When Sound Helps or Hurts: Behavioral and EEG Evidence on the Dual Effects of Indoor Acoustic Environments on Office Work Performance

Prolonged exposure to acoustic environments in office settings may impair employees’ cognitive performance, yet the underlying mechanisms remain contested. This study investigated the dual effects of acoustic intensity and sound type on employees’ performance by integrating behavioral measures, subjective assessments, and neurophysiological evidence. Results demonstrated significant interaction effects: while increasing levels of office noise and music generally impaired accuracy and efficiency, dialog at moderate-to-high intensities (65 dBA and 85 dBA) significantly shortened reaction times compared to the low-intensity condition (45 dBA). Mediation analyses reconciled these patterns by revealing distinct psychological pathways: Tension-Anxiety fully mediated the performance decrement under noise. In contrast, Tension-Anxiety and Anger-Hostility served as partial mediators (29.71%) and suppressors (40.01%) in the relationship between dialog intensity and performance index. Mental workload fully mediated the performance benefits of moderate intensity music. Electroencephalography (EEG) analyses further corroborated the behavioral findings, identifying neurophysiological pathways through which acoustic exposure influenced performance. This study integrated behavioral and neural approaches to provide empirical evidence for optimizing indoor acoustic environments that promote health, comfort, and productivity.