Background: Patient-reported outcome measures (PROMs) are important tools in adult hearing healthcare to assess hearing-related disability, psychosocial impact, and effectiveness of hearing rehabilitation. However, substantial variability exists in the psychometric quality, depth of validation, and clinical interpretability of commonly used PROMs. The 2025 National Academies of Sciences, Engineering, and Medicine (NASEM) consensus report, Measuring Meaningful Outcomes for Adult Hearing Health Interventions (National Academies of Sciences & Medicine, 2025), highlights a gap between recommended outcome domains and the strength of the psychometric evidence supporting commonly used PROMs. In particular, limited evidence exists regarding responsiveness, minimal clinically important differences (MCID), and interpretability, constraining meaningful outcome comparisons and guideline development. To date, no review has systematically evaluated these PROMs using standardized frameworks such as COSMIN (COnsensus-based Standards for the selection of health Measurement INstruments). This systematic review aims to provide a structured, COSMIN-based evaluation of PROMs assessing hearing disability, hearing aid benefit, and satisfaction, aligned with internationally defined outcome domains. This review focuses on self-report instruments identified in the NASEM report to ensure policy-relevant alignment. Methods: This systematic review follows PRISMA 2020 guidelines and COSMIN standards. Databases (PubMed, Scopus, Web of Science, CINAHL, PsycINFO) were searched from inception to 24 February 2026. Eligible studies include original instrument development, validation, and psychometric evaluation of 1 IHCON 2026 PROMs identified in the NASEM report assessing hearing-related psychosocial health, speech communication, and sound localisation in adults (≥18 years). Measurement properties assessed include content validity, structural validity, internal consistency, reliability, measurement error, construct and criterion validity, responsiveness, and interpretability. Two reviewers independently conduct screening, data extraction, and methodological quality appraisal using the COSMIN Risk of Bias checklist. Evidence will be synthesised narratively and graded using a COSMIN-adapted GRADE approach. Supplementary search strategies, including reference screening and AI-assisted approaches, are also being employed. Results: The database search yielded 960 records after duplicate removal, with 100 studies included for full-text screening. An additional 11 records were identified through AI-assisted supplementary searches (NotebookLM and Claude AI), of which seven were included for full-text review. Full-text screening and data extraction are ongoing. Conclusions: This review will provide a comprehensive COSMIN-based evaluation of PROMs recommended within the NASEM framework and identify key gaps in psychometric evidence. Findings will support the selection of robust outcome measures and contribute to the development of standardised, evidence-based outcome frameworks in adult hearing healthcare.