Inclusion Criteria:  CI users with a CII, HiRes90K (Advantage) or HiRes Ultra implant system  Bilateral users: two implant systems Bimodal users: hearing aid contralateral Minimum of 18 years of age Minimum of six months experience with their implant system Minimum of six months experience with the Naída CI Q-Series sound processor Ability to give feedback on sound quality Speech intelligibility with the HSM sentence test in noise at 10 dB SNR > 10% as obtained during previous visits in the clinical routine Fluent in German language  Exclusion Criteria:  Difficulties additional to hearing impairment that would interfere with the study procedures Concurrent participation in other study Pregnant and breast-feeding women