。在语前聋儿童中，我们预计手术之间的时间越长，两耳之间的语音识别的不对称性越大，双侧表现也越差。在语后成人中，我们预测耳蜗之间电极放置的较大差异与两耳之间语音识别的较大不对称性、双侧性能降低以及音高感知的较大耳间差异相关。总之，拟议的研究计划将探讨单侧听力损失的行为变异和大脑重组的基础。研究结果将确定听力不对称如何影响行为结果，以及是否存在单侧耳聋早期发作的新考虑因素。所获得的知识可能会影响对患有不对称听力损失的儿童和成人治疗耳、治疗类型和治疗时机的决定。最后，研究结果将提高对耳蜗间电极放置效果的理解，并可能影响双侧植入接受者的治疗决策。

DESCRIPTION (provided by applicant): The goal of our research is to understand the effects of asymmetric hearing loss in adults and children. Hearing asymmetry occurs, for example, when one ear has profound hearing loss and the other ear has normal hearing. Or, when one ear is profoundly deaf but the better ear has partial hearing. In either case, the imbalanced inputs detrimentally affect communication in everyday life and have other negative consequences. In Aim 1, we identify the sources of variability contributing to outcomes observed in adults and children with unilateral hearing loss. Understanding this variability could improve counseling and treatment options for patients. We will evaluate factors that predict speech recognition in noise and localization by investigating cognitive abilities, associated demographics, and measures of performance. In Aim 2, we assess the hypothesis that deficits in comprehending speech in noise with unilateral hearing loss affect processing in non- auditory cognitive brain regions. We propose a functional imaging study of activity evoked by high and low predictability sentences in the presence and absence of multi-talker babble. We predict that compensating for degraded speech comprehension in noise involves greater activation of cognitive centers in temporo-parietal, inferior and dorsolateral frontal, and cingulate cortex in adults with unilateral hearing loss compared to those with normal hearing. In Aim 3, we examine the benefit of cochlear implantation for adults and children with asymmetric hearing loss and varied ages at onset of deafness and hearing histories in the poorer ear. We predict that even if one ear has partial hearing and the brain has learned to hear with a fairly good acoustic signal, age at onset of deafness in the poorer ear will be associated with outcome. In Aim 4, we identify factors in bilateral cochlear implant recipients that contribute to asymmetry in speech recognition between ears and reduced bilateral performance. In prelingually deaf children, we expect that a longer time between surgeries corresponds to larger asymmetries in speech recognition between ears and reduced bilateral performance. In postlingual adults, we predict that greater divergence in electrode placement between cochleas correlates with larger asymmetries in speech recognition between ears, reduced bilateral performance, and larger interaural differences in pitch percepts. To summarize, the proposed research program will probe the basis of behavioral variability and brain reorganization in unilateral hearing loss. Findings will determine how asymmetry in hearing affects behavioral outcomes and whether new considerations exist for early onset of unilateral deafness. Knowledge gained could influence decisions about treated ear, treatment types, and timing of treatment in children and adults with asymmetric hearing loss. Finally, results will enhance understanding of inter-cochlea electrode placement effects and potentially influence treatment decisions for bilateral implant recipients.