Distinct Roles of Working Memory and Inhibitory Control in Speech-in-Noise Perception.

Difficulty perceiving speech in noise is the primary complaint of patients seeking hearing healthcare, even absent overt losses in audiometric thresholds. Yet current clinical practice largely focuses on sensory function while ignoring the potentially outsized effects of executive function on everyday suprathreshold listening. Speech perception in noise depends on the dynamic interplay between the fidelity of sensory coding along the auditory pathway and higher-order top-down cognitive processes that support goal-directed listening, both of which can independently change across the lifespan. Here we examined how two subcomponents of executive function, working memory and inhibitory control, vary across the adult lifespan and contribute to speech-in-noise performance. Two hundred participants aged 18 to 73 with normal hearing thresholds were tested on a validated online auditory psychophysics platform. Working memory was assessed with an n-back task and inhibitory control with an auditory Stroop task. Participants then performed two speech-in-noise tasks: a modified rhyme test emphasizing sensory coding through energetic masking at the cochlea, and a matrix sentence task emphasizing executive function through informational masking. Age significantly affected performance on both tasks. Aging was associated with reduced inhibitory control (increased Stroop cost) but no significant effect on working memory. Regression analyses revealed that both working memory and inhibitory control predicted performance on the informational masking task, whereas only inhibitory control predicted performance on the energetic masking task. These findings underscore the critical role of executive function in everyday suprathreshold listening and support including cognitive measures in clinical assessments of hearing difficulties.