 - previous treatment with platinum compounds for neuroblastoma, hepatoblastoma, pancreatoblastoma, retinoblastoma, germ cell tumor malignant osteosarcoma, Wilms high risk or relapsed non para-meningeal rhabdomyosarcoma with ototoxicity grade 3 or 4 Brock Grade 3 - 40dB to 2000 Hz; Grade 4-40 dB at 1000 Hz To patients controls 