Institute for Systems Research, University of Maryland, College Park, MD 20742, USA.
Department of Electrical and Computer Engineering, University of Maryland, College Park, MD 20742, USA.
Trends Hear. 2024 Jan-Dec;28:23312165241245240. doi: 10.1177/23312165241245240.
Listening to speech in noise can require substantial mental effort, even among younger normal-hearing adults. The task-evoked pupil response (TEPR) has been shown to track the increased effort exerted to recognize words or sentences in increasing noise. However, few studies have examined the trajectory of listening effort across longer, more natural, stretches of speech, or the extent to which expectations about upcoming listening difficulty modulate the TEPR. Seventeen younger normal-hearing adults listened to 60-s-long audiobook passages, repeated three times in a row, at two different signal-to-noise ratios (SNRs) while pupil size was recorded. There was a significant interaction between SNR, repetition, and baseline pupil size on sustained listening effort. At lower baseline pupil sizes, potentially reflecting lower attention mobilization, TEPRs were more sustained in the harder SNR condition, particularly when attention mobilization remained low by the third presentation. At intermediate baseline pupil sizes, differences between conditions were largely absent, suggesting these listeners had optimally mobilized their attention for both SNRs. Lastly, at higher baseline pupil sizes, potentially reflecting overmobilization of attention, the effect of SNR was initially reversed for the second and third presentations: participants initially appeared to disengage in the harder SNR condition, resulting in reduced TEPRs that recovered in the second half of the story. Together, these findings suggest that the unfolding of listening effort over time depends critically on the extent to which individuals have successfully mobilized their attention in anticipation of difficult listening conditions.
在噪声中听语音可能需要大量的心理努力，即使是在年轻的正常听力成年人中也是如此。研究表明，任务诱发的瞳孔反应（TEPR）可以跟踪在噪声增加时识别单词或句子所需要付出的努力的增加。然而，很少有研究探讨在更长、更自然的语音片段中倾听努力的轨迹，或者在多大程度上对即将到来的听力困难的期望会调节 TEPR。17 名年轻的正常听力成年人在两种不同信噪比（SNR）下连续听 60 秒的有声读物片段，重复三遍，同时记录瞳孔大小。在持续的听力努力方面，信噪比、重复和基础瞳孔大小之间存在显著的相互作用。在较低的基础瞳孔大小下，可能反映出注意力动员较低，在较难的 SNR 条件下 TEPR 更持久，特别是当注意力动员在第三次呈现时仍然较低时。在中等基础瞳孔大小下，条件之间的差异基本不存在，这表明这些听众已经为两种 SNR 最佳地动员了他们的注意力。最后，在较高的基础瞳孔大小下，可能反映出注意力过度动员，在第二次和第三次呈现时，SNR 的影响最初被逆转：参与者最初似乎在较难的 SNR 条件下分心，导致 TEPR 降低，在故事的后半部分恢复。总的来说，这些发现表明，随着时间的推移，倾听努力的展开在很大程度上取决于个体在预期困难的听力条件下成功动员注意力的程度。
