Improved binaural stimulation strategy for bilateral cochlear implants

改进双侧人工耳蜗植入的双耳刺激策略

• 批准号: 9077051
• 负责人: Brian Buechel
• 金额: $ 1.35万
• 依托单位: HARVARD MEDICAL SCHOOL
• 依托单位国家: 美国
• 财政年份: 2015
• 资助国家: 美国
• 起止时间: 2015-08-01 至 2016-11-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/9077051
• 关键词: Acoustics; Air; Animal Behavior; Animal Model; Animals; Behavioral; Bilateral; Binaural; Blinking; Clinical; Cochlear Implants; Contralateral; Cornea; Cues; Data; Discrimination; Drops; Ear; Environment; Female; Frequencies; Goals; Hearing; Individual; Inferior Colliculus; Lead; Location; Methods; Modeling; Neurons; Noise; Oryctolagus cuniculus; Outcome; Perception; Performance; Physiologic pulse; Population; Positioning Attribute; Preparation; Probability; Process; Pulse Rates; Quality of life; Research; Sampling; Side; Sound Localization; Speech; Speech Intelligibility; Stimulus; Testing; Time; Training; Translating; Voice; Width; awake; base; behavioral response; blink reflexes; classical conditioning; conditioning; hearing impairment; improved; local maxima; male; neural correlate; neurophysiology; novel; public health relevance; relating to nervous system; research study; response; simulation; sound; stimulus interval

 DESCRIPTION (provided by applicant): Bilateral cochlear implant (CI) users have poor perceptual sensitivity to interaural time differences (ITD) of high-rate periodic pulse trains (>30 pps), which are used as carriers in modern CI processors. As a result, CI performance is degraded for tasks that are dependent on binaural cues such as sound localization and speech reception in noisy environments. Therefore, there is a need for new CI processing strategies that improve perceptual ITD sensitivity. Introducing binaurally coherent jitter into high-rate puls trains has been shown to improve ITD sensitivity in CI users, and neural correlates of this effect have been observed in the inferior colliculus (IC). Neurons in the IC respond weakly and with poor ITD sensitivity to high-rate periodic pulse trains, but jittered trains contain occasional shot inter-pulse intervals (IPIs) that can elicit spikes in adapted neurons, thereby increasing the firig rate and restoring ITD sensitivity. We will test the concept of a new processing strategy in this proposal aimed at improving both perceptual and neural ITD sensitivity with bilateral CI. In this strategy, extra pulses are inserted into periodic pulse trains to introduce short IPIs at specific time points in the stimulus. In Aim 1, we will determine the effect of short IPIs on ITD sensitivit of IC neurons using an awake animal model of bilateral CIs. Our preliminary data suggest short IPIs can improve neural ITD sensitivity, and we will investigate what stimulus parameters of short IPIs optimize this improvement across the population of IC neurons. In Aim 2, we will introduce short IPIs into pulse trains that are amplitude modulated by speech envelopes to approximate the stimuli delivered by clinical CI processors. We will again characterize neural ITD sensitivity in IC neurons in our animal model, which will allow us to investigate how short IPIs could be incorporated into a clinical stimulation strategy. Preliminary data suggest short IPIs can increase neural ITD sensitivity with modulated pulse trains. Lastly, in Aim 3 we will evaluate the effect of short IPIs on perceptual ITD discrimination with a classical conditioning task in our animal model. We predict that the animals will more readily discriminate the ITD of high-rate pulse trains when they contain short IPIs. The overall goal of these experiments is to evaluate the potential for a novel stimulation strategy that uses short IPIs to improve perceptual ITD sensitivity. This strategy could lead to better outcomes for CI users by improving sound localization and speech reception in noisy environments.

 描述（由申请人提供）：双侧人工耳蜗 (CI) 用户对高速率周期性脉冲序列 (>30 pps) 的耳间时间差 (ITD) 的感知敏感性较差，这些脉冲序列在现代 CI 处理器中用作载体。因此，对于依赖双耳线索的任务（例如噪声环境中的声音定位和语音接收），CI 性能会下降。因此，需要新的 CI 处理策略来提高感知 ITD 敏感性。将双耳相干抖动引入高速脉冲序列已被证明可以提高 CI 用户的 ITD 敏感性，并且在下丘 (IC) 中观察到了这种效应的神经相关性。 IC 中的神经元对高速率周期性脉冲序列响应较弱且 ITD 敏感性较差，但抖动脉冲序列包含偶尔的脉冲间间隔 (IPI)，可以在适应的神经元中引起尖峰，从而提高放电速率并恢复 ITD 敏感性。我们将在本提案中测试新处理策略的概念，旨在通过双边 CI 提高感知和神经 ITD 敏感性。在此策略中，额外的脉冲被插入到周期性脉冲序列中，以在刺激的特定时间点引入短 IPI。在目标 1 中，我们将使用双边 CI 的清醒动物模型确定短 IPI 对 IC 神经元 ITD 敏感性的影响。我们的初步数据表明，短 IPI 可以提高神经 ITD 敏感性，我们将研究短 IPI 的哪些刺激参数可以优化 IC 神经元群体的这种改善。在目标 2 中，我们将在脉冲序列中引入短 IPI，这些脉冲序列通过语音包络进行幅度调制，以近似临床 CI 处理器传递的刺激。我们将再次表征动物模型中 IC 神经元的神经 ITD 敏感性，这将使我们能够研究如何将短 IPI 纳入临床刺激策略。初步数据表明，短 IPI 可以通过调制脉冲序列提高神经 ITD 敏感性。最后，在目标 3 中，我们将通过动物模型中的经典调节任务来评估短 IPI 对知觉 ITD 辨别的影响。我们预测，当高速率脉冲序列包含短 IPI 时，动物将更容易辨别它们的 ITD。这些实验的总体目标是评估一种新颖的刺激策略的潜力，该策略使用短 IPI 来提高感知 ITD 敏感性。该策略可以通过改善嘈杂环境中的声音定位和语音接收来为 CI 用户带来更好的结果。