Auditory nerve responses to electric pulse trains

听觉神经对电脉冲序列的反应

• 批准号: 7426363
• 负责人: CHARLES A MILLER
• 金额: $ 45.65万
• 依托单位: UNIVERSITY OF IOWA
• 依托单位国家: 美国
• 财政年份: 2005
• 资助国家: 美国
• 起止时间: 2005-08-15 至 2010-06-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/7426363
• 关键词: Accounting; Acoustic Nerve; Acoustics; Action Potentials; Address; Adopted; Advocate; Affect; Anatomy; Animal Model; Animals; Clinical; Clinical Research; Cochlear Implants; Code; Computer Simulation; Crackles; Data; Dimensions; Drops; Ear; Environment; Equilibrium; Evoked Potentials; Exhibits; Feedback; Felis catus; Fiber; Frequencies; Future; Goals; Hearing Impaired Persons; Implant; Individual; Knowledge; Link; Measures; Modeling; Music; Nerve; Nerve Degeneration; Nerve Fibers; Neurons; Numbers; Output; Pathology; Pattern; Performance; Physiologic pulse; Physiological; Physiology; Preparation; Property; Protocols documentation; Pulse Rates; Pulse taking; Range; Rate; Refractory; Reporting; Research; Research Personnel; Sampling; Severities; Signal Transduction; Simulate; Speech; Speech Perception; Stimulus; Techniques; Testing; Training; Work; base; clinically relevant; computerized data processing; deafness; design; improved; innovation; interest; nerve supply; neuroadaptation; novel; relating to nervous system; response; tool; trend

A trend in cochlear implants is the use of faster per-channel pulse carrier rates, promoted on the basis of increased information capacity. However, it is not clear that higher rates achieve this goal in most or ill individuals. Clinical studies present mixed results and research promoting high (e.g., 5000 pps) rales raises important questions. For example, while beneficial, desynchronizing, effects have been reported in many auditory nerve fibers, comparable numbers become adapted to the point of being unresponsive. Furthermore, physiologic dala have only been obtained from intact fibers, not from degenerated neurons typical of chronically deaf ears. Finally, while much is known about neural adaptation to acoustic stimuli, relatively little is known about electrical adaptation, even though the latter typically produces much larger functional changes. We hypothesize that at least part of the variability in performance with higher-rate carriers is due to across-user differences in the auditory nerve's response to high-rate stimuli. This research plan seeks to fill these gaps in our knowledge of how the auditory nerve encodes information presented as modulated pulse trains. Three Aims are proposed. Aim 1 will assess signal encoding in fibers excited by modulated carriers at rates relevant to modern and proposed speech processors. Data will be collected from intact and degenerated nerves for greater applicability to clinical cases. Fiber tracing techniques will help link physiology with anatomical status. Aim 2 will use that data to help develop a computational model of the nerve that accounts for many fiber properties (e.g., integration, refractoriness, and adaptation). This model wsll be used to predict the electrically evoked compound action potential (EC'AP) so that we can tesi: the capacity of ECAP measures to assess fiber functionality, a clinically relevant issue. Finally, Aim 3 will explore the feasibility of applying specific transforms to modulated trains to compensate for adaptation and refractory effects that limit information carried by modulated pulse trains. We expect the results of this work will guide future designs of cochlear-implant speech processors so that modulated stimuli can be better tailored to the encoding capacity of the user's auditory nerve.

人工耳蜗植入的一个趋势是使用更快的每通道脉冲载波速率，这是在增加信息容量的基础上促进的。然而，目前尚不清楚较高的发病率是否能在大多数患者中实现这一目标。临床研究呈现出好坏参半的结果，而促进高（例如，5000磅）发病率的研究提出了重要的问题。例如，虽然在许多听觉神经纤维中已经报道了有益的、不同步的影响，但相当数量的听觉神经纤维已经适应到没有反应的程度。此外，生理数据仅从完整的纤维中获得，而不是从慢性耳聋典型的退化神经元中获得。最后，虽然我们对神经对声刺激的适应了解很多，但相对而言