Study of the physiological and mental health effects caused by exposure to low-frequency noise in a simulated control room

The purpose of this study was to investigate the physiological and mental health effects caused by exposure to low-frequency noise in typical control rooms and office-like areas. The participants were 35 male students who were exposed to noise at levels of 55, 65, 70, and 75 dBA. The N-back test was used at three cognitive performance loads (low workload (n = 1), medium workload (n = 2), and high workload (n = 3) to evaluate working memory simultaneously in an air conditioning chamber in four sessions with a constant level. The electroencephalography, electrocardiogram, and electrooculography were measured using Nexus 4 by Bio traces software (Mind Media Co.). For evaluation of mental fatigue, fatigue visual analog scale, and psycho-physiological indices were also used. The results showed that the losses of physiological and mental health were rapidly increased with exposure to noise levels of 65–75 dBA. The results showed that mental fatigue significantly affected heart rate, low- to high-frequency ratios, and electroencephalogram indices such as theta, alpha, as well as eye activities and working memory. The findings confirmed that the mental fatigue caused by low-frequency noise significantly impacted the employees’ psycho-physiological and working memory responses. Implementation of the effective interventions to overcome employees’ mental fatigue in typical control rooms and office-like areas can improve the health and acoustic comfort and, consequently, the cognitive performance.