Participants will receive one standard Nucleus Freedom electrode array and an Iowa/Nucleus 10/ 10 mm electrode array on the contralateral side. Half will be implanted with the 10 mm electrode array on their right side and half will be implanted with the 10 mm electrode array on their left side. We will alternate every other subject between the right and left ears. Postoperatively, Iowa/Nucleus 10110 mm electrode alone, standard Freedom electrode alone, and bilateral listening (i.e., Iowa/Nucleus 10/ 10 mm and standard electrodes together) modes will be compared with repeated testing through five years of age of the child. These comparisons will help to evaluate the effects of bilateral stimulation using different cochlear implant devices while possibly preserving the scala media, organ of Corti, and supporting cells for future advances in the ear receiving the Iowa/Nucleus 10/ 10 mm electrode device. In addition, we will attempt to compare these results with age-matched unilaterally implanted children tested on the same speech perception and speech/language measures. In addition, if possible, we will attempt to compare speech perception and speech/language measures on age-matched children with bilateral standard long electrode arrays in both ears. The following defines the various modes referenced throughout the course of this text: