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Variations in alpha oscillations and speech evoked responses with different background sound types during performance on a speech-in-noise task

Poster Session A - Saturday, March 29, 2025, 3:00 – 5:00 pm EDT, Back Bay Ballroom/Republic Ballroom

Heather L. Read¹ (heather.read@uconn.edu), Tylor J. Harlow², Laila Almotwaly³; ¹University of Connecticut

In healthy individuals, cyclic inhibition associated with alpha oscillations serves to suppress cortical processing of task-irrelevant and ignored sensory stimuli (Bonnefond et al., 2017; Foxe et al., 2011). Accordingly, electroencephalogram (EEG) recordings find an anticipatory increase in alpha levels with onset of ignored background sounds followed by a subsequent decrease in alpha with onset of attended foreground speech sounds (Dimitrijevic et al., 2017). Other studies find the speech evoked response potential (ERP) and temporal response function (TRF) amplitudes are predictive of speech-in-noise task performance (Kim et al., 2021; Muncke et al., 2022 ). Here, we quantify changes in alpha and evoked responses associated with performance of a speech-in-noise task that includes six variations in background sound type. As in prior studies, we find alpha power increases with onset of the to-be-ignored background sounds and decreases with onset of to-be-attended foreground speech. However, we find alpha power increase with background “white noise” is significantly higher than with background “speech babble” (permutation testing; p-value = 0.003). Topographic maps find alpha power levels and evoked potential amplitudes associated with onset of background sounds are maximal in central and temporal locations. In contrast, topographic maps find the more posterior temporal locations have maximal foreground speech-evoked responses. These findings support a mechanism where both alpha and evoked responses are potential biomarkers of performance on speech-in-noise tasks.

Topic Area: ATTENTION: Auditory