Neuroendocrine and cardiometabolic responses to acute traffic noise and natural-sound masking in healthy adults: a randomized crossover trial

Abstract Background : With urbanization accelerating, traffic noise has become a significant environmental factor in daily urban life. Objective : This study investigates the effects of short-term traffic-noise exposure on energy metabolism and physiological status in healthy individuals, systematically characterizing the metabolic pathways induced by noise and exploring the protective role of mask sound (natural mixed sound) intervention. Methods : A randomized crossover design was employed, with 26 healthy adults exposed to three types of sound environments: quiet (46.52 dBA (± 0.31), 8:00 AM - 7:00 AM the next day), traffic noise (76.23 dBA (± 1.21), 8:00 AM - 10:00 PM), and mask sound (76.15 dBA (± 1.32), 8:00 AM - 10:00 PM). Continuous monitoring tracked energy metabolism, physiological indicators, hormone levels, and subjective feelings, with comparisons across environments. Results : Short-term traffic noise amplified sympathetic, HPA, and HPT axis activity, raising heart rate and blood pressure (HR +2.95%, diastolic BP +3.09%). Glycemic regulation worsened (glucose up 7.72%), metabolic flexibility declined (ΔNPRQ postprandial − fasting −42.11%), and rhythms/mood were disrupted. Women exhibited more pronounced autonomic and metabolic disturbances. Mask sound modestly mitigated adverse effects, improving cardiovascular measures (HR +2.55% decline, diastolic BP +0.3%), lowering insulin resistance (glucose down 4.39%), and enhancing metabolic flexibility (ΔNPRQ postprandial–fasting +41.67%), though protection was weaker in women. Conclusions : We concluded that short-term traffic noise triggers broad neuroendocrine activation and may elevate the risk of cardiovascular and metabolic diseases, particularly in women. Mask sound intervention effectively attenuates acute metabolic and physiological damage, suggesting potential nonpharmacological benefits for noise protection. Trial registration : ChiCTR2500098645