Auditory performance and cortical plasticity in blind individuals with sensorineural hearing loss: insights into dual...

Blind individuals with normal hearing frequently exhibit enhanced auditory abilities driven by compensatory cross-modal neuroplasticity. However, it remains unclear whether these compensatory advantages persist in individuals with dual sensory impairment. This study investigated auditory processing and cortical plasticity in early-blind, late-blind, and sighted individuals, all presenting with concurrent sensorineural hearing loss.

Participants completed auditory behavioral tests, including working memory, spectral ripple discrimination, temporal modulation detection, and sentence recognition in noise. Auditory oddball tasks assessed attentional and cognitive responses, and ERPs (N2, P3b) were recorded.

Results showed that late-blind individuals with hearing loss performed better than sighted individuals in digit span and temporal modulation tasks, but group differences in spectral resolution, speech recognition, and ERP components were largely not evident across conditions. Cortical source and functional connectivity analysis revealed distinct processing strategies, with sighted individuals recruiting frontal control regions under noise, whereas late-blind individuals relied on a temporal-parietal network.

These findings indicate that in late-blind individuals, visual deprivation confers selective advantages over sighted peers in temporal processing and working memory even in the presence of age-related hearing loss, whereas broader perceptual benefits and electrophysiological enhancements are limited. Viewed in the context of prior literature in normal-hearing populations, these results suggest that compensatory cross-modal plasticity may be partially constrained when accompanied by concurrent sensorineural hearing loss.