Derakhshan Jalil
Background: Noise exposure has harmful effects on physical and mental health as well as cognitive functions. Low-frequency noise is one of the most important sources of noise in the environment. Some individual differences such as extraversion, neuroticism, and sound sensitivity can affect the influences of sound on cognitive functions. The purpose of this study was to investigate the effect of personality type (introversion/extraversion) on cognitive functions in the presence of low-frequency noise.
Materials and Methods: In this interventional study, research population included all students who were studding at Hamadan University of Medical Sciences. For this reason, 120 students were selected through purposive sampling method (60 students with extraverted personality and 60 students with introverted personality). To simulate the real environment of each subject, they were exposed to noise with different sound pressure levels (SPLs) of 50, 60 and 70 dB for 40 min. While the exposure to the determined levels of noise, the continuous visual-auditory performance test was used to evaluate the cognitive functions of the subjects. Data were analyzed using SPSS software (version 20) by independent t-test and ANOVA tests.
Results: The results showed that low-frequency noise negatively affected the components of cognitive functions. These functions decreased with increasing SPL from 50 to 70 dB (P<0.05). The study of the effects of personality type (introversion/extraversion) and gender of the subjects showed that the cognitive functions were more affected in introverts and women and there was a significant difference between the two groups (p<0.05).
Conclusion: The results of this study showed that the SPL of the low-frequency noise has various effects on the cognitive function parameters of individuals with extroverted and introverted personality, and the negative effect of low-frequency noise on introverts was lower than extroverts. Moreover, a significant relationship was observed between noise and gender.