Study on the hearing impairment in diabetic patients

In order to accurately evaluate the quality and quantity of hearing loss in diabetics and to identify the site of the lesions, Békésy audiometry, impedance audiometry with stapedius reflex test, speech discrimination and electrocochleography and brainstem auditory evoked potentials were performed in 43 patients with diabetes mellitus. The results were compared with those of 43 sex- and age-matched non-diabetic subjects. The results showed that the average acoustic thresholds and AP reactive thresholds were significantly elevated in diabetic subjects as compared with those in the controls. There was a significant decrease in mean PBmax% in the diabetic group. The incidence (48%) of hearing impairment in diabetics is higher than that (10%) in controls. The diabetic hearing impairment is characterized by bilaterally symmetrical high tone sensorineural deafness.