Twenty two channel cochlear implant(Nucleus type) was implanted in two totally deaf Korean patients(43-year-old house wife, and 30-year-old male farmer). Both of these cases needed fine drilling of the obliterated basal turn of the cochlea which made it possible to introduce all of the active electrodes into the cochlea. The formant-based speech processing strategy of F₀/F₁/F₂ mode was used. The dynamic ranges were more than 40 over all of the active electrodes of each patient. The scores of vowel and consonant confusion test reached up to 100% and 93% respectively in the first case, and 94% and 75% respectively in the second case with lip reading and speech processor. It seems to be better to use cochlear implant in recently deafened patients with good lip reading and preserved speech(first patient) than in long time deaf without any memory of environmental sound at all(second patient). Further experiences will give better results to the patients for cochlear implantation.