Abstract
PURPOSE: This study investigated the effects of age-related hearing decline on functional networks using resting-state functional magnetic resonance imaging (rs-fMRI). The main objective of the present study was to examine resting-state functional connectivity (RSFC) and graph theory-based network efficiency metrics in 49 adults categorized by age and hearing thresholds to identify the neural mechanisms of age-related hearing decline. METHOD: Forty-nine adults with self-reported normal hearing underwent pure-tone audiometry and rs-fMRI. RSFC within key brain networks and auditory-related brain regions, including the default mode network, salience network, dorsal attention network, and primary auditory cortices, was assessed using region-of-interest-based and graph theory approaches. Functional metrics, such as RSFC strength and global and local efficiency, were compared across age groups (middle age vs. older age) and hearing profile groups (negative screening vs. positive screening and negative high-frequency [HF] screening vs. positive HF screening). RESULTS: Older adults demonstrated significantly weaker RSFC between the left primary auditory cortex and the left rostrolateral prefrontal cortex/anterior cingulate cortex within the salience network than middle-aged adults. Participants without age-related hearing decline exhibited weaker internetwork connectivity within the dorsal attention network and bilateral auditory regions, highlighting the impact of hearing sensitivity on network functionality. Graph theory metrics indicated greater local efficiency in nodes within the salience network among individuals without age-related hearing decline, suggesting preserved cognitive control and attentional processing. CONCLUSIONS: Age and hearing thresholds significantly affected the functional connectivity and network efficiency of the brain. These results emphasize the importance of neuroimaging techniques like rs-fMRI in studying neural mechanisms of age-related hearing loss. SUPPLEMENTAL MATERIAL: https://doi.org/10.23641/asha.29945021.