Environmental sounds on office worker performance: Non-invasive monitoring of physiological responses in laboratory settings

Environmental sounds substantially influence occupational health and productivity, particularly in office settings where prolonged background noise exposure coincides with cognitive demands. This study introduces a non-invasive monitoring approach to examine the effects of sound type, intensity, and task difficulty on office workers. A smart cushion was developed to monitor heartbeat and respiration signals, while salivary samples were analyzed for cortisol and glucose. A two-stage controlled experimental protocol was employed. In Stage One, ten participants performed a 2-back working memory task under six standardized sound conditions at 60 dB (LAeq). Based on resulting physiological and performance patterns, these sounds were categorized as positive, neutral, or negative. In Stage Two, thirty new participants were randomly assigned to one of the three soundscape categories and completed four working memory tasks (1-back and 3-back) under two sound intensity levels (40 dB (LAeq) and 80 dB (LAeq)). The results revealed that (1) Different sound types significantly influenced office workers’ comfort perception, task performance, and physiological responses. (2) Higher task difficulty and sound intensity both induced more pronounced physiological responses and reduced performance and comfort. (3) Autonomic measures and cortisol were highly responsive to sound conditions, whereas glucose showed limited sensitivity. This study advances understanding of how environmental sounds shape human health and cognitive functioning in office settings. Evidence from physiological responses provides a robust basis for developing sound management strategies that enhance comfort, well-being, and productivity. These findings support the design of more sustainable and human-centered urban workspaces.