Subjective and physiological correlates of semantic information processing with digital noise reduction in hearing aids among older adults with hearing loss

This study investigated how activating digital noise reduction (DNR) in hearing aids affects semantic information processing in older adults with sensorineural hearing loss and explored its relationship with subjective listening experiences and physiological responses. A repeated-measures study was conducted in 36 older adults with mild-to-moderately severe sensorineural hearing loss who used bilateral hearing aids. Participants completed a semantic information processing task under DNR-on and DNR-off conditions. Semantic and phonetic processing scores, subjective ratings of listening effort, fatigue, attention, and concentration, and physiological measures of heart rate and peripheral SpO2 were obtained. Physiological measures were recorded before, during, and after the task.Semantic and phonetic processing scores were significantly higher in the DNR-on condition than in the DNR-off condition (p < 0.001), indicating enhanced speech processing with noise reduction. Subjective ratings indicated reduced listening effort and fatigue, along with improved attention and concentration, while physiological data showed higher oxygen saturation and altered heart rate patterns, suggesting reduced cognitive load with DNR-on. Correlational results showed that reduced effort, as indicated by subjective ratings, was associated with higher scores on semantic processing and higher SpO2 levels. DNR in hearing aids facilitates phonetic and semantic processing, as evidenced by subjective and physiological measures such as SpO2. Yet findings should be interpreted cautiously due to the limitations of pulseOx measurements.