Background <p>Psychoacoustic abilities play a significant role in speech perception, especially in noise and other abilities such as music perception and cognition. This systematic review intends to understand the psychoacoustic abilities of post-lingually hearing-impaired cochlear implant (CI) users.</p> Methods <p>An extensive systematic literature search in the following databases and search engines—PubMed, Google Scholar, ComDisDome (ProQuest), and ScienceDirect, was conducted. Only articles published between 2004 and 2024 that examine the various psychoacoustic abilities of post-lingually hearing-impaired adult CI users were reviewed. A PRISMA statement was followed for the systematic search, and Rayyan software was used to compile and screen articles. The National Institute of Health (NIH) quality assessment tool for observational cohort studies was used for the quality assessment.</p> Results <p>Out of 13,664 articles, 13 were selected for the review following a thorough screening of titles, abstracts, and full-length articles. These selected studies collectively evaluated the performance of 212 participants. The articles with a quality rating of fair to good were included in the study. In the 13 studies, researchers investigated temporal processing abilities, spectral abilities, intensity, and frequency discrimination abilities.</p> Conclusion <p>Some studies included in the review had small sample sizes. Significant variations were observed in temporal processing performance and spectral abilities among CI users. Overall, CI users demonstrated poorer results across all tests discussed in the studies, with some tests showing statistically significant differences. Multiple subject-related and device-related factors influence these outcomes.</p>