Evaluation of the Efficacy and Safety of the Sullivan Cochlear Implant.

Inclusion Criteria: * Patients with sensorineural hearing loss of 1 side or both sides (70 dBHL) or higher, aged 19 years or older * No previous cochlear implantation history in the ear scheduled for surgery * No contraindications to surgery, such as cochlear agenesis or auditory nerve agenesis, as determined by imaging tests * Patients without cancer, autoimmune disease, or neurological disease * Patients with a general condition that allows general anesthesia * Patients with no abnormalities in personality, depression, anxiety, sociality, or problem drinking tests * Use Korean * Patients who agree to participate in the clinical trial and sign a written consent form However, if the patient is unable to sign, the patient (if able to sign) and guardian (or agent) voluntarily agree to participate in the clinical trial and sign an informed consent form Exclusion Criteria: * Cases where electrode insertion is difficult due to severe internal malformation, cochlear ossification, etc. * Cases with cancer or autoimmune disease * Cases with a general condition that makes it difficult to tolerate general anesthesia * Cases with moderate or higher mental disability or where auditory training is difficult due to the absence of parents or supporters to assist with rehabilitation education * Cases deemed inappropriate for this test by the clinical trial manager