1.4.7 Surgical Procedure: The surgical procedure for the Iowa/Nucleus 10/ 10 mm cochlear implant is different from the Nucleus Freedom cochlear implant. The surgical procedure for the Iowa/Nucleus l 0/10 mm requires care to prevent inner ear damage. The cochleostomy is smaller (approximately 0.5 mm in diameter compares to > 1.0 mm for the Nucleus Freedom electrode). Soft surgery techniques will be used on both. The cochleostomy will be made in a similar position for both devices. Creation of the cochleostomy requires control of bleeding and removal of bone over the scala tympany exposing the endosteum. The endosteum is removed with a .02 mm hook. No suctioning of perilymph is allowed. The devices are then advanced slowly into the cochlea. For the Iowa/Nucleus 10/ 10 mm cochlear implant, the array is inserted 10 mm into the scala tympani and 19 mm for the Nucleus Freedom cochlear implant. Intraoperative impedance telemetry measurements will beperformed using CG,MPJ , MP2 and MP1+2 modes. The postoperative hospital stay is usually <23 hours.