Background: Age-related hearing loss (ARHL) is the most common sensory disorder in older adults and has been identified as a potentially modifiable risk factor for cognitive decline and dementia. Increasing evidence suggests that auditory dysfunction may contribute to adverse cognitive trajectories through multiple interacting pathways. This narrative review examines the mechanisms underlying the association between ARHL and cognitive decline, evaluates the impact of hearing rehabilitation, and discusses future research priorities. Methods: A narrative synthesis of epidemiological, neurobiological, and interventional studies was conducted, with emphasis on longitudinal cohort studies, neuroimaging research, and clinical investigations of hearing aids (HAs) and cochlear implants (CIs). Results: ARHL is consistently associated with accelerated cognitive decline and increased dementia risk. Proposed mechanisms include sensory deprivation-related cortical reorganization, increased cognitive load during effortful listening, shared neuropathological processes, and social disengagement. Neuroimaging studies demonstrate structural and functional alterations in auditory and associative brain regions in individuals with hearing loss. Emerging evidence suggests that HA and CI may improve cognitive performance and potentially attenuate decline, although long-term randomized data remain limited. Conclusions: Current evidence supports ARHL as a clinically relevant and potentially modifiable contributor to cognitive decline. Clarifying causal pathways and optimizing early hearing rehabilitation strategies represent key priorities for future dementia prevention research.
Motta et al. (Tue,) studied this question.