During middle ear surgery, surgeons often felt if they could assess hearing changes after ossicular reconstructionprocedure under general anesthesia. Twenty-four ears with tympanosclerosis, otosclerosis, dislocationof the ossicles due to head injury, middle-ear malformation and cholesteatoma were monitored with electrocochleography (ECochG) during surgery. Seventeen showed significant enlargement of AP amplitude toa 85dB click stimulus after the ossicular reconstruction, and the postoperative hearing in 16 of them wasfound improved with an average of 15dB or more. In 7 patients who underwent the surgery early in thisstudy, clear ECochG recordings could not be obtained because the hearing in high-frequency tones was worsethan 70dB in 4 and high electrode resistance was observed due to the unstable ball electrode in the remaining3. Two of the 7 patients showed postoperative hearing improvement. We believed that intraope-rativeECochG with needle electrode enabled surgeons to assess the hearing improvement objectively after theossicular reconstruction.
