OBJECTIVES: A cochlear implantation (CI) system consists of a cochlear implant and an external sound processor (SP) which work together to address sensorineural hearing loss. In recent years, a series of innovations have been introduced to the SPs that resulted in the development of Nucleus 5 and 6 (N5; N6). The primary design goal of these SPs was to improve hearing performance in a range of difficult listening environments. The aim of this literature review was to evaluate the evidence of the clinical benefits of these new generations of SPs compared with the older generations among the patients with cochlear implants.

METHODS: A literature search was conducted using PUBMED from the period of 1 January 2010 to 1 March 2018. The search terms used were cochlear implantation, sound processor, Nucleus 5 and Nucleus 6. All study types except opinion and review articles were included. The search was limited to the studies on humans and in the English language. The primary endpoints of interest were speech perception tests in noise and in quiet. An initial review was performed based on title and abstract. Relevant studies were included for full review.

RESULTS: The search initially identified nine citations, six of which were considered relevant and included for full review. Three additional studies were identified through manual search. A total of 339 patients across nine studies were reviewed. 3 studies assessed the clinical benefits of upgrading to N5 and the remaining 6 studies assessed the clinical benefits of N6. All of the studies showed statistically significant improvement in mean score for speech perception in noise. For speech perception in quiet, N6 and N5 were at least equivalent to the older generations.

CONCLUSIONS: There was evidence of clinical benefits in those who upgraded to N5 and N6, particularly in a noisy environment.