The purpose of this study is to evaluate whether the Iowa/Nucleus 10/10 mm in one ear, in conjunction with a Nucleus Freedom implant in the other ear can provide useful binaural hearing in pediatric subjects who have bilateral severe to profound hearing loss and meet the criteria for cochlear implantation. The Iowa/Nucleus 10/10 mm cochlear implant has a short, 10 mm electrode array that it is inserted only into the more basal region of the cochlea. Unlike a conventional cochlear implant, the Iowa/Nucleus 10/10 mm is expected to preserve the regions of the cochlear partition that are apical to the electrode, thus leaving them available for possible future advances in the field of otolaryngology and hearing devices, such as mammalian hair cell regeneration techniques or improved implantable hearing devices. The Iowa/Nucleus 10/10 mm will be implanted in the contralateral ear from the Nucleus Freedom electrode array as a means of providing bilateral stimulation of auditory pathways while preserving the middle and apical regions of the scala media.

• Hearing Loss, Sensorineural
• Hearing Loss, Bilateral

Inclusion Criteria:

• Twelve to twenty-four months of age at the time of implantation.
• Audiometric thresholds for frequencies 250 to 8000 Hz in the severe-to-profound hearing range bilaterally. The type of hearing loss must be categorized as sensorineural in nature.
• English spoken as a primary language (mono-lingual English speaking family, where English is the primary language).
• Willingness to comply with all study requirements.
• Multiple visits may be necessary preoperatively and/or postoperatively for data collection due to age and attention.
• Minimum of three month hearing aid trial.
• Patent cochlea and normal cochlear anatomy as shown by a CT Scan. It is standard clinical practice to perform a CT Scan on any patient pursuing cochlear implantation.
• Must be in a habilitation/educational program with an emphasis on spoken language development.

Exclusion Criteria:

• Medical or psychological conditions that contraindicate undergoing surgery.
• Ossification or any other cochlear anomaly that might prevent complete insertion of the electrode array.
• Developmental disabilities or other conditions that would prevent or restrict participation in the audiological evaluations and clinical trial.
• Hearing loss of neural or central origin.
• Unrealistic expectations on the part of the candidate and/or candidate's family,regarding the possible benefits, risks, and limitations that are inherent to the surgical procedure(s) and prosthetic devices.
• Unwillingness or inability of the candidate to comply with all investigational requirements.
• Active middle ear infection.