Event-Related Potentials as Markers of Age-Related Changes of Spatial Hearing in Normal-Hearing Adults

Previous studies have shown that older adults can witness a decline in the integration of their spatial auditory cues even when they don't present pathological audiometric thresholds. Nonetheless, when spatial hearing in aging is discussed, most of the focus concerns elderly individuals with hearing impairments or presbycusis, rather than those with clinically normal hearing. In fact, auditory aging (even without presbycusis) may still result in a decline in spatial sensitivity, potentially contributing to the deterioration of key binaural functions crucial for speech understanding, such as binaural summation, squelch effect, and head shadow effect. The current study aims to determine whether Event-Related Potentials (ERPs) can reflect auditory spatial aging in populations without abnormal audiometric thresholds. Using a spatial oddball paradigm, we aim to explore the neural components associated with spatial sensitivity and examine whether these components correlate with changes in binaural integration with age. Our findings suggested a decrease in spatial auditory performance, speech in noise comprehension, and cognitive status across age even when audiometric thresholds were normal. Electroencephalograhy investigation revealed a strong correlation between N100 amplitudes and age, in addition to correlation between unmasking function and N100 amplitudes. These findings underscore the validity of ERP components as markers of spatial hearing performance and aging. This could orient the decision-making concerning the necessity for hearing rehabilitation in some cases to compensate for deficits and prevent auditory aging consequences on peripheral and central auditory processing.