A diabetic subgroup identified from a base population who have experienced idiopathic sudden hearing loss (ISHL) has been studied. In order to assess the relationship between diabetes and ISHL, two non-diabetic control groups were formed, and a comparison of the audiological data between the diabetic and non-diabetic ISHL patient was made. Mean degree of hearing loss and recovery, as well as the mean hearing level of the contralateral ear were analyzed. No statistically significant differences were noted in the audiological pattern of ISHL in diabetics and controls. A similar incidence of recovery was noted for the two groups throughout the mid frequencies; however, diabetic ISHL patients fail to recover as well as in the high frequencies. Preliminary data, while not statistically significant, suggest an increased hearing loss in both the affected and unaffected ear of the older diabetic patient.