Purpose: To determine if sleep apnea had significant effects on hearing functions and to investigate the polysomnography parameters that might be associated with hearing impairment in sleep apnea patients.
Methods: We included 120 patients who were admitted to sleep disorders outpatient clinic. We constituted four groups by reference to the apnea-hypopnea index (including control group), and compared the audiometric parameters of the groups. Additionally, we investigated the correlation of apnea-hypopnea index, desaturation index and min. oxygen saturations with pure-tone thresholds, speech recognition thresholds and speech discrimination scores.
Results: The median pure-tone thresholds at 250, 500, 1000, 2000, 4000 and 8000 mHz, the median speech recognition thresholds and the median speech discrimination scores on both ears did significantly differ among four groups (p < 0.001). Moderate sleep apnea affected high-frequency hearing functions and speech discrimination scores, and severe sleep apnea had significant effects on all hearing functions. Pure-tone thresholds and speech recognition thresholds on the both ears were positively correlated with apnea-hypopnea index and desaturation index, and negatively correlated with min. oxygen saturation (p < 0.001). Speech discrimination scores on the both ears were negatively correlated with apnea-hypopnea index and desaturation index, and positively correlated with min. oxygen saturation (p < 0.001).
Conclusion: Obstructive sleep apnea syndrome (OSA) had several effects on hearing, and hearing impairment might be associated with the severity of OSA. Moderate OSA affected high-frequency hearing functions and severe OSA affected all hearing functions negatively.
Keywords: Audiometry; Hearing; Polysomnography; Sleep apnea.