The Relationship between Hearing Impairment and Cognitive Function in Middle-Aged and Older Adults: A Meta-Analysis

Objectives: Although many studies have attempted to demonstrate the effect of hearing impairment on cognitive function, findings across studies have been relatively inconsistent. The current study aimed to synthesize the findings of previous cross-sectional studies which compared cognitive performance between middle-aged and older adults with hearing impairment and normal hearing controls. Methods: A systematic literature review was performed using meta-analysis (Comprehensive Meta-Analysis version 3.0). A total of 11 studies meeting the inclusion criteria were included in the current meta-analysis. The effect sizes were obtained by Hedges'g with a 95% confidence interval using a random effect model. Results: Middle-aged and older adults with hearing impairment showed lower cognitive performance as compared to normal hearing controls, especially in the domains of executive function/processing speed, working memory, language, verbal memory, and general cognition. There was no significant difference in visuospatial ability between groups. Also, regardless of whether cognitive measures primarily rely on auditory function or not, hearing-impaired adults showed lower performance than normal hearing controls. Conclusion: The current meta-analytic findings indicate that hearing impairment is associated with cognitive deficits in middle-aged and older adults.