University of Cologne, Faculty of Medicine and University Hospital Cologne, Department of Otorhinolaryngology, Head and Neck Surgery, Audiology and Pediatric Audiology, Cochlear Implant Center, Germany.
Jean-Uhrmacher-Institute for Clinical ENT Research, University of Cologne, Germany.
Clin Neurophysiol. 2023 Oct;154:141-156. doi: 10.1016/j.clinph.2023.07.009. Epub 2023 Aug 6.
Hearing with a cochlear implant (CI) is difficult in noisy environments, but the use of noise reduction algorithms, specifically ForwardFocus, can improve speech intelligibility. The current event-related potentials (ERP) study examined the electrophysiological correlates of this perceptual improvement.
Ten bimodal CI users performed a syllable-identification task in auditory and audiovisual conditions, with syllables presented from the front and stationary noise presented from the sides. Brainstorm was used for spatio-temporal evaluation of ERPs.
CI users revealed an audiovisual benefit as reflected by shorter response times and greater activation in temporal and occipital regions at P2 latency. However, in auditory and audiovisual conditions, background noise hampered speech processing, leading to longer response times and delayed auditory-cortex-activation at N1 latency. Nevertheless, activating ForwardFocus resulted in shorter response times, reduced listening effort and enhanced superior-frontal-cortex-activation at P2 latency, particularly in audiovisual conditions.
ForwardFocus enhances speech intelligibility in audiovisual speech conditions by potentially allowing the reallocation of attentional resources to relevant auditory speech cues.
This study shows for CI users that background noise and ForwardFocus differentially affect spatio-temporal cortical response patterns, both in auditory and audiovisual speech conditions.
人工耳蜗（CI）使用者在噪声环境中听声困难，但使用降噪算法（特别是前向聚焦）可以提高言语可懂度。本事件相关电位（ERP）研究旨在探讨这种感知改善的电生理相关性。
10 名双耳植入 CI 的使用者在听觉和视听条件下执行音节识别任务，音节从前侧呈现，噪声从两侧呈现。使用 Brainstorm 进行 ERP 的时空评估。
CI 使用者表现出视听获益，表现为反应时间缩短，P2 潜伏期时颞区和枕区激活增强。然而，在听觉和视听条件下，背景噪声会干扰言语处理，导致反应时间延长，N1 潜伏期时听觉皮层激活延迟。然而，激活前向聚焦可缩短反应时间，降低聆听努力，并在 P2 潜伏期增强额上回激活，尤其是在视听条件下。
前向聚焦通过可能允许重新分配注意力资源到相关的听觉言语线索，从而增强视听言语条件下的言语可懂度。
本研究表明，对于 CI 使用者，背景噪声和前向聚焦会在听觉和视听言语条件下，对时空皮质反应模式产生不同的影响。
