Original research paper Conversion of adult Nucleus ® 5 cochlear implant users to the Nucleus ® 6 system

Objectives: Cochlear’s new sound processor system (Nucleus ® 6) features a new noise reduction algorithm called SNR-NR (signal-to-noise ratio), and an environmental classifier called SCAN, which activates the appropriate sound coding algorithms for a given listening environment. In addition, the sound processors (CP910 and CP920) have a data logging feature with data visually summarized using clinical programing software and come with two remote controls, CR210 and CR230. The objective of this clinical study was to conduct a field acceptance study comparing the user experience with the Nucleus ® 6 to the Nucleus ® 5 system and to evaluate the benefits of Nucleus ® 6 in an adult population currently equipped with the previous generation Nucleus ® 5 sound processor. Our primary objective was to compare speech recognition in speech-weighted noise using Nucleus ® 6 with SCAN (activating SNR-NR) with the default Nucleus ® 5 ‘Noise’ Program. Secondary objectives included comparisons of speech recognition in quiet, subjective performance feedback via questionnaires and diaries, and recipient preference for device and program type. Methods: A prospective controlled trial was conducted with 30 adult Nucleus CI recipients using the Nucleus ® 5 sound processor (condition A). The Nucleus ® 6 sound processor (condition B) was evaluated in a within-subject ABBA design, with repeated speech in noise (S0N0, LIST sentence test), and speech in quiet testing (S0, NVA words). The remote controls were randomly given during the two B intervals. In addition, recipients had to complete questionnaires and diaries on the use of their current as well as new sound processors and remotes. Results: The group mean speech reception threshold in noise (SRT50) with Nucleus ® 6S CAN was significantly better (1.2 dB SNR) than with the Nucleus ® 5 ‘Noise’ Program. Mean speech recognition scores in quiet were not significantly different between the processors. Subjective performance feedback (APHAB) did not show a significant difference between Nucleus ® 6 and Nucleus ® 5 with high satisfaction scores being reported for both sound processors. Recipients preferred the SCAN program in noise and reported a clear overall preference for the Nucleus ® 6 system. Clinicians were satisfied with the conversion process from Nucleus ® 5 to Nucleus ® 6. Discussion and conclusion: SNR-NR provides a significant benefit in noise. Recipients were easily converted from Nucleus ® 5 to Nucleus ® 6 requiring little or no sound quality adjustment period. The Nucleus ® 6S CAN program was well accepted by the majority of recipients for use during their daily life.