Distortion Signatures in Later-Life Speech: A Matrix-Based Framework for Separating Aging Variability from Hearing Loss

Later-life communication changes are often attributed to ‘normal aging’ or ‘hearing loss’, yet declines in speech perception, cognitive-linguistic processing, and speech production likely reflect both; this narrative review proposes a matrix-based framework to separate aging-related variability from hearing-loss-specific distortions for interpretable assessment and reporting across clinical and digital settings. Literature (n = 22) was reviewed to summarize age-related changes across key domains, define condition-dependent ‘acceptable variability’ versus repeatable ‘distortion signatures’ in older adults with hearing loss, and integrate these concepts into a unified assessment/reporting scheme that separates audibility/amplification-explained from residual errors after audibility correction. Two matrices were presented. The acceptable variability matrix maps expected age-related changes across domains and testing contexts (quiet clinic, adverse clinic conditions, and remote/automated digital assessment) and specifies interpretation boundaries (“red flags”) for patterns exceeding expected condition-dependent variability. The distortion signature matrix organized hearing-loss– specific patterns into signature modules defined by vulnerable conditions and error profiles, links signatures to audiogram severity/configuration, separates audibility-explained versus residual postcorrection components, and proposed a minimum assessment set for implementable classification and reporting. These matrices were integrated into an assessment/reporting flow supporting screening, out-of-range classification, alignment checks with audiogram and cognitive-linguistic factors, and unified reporting that partitions aging variability versus hearing-loss distortion. This framework is not diagnostic; it standardizes interpretation and reporting to reduce over-attribution and support consistent longitudinal tracking across modalities. Further work should test feasibility, inter-rater reliability, and robustness across tasks and listening conditions, with careful clinical implementation and outcome monitoring.