McKay Colette M
Bionics Institute, Melbourne, VIC, Australia.
Department of Medical Bionics, University of Melbourne, Melbourne, VIC, Australia.
Front Psychol. 2021 Jan 13;11:611517. doi: 10.3389/fpsyg.2020.611517. eCollection 2020.
Cochlear implants electrically stimulate surviving auditory neurons in the cochlea to provide severely or profoundly deaf people with access to hearing. Signal processing strategies derive frequency-specific information from the acoustic signal and code amplitude changes in frequency bands onto amplitude changes of current pulses emitted by the tonotopically arranged intracochlear electrodes. This article first describes how parameters of the electrical stimulation influence the loudness evoked and then summarizes two different phenomenological models developed by McKay and colleagues that have been used to explain psychophysical effects of stimulus parameters on loudness, detection, and modulation detection. The Temporal Model is applied to single-electrode stimuli and integrates cochlear neural excitation using a central temporal integration window analogous to that used in models of normal hearing. Perceptual decisions are made using decision criteria applied to the output of the integrator. By fitting the model parameters to a variety of psychophysical data, inferences can be made about how electrical stimulus parameters influence neural excitation in the cochlea. The Detailed Model is applied to multi-electrode stimuli, and includes effects of electrode interaction at a cochlear level and a transform between integrated excitation and specific loudness. The Practical Method of loudness estimation is a simplification of the Detailed Model and can be used to estimate the relative loudness of any multi-electrode pulsatile stimuli without the need to model excitation at the cochlear level. Clinical applications of these models to novel sound processing strategies are described.
人工耳蜗通过电刺激耳蜗中存活的听觉神经元，为重度或极重度聋人提供听力。信号处理策略从声信号中提取频率特异性信息，并将频段内的幅度变化编码为按频率拓扑排列的耳蜗内电极发出的电流脉冲的幅度变化。本文首先描述电刺激参数如何影响诱发的响度，然后总结了麦凯及其同事开发的两种不同的现象学模型，这些模型已被用于解释刺激参数对响度、检测和调制检测的心理物理学效应。时间模型应用于单电极刺激，并使用类似于正常听力模型中使用的中央时间积分窗口对耳蜗神经兴奋进行积分。使用应用于积分器输出的决策标准做出感知决策。通过将模型参数拟合到各种心理物理学数据，可以推断电刺激参数如何影响耳蜗中的神经兴奋。详细模型应用于多电极刺激，包括耳蜗水平上电极相互作用的影响以及积分兴奋与特定响度之间的转换。响度估计的实用方法是详细模型的简化版本，可用于估计任何多电极脉冲刺激相对响度，而无需对耳蜗水平的兴奋进行建模。本文还描述了这些模型在新型声音处理策略中的临床应用。
