Figure 5. Drawings illustrate surgical technique. In A, a skin flap incision is made behind the ear. In B, after an intact canal wall mastoidectomy is performed, the facial recess is opened. A cochleostomy is then created by drilling anteriorly (arrow) from the round window into the basal turn of the cochlea. A = antrum, C = chorda tympani, F = facial nerve, HSC = horizontal semicircular canal, I = incus, R = round window, S = stapes. In C, an electrode array is placed (arrow) in the cochlea with an introducer.