Hearing Aids and Auditory Evoked Potentials

描述（由申请人提供）：尽管佩戴助听器的人数众多（620万；Kochkin, 2005），助听器放大对大脑的具体影响在很大程度上是未知的；然而，众所周知，中央听觉系统（CAS）作为听觉剥夺和刺激的功能而变化，在整个生命周期中根据个体可用的听觉输入进行重组。助听器放大是听觉刺激的一个例子，旨在检验放大对人类CAS的影响的实验开始出现。通过测量CAS对放大声音的反应，我们可以更多地了解听力损失和放大对CAS的影响，进而改善听觉康复的基础科学。因此，这项研究计划的长期目标是更好地理解听力损失的成年人放大声音的神经表征。理论上，当声音被助听器放大时，与无助听器的神经反应相比，神经反应模式的振幅（强度）应该更大，潜伏期（神经传导旅行时间）应该更短。这一理论是基于几十年的神经科学研究，该研究证明了电生理记录中强度的增量（小至2-3分贝）增加的影响（例如，Martin & Boothroyd, 2000; Rapin， Schimmel等，1966）；然而，最近在我们实验室进行的实验表明，情况并非如此。当助听器提供20 dB增益时，无助听器和辅助助听器的神经反应模式没有显著差异（Billings, Tremblay & Souza, 2006; Tremblay， Billings等，2006）。据推测，在助听器处理声音的方式和听觉系统编码之间发生了某种相互作用，在解释与助听器使用相关的CAS中的刺激相关效应之前，有必要了解这种相互作用。因此，我们介绍了一项研究计划，旨在检查助听器处理的声音输入与听力损失和非听力损失人群的神经编码之间的相互作用。具体目标是：(1)确定刺激强度和放大对正常听力参与者神经反应的影响，(2)确定听力受损个体的相同影响，以及(3)量化信号处理对刺激声学的影响。

DESCRIPTION (provided by applicant): Despite the large number of people who wear hearing aids (6.2 million; Kochkin, 2005), the specific effects of hearing aid amplification on the brain are largely unknown; however, it is known that the central auditory system (CAS) changes as a function of auditory deprivation and stimulation, reorganizing throughout the lifespan according to the auditory input that is available to the individual. Hearing aid amplification is one example of auditory stimulation, and experiments designed to examine the effect of amplification on the human CAS are beginning to emerge. By measuring CAS responses to amplified sound we can learn more about the effects of hearing loss and amplification on the CAS and, in turn, improve the science underlying auditory rehabilitation. Therefore, the long-term goal of this research program is to better understand the neural representation of amplified sound in adults with hearing loss. In theory, when sound is amplified by a hearing aid, neural response patterns should be larger in amplitude (strength) and shorter in latency (neural conduction travel-time) when compared with unaided neural responses. This theory is based on decades of neuroscience demonstrating the effects of incremental (as small as 2-3 dB) increases in intensity on electrophysiological recordings (e.g., Martin & Boothroyd, 2000; Rapin, Schimmel, et al., 1966); however, recent experiments conducted in our laboratory indicate that this is not the case. When 20 dB of gain was provided by a hearing aid, there were no significant differences between unaided and aided neural responses patterns (Billings, Tremblay & Souza, 2006; Tremblay, Billings et al., 2006). Presumably, some sort of interaction is occurring between the way sound is processed by the hearing aid and encoded in the auditory system, and it is necessary to understand this interaction before stimulation-related effects in the CAS, associated with hearing aid use, can be interpreted. Therefore, we introduce a program of research that examines the interaction between hearing-aid- processed acoustic input and neural encoding in people with and without hearing loss. The specific aims are: (1) determine the effects of stimulus intensity and amplification on neural responses in normal-hearing participants, (2) determine the same effects in hearing-impaired individuals, and (3) quantify signal- processing effects on stimuli acoustics using in-the-canal acoustic recordings.