Multisensory assessment for hearing phenotypes

Despite growing evidence of neural and behavioral plasticity following sensory loss, it remains unclear how multisensory processing varies across clinical hearing loss phenotypes. This study investigated visual perception and audiovisual (AV) integration in adults with varying degrees of hearing loss and hearing technology use. Participants included individuals with normal hearing (NH), hearing aid (HA) users, cochlear implant (CI) candidates, and CI users. To assess visual and multisensory processing, we administered a visual temporal order judgment (vTOJ) task, the McGurk illusion, a monosyllabic lipreading task, and an AV word recognition task. Results revealed a trend toward improved visual temporal resolution with increasing hearing loss severity, though this was confounded by age. McGurk illusion responses indicated that the presence of hearing loss decreased auditory weighting, while the severity of hearing loss increased visual weighting. Lipreading performance significantly improved as hearing loss progressed, with CI users outperforming all other groups—possibly due to the use of rehabilitation exercises in the CI clinical protocol. In contrast, AV benefit did not vary systematically with hearing loss, but showed a significant effect of age. Together, these findings suggest that visual performance and visual sensory weighting—more than AV integration per se—are modulated by hearing loss. These differences may reflect underlying plasticity of the cortical regions responsible for processing multisensory input. Furthermore, these findings highlight the potential utility of visual tasks in characterizing sensory phenotypes and informing clinical decision-making for individuals with hearing loss.