Cochlear Implant Recipients: Comprehensive Longitudinal Evaluation

Inclusion Criteria: * Patients with severe or greater hearing loss (≥65 dB) scheduled to receive cochlear implant (CI) treatment. * No restrictions on age or gender. * Native language is Mandarin Chinese. * The subject and/or their legal guardian must provide informed consent prior to the study, voluntarily sign a written informed consent form, and be willing to undergo follow-up assessments at the specified time points. * Ability to communicate effectively with the researcher with the help of a guardian and comply with the researcher's requirements. For young children without mature language skills, ability to cooperate with the help of a guardian. * The subject's guardian has a correct understanding of the trial and realistic expectations of potential benefits. Exclusion Criteria: * Presence of other severe diseases unsuitable for cochlear implantation surgery. * Significant psychological problems or mood disorders (e.g., notable anxiety, depression, or behavioral disorders) that would preclude cooperation with training and follow-up. * Neurological diseases (e.g., epilepsy, cerebral palsy) that may affect auditory processing ability. * Concurrent participation in other interventional studies involving drugs or behavioral interventions that may affect auditory rehabilitation during the study period. * Any other condition considered by the investigator to make the subject unsuitable for participation in this clinical study.