Association between phonological processing skills and cochlear implant outcomes in adults with acquired hearing...

The objective was to examine the relationship between phonological processing skills and speech recognition outcomes after cochlear implantation in adults with acquired hearing loss, using both pre- and post-implantation measures.

A systematic review was conducted in accordance with PRISMA guidelines. MEDLINE, CINAHL, and EMBASE databases were searched for studies investigating phonological processing and cochlear implantation. Two reviewers independently screened studies according to predefined PICOST criteria. Eligible studies included randomized and non-randomized (cross-sectional or longitudinal) studies published in English or French between 1998 and 2024, involving adults (≥18 years) with acquired hearing loss who received at least a cochlear implant. Studies were required to assess phonological processing before and/or after implantation and report speech recognition outcomes. Methodological quality was also evaluated.

Of 1649 records identified, 26 full-text articles were screened, and 9 studies met the inclusion criteria. Extracted data included study design, participant characteristics, hearing loss history, implant use duration, assessment methods, and performance on phonological, speech recognition outcomes, and cognitive measures. The available evidence was limited and highly heterogeneous in terms of study design, assessment tools, and outcome measures. Quality assessment revealed predominantly low-to-moderate levels of evidence, reflecting methodological limitations.

Current evidence is low to support the hypothesis that stronger pre-implantation phonological processing skills predict speech recognition outcomes after cochlear implantation. Further studies using standardized assessments and more robust methodologies are needed to clarify the role of phonological processing in cochlear implant outcomes.