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: 8978430
• 负责人: Brian Buechel
• 金额: $ 3.55万
• 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 2017-07-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/8978430
• 关键词: Acoustics; Air; Animal Behavior; Animal Model; Animals; Behavioral; Bilateral; 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; 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串（>30 pps）的耳间时间差（ITD）感知灵敏度较差，这些脉冲串在现代CI处理器中用作载波。其结果是，CI性能下降的任务，是依赖于双耳线索，如声音定位和语音接收在嘈杂的环境中。因此，需要改进感知ITD灵敏度的新CI处理策略。将双耳相干抖动引入高速率普尔斯序列已被证明可改善CI用户的ITD敏感性，并且已在下丘（IC）中观察到该效应的神经相关性。IC中的神经元对高速率周期性脉冲串的响应较弱且ITD敏感性较差，但抖动的脉冲串包含偶尔的脉冲间间隔（IPI），其可以在适应的神经元中引起尖峰，从而增加触发速率并恢复ITD敏感性。我们将测试一个新的处理策略的概念，在这个建议，旨在提高知觉和神经ITD的灵敏度与双边CI。在该策略中，将额外的脉冲插入到周期性脉冲串中，以在刺激中的特定时间点引入短IPI。在目的1中，我们将使用双侧CI的清醒动物模型来确定短IPIs对IC神经元的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的敏感性，我们将研究什么刺激参数的短IPI优化这种改善整个IC神经元的人口。在目标2中，我们将把短IPI引入到由语音包络进行幅度调制的脉冲串中，以近似于由临床CI处理器提供的刺激。我们将再次在我们的动物模型中表征IC神经元中的神经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可以增加调制脉冲串的神经ITD敏感性。最后，在目标3中，我们将在我们的动物模型中使用经典条件反射任务评估短IPI对感知ITD辨别的影响。我们预测，动物将更容易区分ITD的高速率脉冲序列时，他们包含短IPIs。这些实验的总体目标是评估使用短IPI来改善感知ITD灵敏度的新型刺激策略的潜力。这种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。