Effects of Early Conductive Hearing Loss on Auditory Behavior and Information Pro

描述（由申请人提供）：在发育过程中导致传导性听力损失（CHL）的慢性耳部感染可导致听觉功能的长期缺陷，包括与双耳听力相关的功能。这些包括在空间中定位声音，在嘈杂环境中检测声音以及获得言语和语言方面的障碍-所有这些任务都需要正确整合双耳的信息。特别地，包括耳间时间（ITD）和电平（ILD）差异线索的声音位置的线索，在很大程度上依赖于来自双耳的声音信息的正确输入。由于CHL可以衰减和延迟传入的声音，因此可以有效地改变声音位置的线索。在生命早期的发育敏感期存在CHL可能会导致双耳听觉系统适应改变双耳线索的位置，而不是正常的线索，从而提供了一个可能的基础上，临床观察到的持续性空间听力问题的儿童。然而，这些持续影响的确切机制尚不完全清楚。一些动物研究试图阐明听觉系统发育中的中枢机制，但很少有全面研究早期CHL的长期行为后果，也没有充分研究其对声音位置线索神经信息处理的影响。因此，本研究的主要目的是了解早期CHL对（1）行为声音定位能力和（2）声音定位敏感神经元信息处理的影响。为了实现这些目标，拟议研究的具体目的是（1）评估单侧CHL饲养的成年豚鼠的行为声音定位能力和（2）评估单侧CHL饲养的同一动物下丘（IC）神经元的信息处理能力。实验将结合行为和在体电生理技术，共同评估早期CHL对双耳听觉系统的影响。我们假设，早期CHL将导致持续的声音定位缺陷相对于正常对照动物，以及损害 在ILD提示声音定位的神经信息处理中。总的来说，我们预计更大的行为缺陷与ILD信息处理的减少有关，这可能为在发育早期经历慢性耳部感染的儿童中观察到的持续性空间听力缺陷提供了可能的基础。拟议的工作是专门设计来支持NIDCD的使命，通过推进发展中的双耳听觉系统与儿童听力障碍的临床相关性的基本理解。

DESCRIPTION (provided by applicant): Chronic ear infections resulting in a conductive hearing loss (CHL) during development can produce long-term deficits in auditory functions, including those involved with binaural hearing. These include impairment in locating sounds in space, detecting sounds in noisy environments, as well as acquisition of speech and language- all tasks that require the proper integration of information from both ears. In particular, the cue to sound location, which include interaural time (ITD) and level (ILD) difference cues, rely heavily on the proper input of sound information from both ears. Since CHL can attenuate and delay incoming sounds, the cues to sound location can thus be effectively altered. The presence of a CHL during developmental sensitive periods early in life may result in the binaural auditory system adapting to altered binaural cues to location instead of the normal cues, thus providing a possible basis for the persistent spatial hearing problems observed clinically in children. The exact mechanism underlying these persistent effects, however, is not entirely known. Several animal studies have attempted to elucidate the central mechanisms in the developing auditory system, yet few have comprehensively examined the long-term behavioral consequences of early CHL, and none have fully examined its effects on neural information processing of cues to sound location. Therefore, the main goal of this research is to understand the effects of early CHL on (1) behavioral sound localization ability and (2) information processing by neurons sensitive to sound location. Towards these goals, the Specific Aims of the proposed research are to (1) assess behavioral sound localization ability in adult guinea pigs reared with a unilateral CHL and (2) to evaluate the information processing capabilities of neurons in the inferior colliculus (IC) in the same animals reared with a unilateral CHL. Experiments will integrate both behavior and in vivo electrophysiological techniques to jointly assess the effects of early CHL on the binaural auditory system. We hypothesize that early CHL will result in persistent sound localization deficits relative to normal control animals, as well as an impairment in neural information processing of the ILD cue to sound location. In general, we expect greater behavioral deficits to be associated with a reduction in ILD information processing, and that this may provide a possible basis for the persistent spatial hearing deficits observed in children who experienced chronic ear infections early in development. The proposed work is specifically designed to support the mission of NIDCD by advancing the basic understanding of the developing binaural auditory system with clinical relevance to childhood hearing disorders.