Hypertension is associated with dysfunction of both peripheral and central auditory system

Objectives:Arterial hypertension negatively influences the peripheral auditory system, causing sensorineural hearing loss. Much less is known about the detrimental effects of hypertension on the central auditory functions.Methods:We tested 32 arterial hypertension patients and 32 age and sex-matched healthy volunteers with the expanded tonal audiometry (0.125-12.5kHz), distortion product otoacoustic emissions (0.75-8kHz), horizontal minimum audible angle test for eight azimuths with binaural stimulation and the random gap detection test.Results:Peripheral hearing of the hypertensive patients was impaired in comparison with the controls within all audiometric frequencies (0.125-12.5kHz) and within specific groups of frequencies. Distortion product otoacoustic emission results were significantly lower for frequencies 4 (P=0.04) and 6kHz (P<0.001). The sound localization ability in the horizontal minimum audible angle test was significantly worse in the hypertensive patients in the 0 degrees, 45 degrees, 90 degrees, 135 degrees, and 270 degrees azimuth when the interaural pure tone average (0.5-1-2kHz) was set less than 20dB hearing level (P<0.05), and in the 0 degrees, 90 degrees, 225 degrees, and 270 degrees azimuth when the binaural pure tone average (0.5-1-2kHz) was set 20dB or less hearing level (P<0.05). Gap detection thresholds in the random gap detection test did not differ between the two groups.Conclusion:Arterial hypertension is independently related to the damage of the peripheral part of the auditory system resulting in high-frequency hearing loss. Hypertensive disturbances of central auditory processing are more discrete and concern the spatial hearing resolution.