Arzounian Dorothée, Guérit François, Deeks John M, Garcia Charlotte, de Groote Evelien, Bance Manohar, Carlyon Robert P
Cambridge Hearing Group, MRC Cognition & Brain Sciences Unit, University of Cambridge, 15 Chaucer Rd, Cambridge, CB2 7EF, United Kingdom.
Cambridge Hearing Group, MRC Cognition & Brain Sciences Unit, University of Cambridge, 15 Chaucer Rd, Cambridge, CB2 7EF, United Kingdom.
Hear Res. 2025 Aug;464:109338. doi: 10.1016/j.heares.2025.109338. Epub 2025 Jun 16.
Studies investigating objective measures of auditory perception when using cochlear implants (CIs) differ in the stimuli used and in the neural response measured. The present study aims to disentangle the effects of response type and of stimulus type on neural response properties. We report three measures corresponding with separate neural latencies, all collected from the same 19 CI recipients and with the same stimulus, consisting of a continuous low-rate electrical pulse train of about 40 pulses per second (pps). These measures comprise the electrically evoked compound action potential (eCAP), auditory brainstem response (eABR), and auditory steady-state response (eASSR), having putative neural generators in peripheral (auditory nerve), subcortical (brainstem), and thalamo-cortical auditory regions, respectively. When assessing correlations across CI recipients, we found that the growth of eASSR amplitude with stimulus level was correlated with that of eCAP amplitude and predictive of the just-noticeable-to-comfortable electrical dynamic range, as measured through behavioral loudness scaling. Additionally, we compared eASSRs measured with the ∼40-pps stimulus and with a high-rate (500-pps) pulse train modulated in amplitude at rates around 40 Hz, and found that both showed similar recipient-specific effects of stimulation rate on response phase and amplitude. Our results highlight that neural responses to different electrical stimuli and at different central processing stages share common idiosyncratic properties, and support the validity of eASSRs for loudness-growth estimation in CI recipients.
研究人工耳蜗（CI）时，关于听觉感知客观测量的研究在所用刺激和所测量的神经反应方面存在差异。本研究旨在厘清反应类型和刺激类型对神经反应特性的影响。我们报告了三种与不同神经潜伏期相对应的测量方法，所有测量均来自19名相同的CI接受者，且使用相同的刺激，该刺激由每秒约40个脉冲（pps）的连续低速率电脉冲序列组成。这些测量方法包括电诱发复合动作电位（eCAP）、听觉脑干反应（eABR）和听觉稳态反应（eASSR），其假定的神经发生器分别位于外周（听神经）、皮层下（脑干）和丘脑 - 皮层听觉区域。在评估CI接受者之间的相关性时，我们发现eASSR振幅随刺激水平的增长与eCAP振幅的增长相关，并且可以预测通过行为响度标度测量的刚刚可察觉至舒适的电动态范围。此外，我们比较了用约40 pps刺激和以约40 Hz速率进行幅度调制的高速率（500 pps）脉冲序列测量的eASSR，发现两者在刺激速率对反应相位和振幅的接受者特异性影响方面表现相似。我们的结果突出表明，对不同电刺激以及在不同中枢处理阶段的神经反应具有共同的特质属性，并支持eASSR在CI接受者响度增长估计中的有效性。
