Speech recognition in noise across the life span with cognition and hearing sensitivity as mediators of age effects

Speech perception in noise relies on both sensory and cognitive systems and is known to decline with age. However, little is known about when this decline begins and how hearing sensitivity and cognition contribute across the lifespan. This study examined 357 Hebrew-speaking participants aged 7-90 years with clinically normal or age-appropriate hearing, using adaptive sentence-in-noise testing alongside measures of auditory working memory and processing speed. Results revealed a U-shaped pattern of speech reception thresholds in noise (SRTn), with peak performance in the late 30s. Polynomial modeling showed that hearing sensitivity (PTA₄) begins to deteriorate around age 17 years, while cognitive abilities declined later-between ages 32-38 years (depending on the task)-coinciding with the inflection point in speech perception. Structural equation modeling (SEM) confirmed that cognitive and auditory factors mediate the relationship between age and SRTn, explaining 61% of the variance. These findings extend the interpretation of the Ease of Language Understanding (ELU) model to a broad age range of clinically normal and age-appropriate hearing individuals and contribute a developmental perspective by demonstrating how age-related changes in cognition reshape speech perception strategies even in the absence of peripheral hearing loss. Implications include the need for cognitive-informed approaches in audiological research and intervention throughout the lifespan.