Purpose :Some oldest patients rehabilitated with a cochlear implant more than 20 years ago could still be upgraded with new generations of speech processor (SP). The aim of this study was to show the benefit of a recent generation of SP in this population. Methods : A monocentric prospective study was designed to evaluate the performance of 33 ancient CI22M users implanted between 1989 and 1997 and upgraded with the late compatible sound processor CP900. Performance was evaluated in quiet and noise with Framatix, an automated adaptative test. Results : Performance using Framatix significantly improved with the CP900, with a decrease of the median speech perception threshold of 6 dB in quiet (p < 0.05) and 5,3 dB in noise (p < 0.0005). No subjective benefit using the APHAB questionnaire was observed. Conclusion : Upgrading of cochlear implant recipients who were implanted more than 20 years ago with recent compatible and new technological SP provide benefit in speech recognition in noise.