Auditory Processing but Not Peripheral Hearing Differs Between Older Adults With and Without Mild Cognitive Impairment.

Purpose: Impairments of hearing and auditory processing (AP) have been indicated as risk factors for dementia, but it remains unclear if persons with clinically diagnosed mild cognitive impairment (MCI) show such impairments. The objective of these analyses was to compare AP between those with and without a clinical diagnosis of MCI using a battery of AP measures.

Method: Data from 274 older adults from the Keys to Staying Sharp randomized clinical trial (NCT03528486) were analyzed. A battery of AP measures in which three domains (temporal processing, binaural processing, and degraded speech understanding) were addressed by six tests was administered. Analyses were registered at https://osf.io/nga4v.

Results: Those with and without a clinical diagnosis of MCI differed significantly in age, p = .002; pure-tone hearing in the left ear, p = .007; sex, p = .015; and race, p < .001. These covariates were included in multivariate analysis of covariance, which indicated significant differences between persons with and without MCI on measures of binaural processing (ps ≤ .006), but not on measures of temporal processing or degraded speech (ps ≥ .093). Pure-tone hearing averages did not significantly differ among those with or without MCI after adjusting for age, sex, and race (ps ≥ .292).

Conclusions: AP in the binaural domain is impaired in MCI, but peripheral hearing did not significantly differ between those with and without MCI. Poor performance on AP measures of binaural processing may reflect problems dividing attention and may be indicative of dementia risk. Results have clinical implications for early detection of and intervention for cognitive impairment.