Hearing Loss, Unilateral

The goal of this clinical trial is to investigate the safety and effectiveness of cochlear implantation in infants and toddlers with single-sided deafness. The main questions it aims to answer are: * Are cochlear implants an effective treatment of single-sided deafness in infants and toddlers? * Are cochlear implants a safe treatment for single-sided deafness in infants and toddlers? Participants will receive a cochlear implant and be followed until they are five years old. During those five years, the investigators will program the device and monitor auditory development. Children will be asked to: * Undergo cochlear implantation * Wear their cochlear implant processor whenever they are awake. * Participate in traditional hearing tests * Participate in traditional hearing testing * Participate in localization testing * Participate in hearing in noise testing * Participate in word recognition testing * Participate in speech, language, and educational evaluations The researchers will compare results to children with typical hearing in both ears and children with single-sided deafness who have not received an implant to observe any differences between the groups.

Children who are deaf or hard-of-hearing (D/HH) are at risk of speech and language delays, which can be mitigated through early identification and intervention. Identifying hearing loss (HL) during preschool is crucial, but the most effective hearing screening method for preschoolers remains uncertain. The purpose of this study is to learn whether, compared to the gold-standard two-stage Pure-tone audiometry (PTA) + otoacoustic emissions (OAE) screening (TS-PO), single-stage OAE (SS-O) screening alone is not inferior at identifying hearing loss when performed in a community-based preschool setting. This study holds the potential to improve early hearing loss detection and intervention among D/HH children, reducing the likelihood of speech and language delays. A diverse group of 13,764 preschool-age children across community-based preschool centers will be recruited. The intervention involves all subjects undergoing both PTA and OAE screening, with the order determined through randomization. Children who show potential hearing issues based on screening results or teacher concerns will receive further testing to determine the final hearing outcome. Group allocation will be post-hoc, based on their screening results. In addition to the primary objective, the study will compare other hearing screening measures and outcomes between the two methods (TS-PO and SS-O). This approach aims to reflect the real-life effectiveness of hearing screening in a diverse population. Ultimately, the study seeks to provide insights into an optimal hearing screening method that could prevent speech and language delays among D/HH children.

The purpose of the study is to evaluate the long-term safety and effectiveness of cochlear implantation of the approved population in adults and children with single-sided deafness and asymmetric hearing loss.

The aim of the study is to assess the continued efficacy and safety of cochlear implantation in participants aged 5 years and above with Unilateral Hearing Loss (UHL)/Single Sided Deafness (SSD) supporting a change indication for use.