Department of Health Science and Technology, Integrative Neuroscience, Aalborg University, Aalborg, Denmark.
Department of Health Science and Technology, Center for Neuroplasticity and Pain, Aalborg University, Aalborg, Denmark.
Ear Hear. 2024;45(3):721-729. doi: 10.1097/AUD.0000000000001464. Epub 2024 Jan 30.
Background noise and linguistic violations have been shown to increase the listening effort. The present study aims to examine the effects of the interaction between background noise and linguistic violations on subjective listening effort and frontal theta oscillations during effortful listening.
Thirty-two normal-hearing listeners participated in this study. The linguistic violation was operationalized as sentences versus random words (strings). Behavioral and electroencephalography data were collected while participants listened to sentences and strings in background noise at different signal to noise ratios (SNRs) (-9, -6, -3, 0 dB), maintained them in memory for about 3 sec in the presence of background noise, and then chose the correct sequence of words from a base matrix of words.
Results showed the interaction effects of SNR and speech type on effort ratings. Although strings were inherently more effortful than sentences, decreasing SNR from 0 to -9 dB (in 3 dB steps), increased effort rating more for sentences than strings in each step, suggesting the more pronounced effect of noise on sentence processing that strings in low SNRs. Results also showed a significant interaction between SNR and speech type on frontal theta event-related synchronization during the retention interval. This interaction indicated that strings exhibited higher frontal theta event-related synchronization than sentences at SNR of 0 dB, suggesting increased verbal working memory demand for strings under challenging listening conditions.
The study demonstrated that the interplay between linguistic violation and background noise shapes perceived effort and cognitive load during speech comprehension under challenging listening conditions. The differential impact of noise on processing sentences versus strings highlights the influential role of context and cognitive resource allocation in the processing of speech.
背景噪声和语言违规已被证明会增加听力努力。本研究旨在考察背景噪声与语言违规之间的相互作用对努力倾听时主观听力努力和额部θ振荡的影响。
32 名正常听力的参与者参加了这项研究。语言违规被操作化为句子与随机单词（字符串）之间的差异。当参与者在不同信噪比（SNR）（-9、-6、-3、0 dB）的背景噪声下听句子和字符串时，收集了行为和脑电图数据，在背景噪声存在的情况下将它们保持在记忆中约 3 秒，然后从单词库中选择正确的单词序列。
结果显示 SNR 和语音类型对努力评分的交互作用。尽管字符串本身比句子更费力，但 SNR 从 0 降至-9 dB（每 3 dB 一步）时，句子的努力评分增加幅度大于每个步骤中的字符串，这表明噪声对句子处理的影响更为明显，而在低 SNR 下的字符串。结果还显示，在保留间隔期间，SNR 和语音类型之间存在显著的交互作用，影响额部θ事件相关同步。这种相互作用表明，在 SNR 为 0 dB 时，字符串比句子表现出更高的额部θ事件相关同步，这表明在具有挑战性的听力条件下，字符串对言语工作记忆的需求增加。
该研究表明，在具有挑战性的听力条件下，语言违规与背景噪声之间的相互作用塑造了感知努力和认知负荷。噪声对处理句子与字符串的不同影响突出了语境和认知资源分配在言语处理中的重要作用。
