The Effect of Noise Exposure on Cognitive Performance and Brain Activity Patterns

Abstract

Background: It seems qualitative measurements of subjective reactions are not appropriate indicators to assess the effect of noise on cognitive performance. In this study, quantitative and combined indicators were applied to study the effect of noise on cognitive performance. Materials and Methods: A total of 54 young subjects were included in this experimental study. The participants’ mental work load and attention were evaluated under different levels of noise exposure including, background noise, 75, 85 and 95 dBA noise levels. The study subject’s EEG signals were recorded for 10 minutes while they were performing the IVA test. The EEG signals were used to estimate the relative power of their brain frequency bands. Results: Results revealed that mental work load and visual/auditory attention is significantly reduced when the participants are exposed to noise at 95 dBA level (P<0.05). Results also showed that with the rise in noise levels, the relative power of the Alpha band increases while the relative power of the Beta band decreases as compared to background noise. The most prominent change in the relative power of the Alpha and Beta bands occurs in the occipital and frontal regions of the brain respectively. Conclusions: The application of new indicators including brain signal analysis and power spectral density analysis is strongly recommended in the assessment of cognitive performance during noise exposure. Further studies are suggested regarding the effects of other psychoacoustic parameters such as tonality, noise pitch (treble or bass) at extended exposure levels.