Relationships Among Hearing, Auditory Processing, and Cognition: A Study of Older Adults.

Background/Objectives: Beginning in mid-life, age-related cognitive decline may negatively affect overall hearing health. Thus, understanding the relationship between hearing and cognition is of critical importance. Although the relationship has received considerable attention, and numerous theories have been posited to explain it, questions remain. Research indicates that 50% of older Americans grapple with severe hearing loss, affecting their daily communication, while Alzheimer's disease, a prevailing cause of dementia, affects approximately 11% of Americans aged 65 or older. The Lancet Commission underscores hearing loss as a leading modifiable risk factor for dementia, contributing up to 7% of the risk. The purpose of this study was to advance our understanding of the specific domains of hearing and cognition that are related, thus informing theory and clinical practice. Methods: Participants were 99 older adults (mean age = 73 years) recruited from the 10-year Indicators of Cognitive Change study. Measures of peripheral hearing sensitivity (four-frequency pure-tone average [PTA4]) and auditory processing (Dichotic Sentence Identification [DSI]) were used to predict performance on multiple measures from the Montreal Cognitive Assessment (MoCA) and Cogstate Brief Battery (CBB). Results: DSI emerged as a significant predictor across both MoCA and CBB, surpassing the predictive power of PTA4. Surprisingly, relationships between hearing and cognitive measures differed for MoCA domains versus CBB subtests, highlighting the complexity of this association. Conclusions: The ability to separate and identify competing auditory information may be necessary components of healthy cognitive function. In clinical practice, assessment of binaural auditory processing may provide an early indicator of cognitive vulnerability in older adults.