Purpose: The dichotic digits test (DDT) is commonly administered in clinical and research settings, but it is not well understood how performance changes in aging. The purpose of this study is to determine the 5-year change on the free recall task and right ear advantage (REA) in a population-based cohort and factors associated with change. Method: Participants in the population-based Epidemiology of Hearing Loss Study, who completed the DDT during the fourth (2009–2010) and fifth (2013–2016) examination periods were included (n =865,Mage = 72.8 years at baseline). Free recall DDT was administered using 25 sets of triple-digit pairs presented at 70 dB HL. The REA was calculated by subtracting the score in the left ear from the score in the right ear. Results: In 5 years, most participants (62.4%) declined on free recall performance (mean decline = 3.0% [4.5 digits], p < .01). In age-sex–adjusted models, higher baseline scores, hearing impairment, and lower education were significantly associated with increased risk of decline. An REA at baseline (76.8%) and follow-up (77.9%) was common. Half of participants (50.6%) had a 5-year REA widening (M = 1.9% [1.4 digits], p = .01). Older age, but not hearing impairment, was associated with increased risk of REA widening. Conclusions: The 5-year decline on free recall recognition performance was not associated with age but was associated with hearing impairment, whereas the 5-year widening of REA was associated with age but not hearing impairment. These results indicate that the REA may be a more sensitive measure of aging of the central auditory system than free recall performance.
Bibliographical noteFunding Information:
This study was supported by the National Institute on Aging Award R37AG011099 (K. J. C.), the National Eye Institute Grant U10EY06594 (B. E. K. K.), and an unrestricted grant from Research to Prevent Blindness, Inc., to the Department of Ophthalmology and Visual Sciences at the University of Wisconsin–Madison. We would like to acknowledge the contributions of Ronald Klein to this study. He passed away before this article was completed but was a valued member of our investigative group, contributing expertise in epidemiology to the design and conduct of this cohort study.
PubMed: MeSH publication types
- Journal Article