AIMS The study aimed to evaluate longitudinal changes in cochlear implant (CI) outcomes and device usage over time, and to explore the relationship between objective data-logging metrics and patient-reported measures of hearing performance in patients receiving a cochlear implant for single-sided deafness (SSD). METHODOLOGY A retrospective review of the outcomes of 176 CI recipients (108 female; mean age = 54.7 ± 17.7 years; range 18–86 years). Outcome measures included the Speech, Spatial and Qualities of Hearing Scale (SSQ), speech-in-noise performance in three spatial configurations (S0/N0, S0/Nci, Sci/Nhe), and the Tinnitus Reaction Questionnaire (TRQ). Data-logging information reflecting daily device use was also analysed. Linear mixed-effects models were used to assess change over time across the following intervals: Pre-Operative, 3 Months, 6 Months, 12 Months, 24 Months, and Long-Term (≥ 48 months). RESULTS Significant improvements were observed in speech-in-noise perception scores, SSQ and TRQ between pre-operative and all post-operative timepoints (p < 0.05). While formal comparison between manufacturers was not possible due to differences in sample size, differences in variability in outcome were evident. CONCLUSION Cochlear implantation leads to sustained improvements in self-reported hearing ability, speech perception, and tinnitus relief. Consistent device use is a key factor in achieving best possible functional outcomes. These findings underscore the value of long-term monitoring and data-logging to optimise counselling and rehabilitation strategies for CI users.