Diabetes mellitus is characterized by metabolic abnormalities with longterm complications involving the multiorgan system. Some disagreement exist whether diabetes mellitus can cause hearing loss. An audiological study was performed in 100 patients with diabetes mellitus in order to establish whether there was a relationship among duration of disease, complication, fasting blood sugar and glycosylated hemoglobin. The results were as follows : 1) The incidence of hearing loss of the diabetic patients in high frequency(4-8KHz) was 68%. 2) The duration of disease, FBS and complications did not correspond to the SNHL. 3) When the incidence of hearing impairment was compared with HbA1c, there was significant difference between those under and over 10%(p<0.05). In our conclusion, changes of hearing are reversible, and clinically the patient may improve with metabolic control.