Encoding Temporal Fine Structure for Cochlear Implants

项目总结 这项工作的目标是改善人工耳蜗使用者的音乐和语音感知。相关的健康问题 结果就是他们的生活质量。这项建议的重点是人工耳蜗术后使用者如何学会使用 时间精细结构，如果作为音乐或音调的清晰和一致的提示提供的话。从历史上看，人工耳蜗 植入物丢弃了时间精细结构，仅传输了相对较慢的定时信息 包络波动。已经尝试将颞叶细微结构恢复到人工耳蜗术中 刺激，但尚不清楚之前的尝试是否受到实施、缺乏经验或 与生俱来的生理学。建议的方法是独特的，因为它检查了知觉和生理 当颞叶细微结构恢复时发生的可塑性。拟议的研究分为两个目标， 它检查了提供音调感的刺激位置和速度的相对显著程度(目标1)，以及 与传统方法相比，动态频率刺激的显著程度(目标2)。这两个目标都结合了感性 学习、计算机控制的电极心理物理学、电生理学和计算神经建模 目的：研究人工耳蜗术后患者音高知觉的可塑性。 目的1研究人工耳蜗术后的知觉可塑性和生理可塑性与人工耳蜗术中的位置和频率的关系 刺激。人工耳蜗使用者会听到随着刺激率的增加而增加的音调，但这 300赫兹以上的效应很难测量。人工耳蜗术后心理物理敏感性的研究最多 刺激率没有考虑知觉学习。初步结果显示，音调感 提供的刺激率随着训练的增加而提高。这项拟议的研究考察了知觉敏感性和 在整个交叉训练研究中进行生理编码，并根据地点和音高提供训练 刺激率。测试的主要假设是，人工耳蜗使用者有潜在的听到音调的能力 与刺激率有关，但他们需要培训来学习如何使用这些新信息。 目标2是确定动态心率刺激是否提供更好的敏感性和更好的生理 基频编码与传统的基于幅度的刺激方法的比较 恒速刺激的调制。在正常生理学中，听觉神经活动期锁定在颞叶 声音的精细结构。由于人工耳蜗通常会丢弃这一信息，因此目前尚不清楚人工耳蜗术的效果如何 如果提供植入物，植入者可以学习使用它。目的2重点比较动态频率刺激和动态频率刺激 其中与传统方法相比，动态调整刺激率以传达时间精细结构 方法采用恒速刺激调幅的方法。主要的假设是动态的- 与幅度相比，速率刺激提供更好的音调敏感度和更好的生理编码 恒速刺激的调制。

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.