The Hearing-Cognition Relationship Across the Lifespan: Mechanisms, Interventions and Outcomes

Introduction: Hearing loss and cognitive impairment are among the most common chronic conditions of aging, and a growing body of evidence links the two. The 2020 and 2024 Lancet Commissions identified midlife hearing loss as one of the largest potentially modifiable risk factors for dementia, raising the possibility that auditory rehabilitation could help preserve cognition. Methods: This narrative review provides a lifespan perspective by summarizing current evidence on the relationship between hearing loss and cognitive decline, the cognitive domains most affected, and the mechanisms proposed to explain the association, including the cognitive load, common cause, cascade, and overdiagnosis hypotheses, together with their neurobiological correlates. Results: We then examine the effect of auditory interventions on cognition in adults, considering hearing aids and cochlear implants separately, and discuss landmark trials such as ACHIEVE, which suggest that cognitive benefits may be greatest in older adults at increased risk of decline. Finally, we address the distinct situation of children, in whom early auditory deprivation may shape the development of working memory and executive function and in whom the timely fitting of hearing devices is critical. Conclusions: Overall, the evidence supports hearing loss as a modifiable contributor to cognitive decline and highlights early detection and rehabilitation as promising, though not universally effective, strategies for protecting cognitive health.