Behavioral Discrepancy of P300 and Cognitive Load in Varying Auditory Speech Perception

People with hearing loss find it challenging to process complex speech signals and yet mislead speech perception. The relationship between P300 evoked response and cognitive load from electroencephalography (EEG) frequency bandwidth could inform speech perception discrepancy. This study aims to investigate functional relationship of P3b behavioral response and cortical neuronal oscillations of cognitive load activity at different phonological features of speech stimulus. Two groups of participants were recruited: ten male adults having bilateral sensorineural hearing loss (SNHL) and ten male adults with normal hearing. They underwent EEG recording while delivered with two distinctive speech stimuli namely voicing contrast and placing contrast at 80 dB. The P3b evoked potential and cortical oscillatory activities were measured throughout the targeted potential window. Statistically significant differences between speech stimulus amplitude responses were noted in the control participants, especially on
${C}_{z}$
and
${P}_{z}$
. In the control group (CG), placing contrast showed higher amplitudes and delayed latency compared to voicing contrast. The patient group (PG) had lower P3b amplitudes and earlier latency at similar conditions. Greater power energy was deployed at alpha and theta activities for the control participants at placing contrast. Higher complexity discriminant was evident in placing contrast when delayed latency with higher energy power for alpha and theta activities were constantly observed. The peak P3b highlighted the functional relationship with cognitive load response when evaluated at different hearing capabilities. The diminished power levels in higher complexity discriminant have brought an objective understanding of the loss of attention and perception task withdrawal during higher order processing among disability.