Individual Differences in Cognition and Perception Predict Neural Processing of Speech in Noise for Audiometrically Normal Listeners.

ABSTRACT Individuals with normal hearing exhibit considerable variability in their capacity to understand speech in noisy environments. Previous research suggests the cause of this variance may be due to individual differences in cognition and auditory perception. To investigate the impact of cognitive and perceptual differences on speech comprehension, 25 adult human participants with normal hearing completed numerous cognitive and psychoacoustic tasks including the Flanker, Stroop, Trail Making, Reading Span, and temporal fine structure (TFS) tests. They also completed a continuous multi-talker spatial attention task while neural activity was recorded using electroencephalography (EEG). The auditory cortical N1 response was extracted as a measure of neural speech encoding during continuous speech listening using an engineered “chirped-speech” (Cheech) stimulus. We compared N1 component morphologies of target and masker speech stimuli to assess neural correlates of attentional gains while listening to concurrently played short story narratives. Performance on cognitive and psychoacoustic tasks were used to predict N1 component amplitude differences between attended and unattended speech using multiple regression. Results show inhibitory control and working memory abilities can predict N1 amplitude differences between the target and masker stories. Interestingly, none of the cognitive and psychoacoustic predictors correlated with behavioral speech-in-noise listening performance in the attention task, suggesting that neural measures may be more sensitive measures of cognitive and auditory processing as compared to behavioral measures alone. SIGNIFICANCE STATEMENT These findings contribute to our understanding of how cognition affects the neural mechanisms of speech perception. Specifically, our results highlight the complex interplay between cognitive abilities and neural encoding of speech in challenging listening environments with multiple speakers. By incorporating these additional measures of cognition, we can achieve a more comprehensive understanding of an individual’s speech perception abilities, even in individuals with normal hearing. This approach could lead to earlier detection of hearing issues and more personalized interventions, ultimately enhancing communication outcomes for those with hearing difficulty.