The influences of low frequency noise on mental performance

Background and Although the evolution of industrial systems toward digital technologies decreased the exposure to high levels of noise, it has created some problems encountered with low level and provoking noise (low frequency noise). In the present work, the mental performance of students exposed to low frequency and reference noises at low and high levels (45 & 65 dB) were studied. Additionally, other factors such as annoyance, sensitivity to low frequency noise and hearing status of participants were considered. After generating low frequency and reference noises required for the study, a pilot study was conducted. Then, 54 students participated in the main study after preliminary tests. Their mental performances were evaluated with standard psychological tests while they were exposed to low frequency and reference noises at 45 and 65 dBA. The results showed that noise annoyance and low frequency noise sensitivity do not have a significant correlation with age and sex. The results also revealed that, low frequency noise at 65 dB can decrease concentration (P=0.003) and increase response time (P=0.039) of performance in comparison with low frequency noise at 45 dB. On the other hand, reference noise at 65 dB can increase speed (P<0.001) of performance in comparison with reference noise at 45 dB. Low frequency noise can reduce the mental performance and increase its response time.