Changes of alpha and beta brain waves in exposure to different levels of noise

Noise is one of the most important environmental stressors, which, along with the prevalence of exposure in the work and living environment, has various effects. Noise exposure can create positive or negative consequences at different levels. Based on this, in the present study, brain wave changes in exposure to different levels of noise were investigated. In this experimental study, 72 student volunteers with an average age of 26.27 years old, participated in this study after meeting the exclusion criteria and receiving sufficient training regarding the implementation procedure. Before starting the test, demographic questionnaires, noise sensitivity, and audiometry were completed for the participants. For exposure, a noise level of 45 dB was chosen as the background sound, and three levels of 75, 85, and 95 dB were selected for exposure. The participants were exposed to the determined facial pressure level for half an hour and rested for half an hour after that. During exposure to the noise, the brain waves of the volunteers were used by the portable EEG device Ewave, 16 channels. And the results were analyzed by the mat lab v12 software. The results of the study show that exposure to two levels of 75 and 85 dB of absolute power alpha has increased in 14 brain channels, including CZ and O2 channels. The results showed that the noise level of 75 dB compared to the background state did not change significantly in any of the channels (P>0.05). At the level of 85 and 95 dB, the absolute power of the beta frequency band has increased. At the level of 95 dB, this increase is statistically noticeable and significant in almost all brain regions (P<0.05). Based on the results of this study, it can be said that exposure to noise causes changes in neuronal activities in the brain, and this can affect the performance of the exposed workers.