The Influence of Cognitive Load on Acoustic Reflex Thresholds in Normal-Hearing Young Adults

Abstract

Objective: To investigate whether cognitive load (CL) influences the acoustic reflex thresholds (ARTs) in normal-hearing adults, and whether task type and individual differences in inhibition control modulate these effects.

Design: A within-subject, repeated-measures design was employed. ARTs were measured under four conditions: baseline (no task), visual distraction (VD), two-back image, and two-back rhyme. The order of the two-back tasks was counterbalanced. Repeated-measures ANOVA with planned contrasts and Bonferroni-adjusted post-hoc comparisons were used to analyse ARTs. Exploratory analyses examined associations with gender, baseline performance, and inhibition control measured by the Stroop effect.

Study Sample: Twenty-nine adults (21 females, 8 males; mean age = 24.9 years, SD = 2.1) with normal hearing participated.

Results: Mean ARTs increased from baseline (72.7 dB HL) to VD (75.4 dB HL), two-back image (75.4 dB HL), and two-back rhyme (76.6 dB HL). Only the two-back rhyme condition was significantly elevated compared with baseline (p = .003). Gender was not a significant predictor. Baseline ARTs positively correlated with task thresholds (r = .44-.51). Stroop performance was not associated with ART modulations.

Conclusion: ARTs were modulated only under the two-back rhyme task, indicating that the high cognitive demands of this condition led to threshold elevation.