Background: Cochlear implantation is an effective intervention for children with single-sided deafness (SSD) because it improves speech perception, sound localization, and listening effort. Current U.S. Food and Drug Administration (FDA) approval limits implantation to children 5years of age and older; however, early intervention may better align with sensitive periods of binaural auditory development. Purpose: To evaluate auditory outcomes of children with SSD who underwent cochlear implantation before the FDA-approved age of 5years and those of children with SSD who underwent cochlear implantation after this age to determine whether early off-label implantation confers auditory advantages. Research Design: This retrospective analysis examined auditory outcomes using linear mixed-effects models for repeated measures. Study Sample: Data of 131 pediatric cochlear implant recipients with SSD were analyzed (Under group: n 60; Over group: n 71). Participants underwent cochlear implantation at a single center prior to age 11years and had at least one follow-up datapoint. Data Collection and Analysis: Dependent variables included daily device use (hearing hours percentage HHP), word recognition (consonant-nucleus-consonant CNC test), speech-in-noise (SIN) performance (Bamford-Kowal-Bench BKB-SIN), and localization accuracy. Predictors included age group (Over vs. Under 5years), chronological age at testing, time since activation, and newborn hearing screening (NBHS) status. Random intercepts accounted for within-subject variability. Results: Most children in the Under group (83 percent) were identified via the NBHS status, whereas much of the Over group (56 percent) passed the screening. The HHP decreased with age in the Over group, but it remained stable in the Under group. Although children in both groups still typically used their cochlear implants (CIs) at age 10years and older, the Under group used their CIs for a greater proportion of the day. A significant decrease in HHP occurred over time since activation. The CNC outcomes showed significantly steeper gains in speech recognition among younger recipients and those with higher HHPs. For BKB-SIN, age and test condition were significant, thus confirming spatial release from masking across groups. Localization accuracy significantly improved with longer CI experience and more frequent device use, with a marginal group effect favoring early implantation. Conclusions: Although cochlear implantation before age 5years remains off-label, those who underwent early cochlear implantation demonstrated more stable device use, faster speech recognition gains, and trends toward better spatial hearing. Therefore, earlier implantation may be advantageous. Clinical Relevance Statement: These findings support the consideration of developmentally informed candidacy for CIs among children with SSD and suggest potential benefits of cochlear implantation before age 5years.
Park et al. (Thu,) studied this question.