Breaking down the ear-brain dichotomy: the effects of age-related hearing loss on the cortical language system

Older individuals frequently experience hearing difficulties, often due to sensorineural hearing loss (HL) primarily originating in the inner ear. However, it is not uncommon for older adults with HL to also exhibit impairments in speech intelligibility and comprehension, and seemingly paradoxically, similar circumstances are often observed in older adults without observable hearing pathology. In this review article, we address the fallacy of a strict ear-brain dichotomy in the context of HL and provide empirical evidence that a one-sided perspective that posits that speech processing deficits are moderated exclusively by dysfunctional peripheral ear functions and potential cognitive decline does not satisfactorily explain the phenomenon. We argue why such a dichotomy is conceptually problematic, how it misrepresents the role of the cortical language system and emphasizes how HL impacts neural networks supporting language functions structurally and functionally. We also discuss possible compensatory interventions that help maintain the integrity of speech comprehension and outline possible avenues for future research in this area.