Comparison of behind-the-ear vs. off-the-ear speech processors in cochlear implants: A systematic review and narrative synthesis.

Abstract

BACKGROUND: Cochlear implants (CI) with off-the-ear (OTE) and behind-the-ear (BTE) speech processors differ in user experience and audiological performance, impacting speech perception, comfort, and satisfaction. OBJECTIVES: This systematic review explores audiological outcomes (speech perception in quiet and noise) and non-audiological factors (device handling, comfort, cosmetics, overall satisfaction) of OTE and BTE speech processors in CI recipients. METHODS: We conducted a systematic review following PRISMA-S guidelines, examining Medline, Embase, Cochrane Library, Scopus, and ProQuest Dissertations and Theses. Data encompassed recipient characteristics, processor usage, speech perception, and non-audiological factors. Studies were assessed for quality and risk of bias by using Newcastle-Ottawa Scale (NOS). RESULTS: Nine studies involving 204 CI recipients, with a mean age of 49.01 years and 6.62 years of processor use, were included. Audiological results indicated comparable performance in quiet environments, with a slight preference for OTE in noisy conditions. For non-audiological factors, OTE processors excelled in comfort, handling, and aesthetics, leading to higher satisfaction. More data on medical complications and long-term implications is needed. CONCLUSION: OTE processors may offer comparable performance to BTE processors in certain conditions, though not universally across all audiological outcomes. Interpretation depends on settings, processor generation, and testing paradigms. However, non-audiological factors might favour OTE. Understanding current literature may guide professionals in selecting suitable processors for CI recipients.