In the hospital for pulmonary tuberculosis in children, a group of 975 children treated with streptomycin sulphate was audiologically examined and in 36% of children ototoxic lesions were defined. From these, in 24% the damage affected only the vestibular labyrinth, in 8% both the vestibular labyrinth and the organ of Corti and in 4% the organ of Corti alone