Encoding Temporal Fine Structure for Cochlear Implants

项目摘要 这项工作的目标是改善人工耳蜗用户的音乐和语音感知。相关卫生 结果是他们的生活质量。这项建议的重点是如何以及人工耳蜗植入用户可以学习使用 时间精细结构，如果提供作为音乐或音高的清晰和一致的线索。历史上，耳蜗 植入物已经丢弃了时间精细结构并且仅传输了相对慢的时间信息， 包络波动已经尝试将颞部精细结构恢复到人工耳蜗中 刺激，但目前还不清楚以前的尝试是否受到实施，缺乏经验，或 是生理学上固有的。所提出的方法是独特的，因为它检查了知觉和生理 当时间精细结构恢复时发生的可塑性。拟议的研究分为两个目标， 其检查用于提供音高感的刺激位置和速率的相对显著性（Aim 1）， 与传统方法相比，动态速率刺激的显著性（目标2）。这两个目标联合收割机 学习、计算机控制电极心理物理学、电生理学和计算神经建模 以表征人工耳蜗使用者的音高感知的可塑性。 目的1探讨人工耳蜗植入位置和频率对听觉和生理的影响 刺激.耳蜗植入体用户听到与增加的刺激速率相关联的增加的音调，但是这 在300 Hz以上很难测量效果。大多数关于人工耳蜗植入的心理物理敏感性的研究 刺激速率没有考虑知觉学习。初步结果显示， 提供的刺激率随着训练而提高。拟议的研究检查知觉敏感性， 通过交叉训练研究的生理编码，基于位置和 刺激率。测试的主要假设是，人工耳蜗植入者具有潜在的听音高的能力 与刺激率相关，但他们需要培训来学习如何使用这些新信息。 目的2是确定动态速率刺激是否提供更好的灵敏度和更好的生理刺激。 与基于幅度的常规刺激方法相比，基频编码 恒定速率刺激的调制。在正常生理学中，神经活动相位锁定在颞叶。 声音的细微结构。由于耳蜗植入物通常会丢弃这些信息，因此不知道耳蜗植入物的效果如何。 如果提供的话，植入用户可以学习使用它。目标2着重于动态速率刺激与 其中与常规的刺激速率相比， 基于恒定速率刺激的幅度调制的方法。主要假设是动态的- 与幅度相比，速率刺激提供更好的音调灵敏度和更好的生理编码 恒定速率刺激的调制。

PROJECT SUMMARY The goal of this work is to improve music and speech perception for cochlear implant users. The relevant health outcome is their quality of life. This proposal focuses on how well cochlear implant users can learn to use temporal fine structure if provided as a clear and consistent cue for music or voice pitch. Historically, cochlear implants have discarded temporal fine structure and have only transmitted timing information of relatively slow envelope fluctuations. Attempts have been made to restore temporal fine structure into cochlear implant stimulation, but it is unclear whether previous attempts were limited by implementation, lack of experience, or inherently by physiology. The proposed approach is unique in that it examines the perceptual and physiological plasticity that occurs when temporal fine structure is restored. Proposed research is organized into two aims, which examine the relative salience of stimulation place and rate for providing a sense of pitch (Aim 1) and the salience of dynamic-rate stimulation compared to conventional methods (Aim 2). Both aims combine perceptual learning, computer-controlled electrode psychophysics, electrophysiology, and computational neural modeling to characterize the plasticity of pitch perception in cochlear implant users. Aim 1 examines the perceptual and physiological plasticity associated with place and rate of cochlear implant stimulation. Cochlear implant users hear an increasing pitch associated with increasing stimulation rate, but this effect is difficult to measure above 300 Hz. Most studies of psychophysical sensitivity to cochlear implant stimulation rate have not considered perceptual learning. Preliminary results show that the sense of pitch provided by stimulation rate improves with training. The proposed research examines perceptual sensitivity and physiological encoding throughout a crossover training study with training provided for pitch based on place and rate of stimulation. The primary hypothesis tested is that cochlear implant users have a latent ability to hear pitch associated with stimulation rate, but they require training to learn how to use this new information. Aim 2 is to determine whether dynamic-rate stimulation provides better sensitivity and better physiological encoding of fundamental frequency compared to conventional stimulation methods based on amplitude modulation of constant-rate stimulation. In normal physiology, auditory-nerve activity phase locks to the temporal fine structure of sound. Since cochlear implants typically discard this information, it is unknown how well cochlear implant users can learn to use it if provided. Aim 2 focuses on the comparison between dynamic-rate stimulation in which stimulation rate is dynamically adjusted to convey temporal fine structure compared to conventional methods based on amplitude modulation of constant-rate stimulation. The primary hypothesis is that dynamic- rate stimulation provides better pitch sensitivity and better physiological encoding compared to amplitude modulation of constant-rate stimulation.