Bilateral progressive sensorineural hearing loss of unknown etiology

Clinical observations of 28 cases with bilateral idiopathic progressive sensorineural hearing loss (BIPSNHL) were made in comparison with the data from the Research Committee of the ministry of Health and Welfare of Japan. Two types with correlation to the age of onset were found in BIPSNHL; the juvenile type which starts at an early age, and the adult type which is found after maturity. The significance of these two types was discussed. Correct diagnosis is only possible after long-term observations and regular audiometry.