The auditory brainstem response (ABR) is a valuable clinical tool for objective hearing assessment, which is conventionally detected by averaging neural responses to thousands of short stimuli. Progressing beyond these unnatural stimuli, brainstem responses to continuous speech presented via earphones have been recently detected using linear temporal response functions (TRFs). Here, we extend earlier studies by measuring subcortical responses to continuous speech presented in the sound-field, and assess the amount of data needed to estimate brainstem TRFs. Electroencephalography (EEG) was recorded from 24 normal hearing participants while they listened to clicks and stories presented via earphones and loudspeakers. Subcortical TRFs were computed after accounting for non-linear processing in the auditory periphery by either stimulus rectification or an auditory nerve model. Our results demonstrated that subcortical responses to continuous speech could be reliably measured in the sound-field. TRFs estimated using auditory nerve models outperformed simple rectification, and 16 minutes of data was sufficient for the TRFs of all participants to show clear wave V peaks for both earphones and sound-field stimuli. Subcortical TRFs to continuous speech were highly consistent in both earphone and sound-field conditions, and with click ABRs. However, sound-field TRFs required slightly more data (16 minutes) to achieve clear wave V peaks compared to earphone TRFs (12 minutes), possibly due to effects of room acoustics. By investigating subcortical responses to sound-field speech stimuli, this study lays the groundwork for bringing objective hearing assessment closer to real-life conditions, which may lead to improved hearing evaluations and smart hearing technologies.

中文翻译：

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将皮层下脑电图响应扩展到声场的连续语音


听觉脑干反应（ABR）是客观听力评估的一个有价值的临床工具，通常通过平均对数千个短刺激的神经反应来检测。除了这些不自然的刺激之外，最近使用线性时间响应函数（TRF）检测到了脑干对通过耳机呈现的连续语音的反应。在这里，我们通过测量皮层下对声场中呈现的连续语音的反应来扩展早期的研究，并评估估计脑干 TRF 所需的数据量。 24 名听力正常的参与者在聆听通过耳机和扬声器播放的点击声和故事时，记录了他们的脑电图 (EEG)。通过刺激校正或听觉神经模型考虑听觉外围的非线性处理后计算皮层下 TRF。我们的结果表明，可以在声场中可靠地测量皮层下对连续语音的反应。使用听觉神经模型估计的 TRF 优于简单校正，16 分钟的数据足以让所有参与者的 TRF 显示耳机和声场刺激的清晰波 V 峰值。连续语音的皮层下 TRF 在耳机和声场条件以及点击 ABR 下都高度一致。然而，与耳机 TRF（12 分钟）相比，声场 TRF 需要稍多的数据（16 分钟）才能实现清晰的波 V 峰值，这可能是由于室内声学的影响。通过研究皮层下对声场言语刺激的反应，这项研究为使客观听力评估更接近现实生活条件奠定了基础，这可能会导致听力评估和智能听力技术的改进。