Ambulatory autonomic nervous system activity in relation to hearing impairment

Previous research has demonstrated that hearing impairment is associated with heightened subjective experiences of listening effort, fatigue, and stress, impacting daily functioning. This study aimed to evaluate whether hearing impairment alters physiological stress systems and whether different aspects of hearing impairment could vary in predicting dysregulation in these systems. Hallmark measures of parasympathetic and sympathetic nervous system activity were derived from electrocardiography, impedance cardiography, and electrodermal activity recordings taken from 133 individuals, aged 37 to 73, over two 24-hr periods, including sleep. Using ecological momentary assessment (EMA), participants reported mood, listening effort, and fatigue seven times daily. Hearing impairment was quantified through pure tone thresholds, speech perception in noise testing, and the Amsterdam Inventory for Auditory Disability questionnaire (Amsterdam Inventory). Using mixed models, we compared average daytime and sleep values of physiological measures across the 2 days, and their daytime-to-sleep contrast, based on each hearing impairment assessment. Results indicated that all three hearing impairment assessments were strong predictors of EMA outcomes of listening effort and fatigue. Contrary to expectations, hearing impairment did not have a significant impact on parasympathetic activity in daily life or on skin sympathetic activity. However, individuals with higher impairment exhibited a larger change in a cardiac sympathetic measure, the pre-ejection period, during wakefulness compared to sleep. Overall, hearing impairment had a small impact on autonomic nervous system functioning in daily life, but the effects were potentially attenuated by reduced exposure to listening demand in those with hearing impairment.