Split listening: A cognitive investigation of speech perception in adverse conditions

“认知听力”是指研究记忆和注意力过程如何在具有挑战性的条件下（例如，噪音，分心）促进言语感知。良好的认知能力是成功倾听的基础，这一说法在老年人和/或听力受损的听众中得到了广泛的证实。在这些小组中，高工作记忆（WM）容量与在嘈杂的语音任务中的更好表现有关。然而，对于听力正常的年轻人来说，认知能力和听力熟练程度之间的联系尚不清楚。这有四个原因：(1)年轻的、听力正常的成年人在认知测量上可能没有产生足够的个体差异来检测与听力表现的可靠关联。因此，大多数实验都是动力不足的。因此，认知听力研究需要更大的样本。(2)大多数研究集中在涉及能量掩蔽（EM）的不利条件，即信号退化的条件（如背景噪声）。有证据表明，对于本质上“数据有限”的任务，认知几乎没有帮助。因此，当挑战来自非电磁源时，也应调查认知倾听。(3)语义语境可以减轻不利听力条件的影响，从而使认知支持冗余或难以检测。因此，在模拟认知听力时应考虑语义语境。(4)听力表现（例如，一个句子中正确识别的单词数量）可能不是认知功能如何支持听力的最敏感的衡量标准，因为给定的表现水平可能会隐藏个人认知努力的有意义的差异。因此，在模拟认知听力时，应该包括一种心理努力的测量。本项目旨在系统地解决上述挑战，并全面了解听力正常的成年人的听力和认知过程之间的相互作用。该项目将包括大规模的在线实验和有针对性的实验室实验。在线实验将被用于检测个体WM差异对听力表现的任何调节作用，并将建立WM有助于语音理解和感知努力的条件。然后，这些条件将在实验室中进行更仔细的检查，使用听力努力的生理测量，任务诱发的瞳孔反应，这是“当下”（即听力期间）努力的公认标志。在线和室内实验都将使用我们新开发的“分音聆听”模式。在这个范例中，参与者必须同时跟踪两个声音。两种声音的相对空间位置是通过四个渐进的步骤来控制的，从并列，即听众的正前方（二分法）到完全侧向（二分法）。空间操作提供了一种强大的方法来对抗注意力驱动（即认知）的需求，即在二分型听力中，高电磁和低注意力需求vs在二分型听力中，低电磁和高注意力需求。我们实验室的试点数据证实了这种模式量化能量和认知过程之间竞争动态的能力。试点数据还表明，这种模式适用于大规模的在线测试。其参数操纵的EM和注意力需求使其成为瞳孔测量评估的理想候选人。总的来说，该项目提供了一种程序化的方法来研究努力倾听的认知和生理组成部分。在线实验中收集的关于个体差异的数据对于阐明传统听力测试之外对健康听力的认知贡献将是有价值的，这样做将为临床人群（例如听力损失和/或痴呆症患者）的有针对性干预铺平道路。

"Cognitive Listening" refers to the study of how memory and attention processes contribute to speech perception in challenging conditions (e.g., noise, distraction). The claim that good cognitive abilities underpin successful listening is broadly confirmed for older and/or hearing-impaired listeners. In those groups, high working memory (WM) capacity is associated with better performance in speech-in-noise tasks. For young adults with normal hearing, however, the link between cognition and listening proficiency is unclear. There are four reasons for this: (1) Young, normal-hearing adults might not generate sufficient individual variability on cognitive measures to detect reliable associations with listening performance. A majority of experiments are, thus, under-powered. Cognitive listening studies therefore need to be run with larger samples.(2) Most studies have focused on adverse conditions involving energetic masking (EM), that is, conditions in which the signal is degraded (e.g., background noise). Evidence suggests that cognition is of little help for tasks that are intrinsically "data-limited". Cognitive listening should therefore also be investigated when challenges arise from a non-EM source.(3) Semantic context can mitigate the effects of adverse listening conditions, hence making cognitive support redundant or difficult to detect. Semantic context should therefore be taken into account when modelling cognitive listening.(4) Listening performance (e.g., number of words in a sentence that are correctly recognised) may not be the most sensitive measure of how cognitive functions support listening because a given performance level can hide meaningful differences in individual cognitive effort. A measure of mental effort should therefore be included when modelling cognitive listening. The aim of this project is to systematically address the above challenges and provide a comprehensive understanding of the interaction between hearing and cognitive processes in adults with normal hearing. The project will include large-scale online experiments and targeted in-lab experiments. The online experiments will be powered to detect any modulating effects of individual WM differences on listening performance and will establish the conditions under which WM contributes to speech understanding and perceived effort. These conditions will then be inspected more closely in the lab using a physiological measure of listening effort, the task-evoked pupil response, a recognised marker of effort 'in the moment' (i.e., during listening). Both online and in-lab experiments will use our newly developed "split-listening" paradigm. In this paradigm, participants have to track two simultaneous voices. The relative spatial location of the two voices is manipulated in four incremental steps, from collocated, i.e., straight ahead of the listener (diotic), to fully lateralised (dichotic). The spatial manipulation provides a powerful way of pitting EM against attention-driven (i.e., cognitive) demands, with high EM and low attention demands in diotic listening vs low EM and high attention demands in dichotic listening. Pilot data from our lab have confirmed the ability of this paradigm to quantify the competing dynamics between energetic and cognitive processes. The pilot data have also shown that this paradigm is amenable to online testing on a large scale. Its parametric manipulation of EM and attention demands makes it an ideal candidate for pupillometric assessment. As a whole, the project offers a programmatic approach to the cognitive and physiological building blocks of effortful listening. The data on individual differences gathered in the online experiments will be valuable in elucidating the cognitive contributors to healthy hearing beyond the traditional hearing test and, in doing so, pave the way for targeted interventions in clinical populations (e.g., individuals with a hearing loss and/or dementia).