رقیه جعفری تالارپشتی

 Although noise characteristics such as intensity and frequency are the main cause of detrimental effects, it is important to pay attention to the personality traits of individuals as the host of adverse health effects. The aim of this study was to investigate the effect of personality traits on sensitivity, annoyance and loudness perception due to exposure to high frequency sound.

 This interventional and experimental study was carried out among 80 undergraduate and postgraduate students in 2017. First, examinee were exposed to a high frequency noise at 65 dBA for one hour in an acoustic room. Then, to determine amount of annoyance, sensitivity, loudness perception and to investigate personality traits, questionnaire of noise annoyance, noise sensitivity, loudness perception and Eysenck personality inventory was used, respectively. Finally, Chi-square, independent t-test and multivariate analysis of variance (MANOVA) were used to data analyze.

 The mean±SD of sensitivity, annoyance and loudness perception were 54.08±7.71, 7.0±1.53, and 2.79±1.13, respectively in this study. The mean scores of sensitivity, annoyance and loudness perception were significantly different in terms of personality traits, so that their average was higher in the neurotic and introverted. Based on MANOVA test results, personality traits had a significant effect on sensitivity, annoyance and loudness perception of individuals. In a way, the neuroticism and introversion had the greatest effect on the sensitivity and annoyance, respectively.

 The results of this study showed that personality traits such as introversion and neuroticism can affect the sensitivity, annoyance and loudness perception of individuals.

Low-frequency noise as a detrimental occupational and environmental factor which can cause noise annoyance. In addition to noise, factors such as sensitivity and awareness of adverse health effects of noise seem to play an important role in causing annoyance. Therefore, this study aimed to investigate the association of noise annoyance and loudness perception caused by exposure to low-frequency noise with noise sensitivity. To achieve this goal, 80 students were exposed to low-frequency noise exposure at 65 dBA in an acoustic room. After one hour of exposure, the subjects completed the Weinstein's Noise Sensitivity Scale, Loudness Perception Scale, and Noise Annoyance Scale. Data were analyzed using Mann-Whitney, Kruskal-Wallis test and the Multivariate Analysis of variance (MANOVA). The results showed that the mean score of noise annoyance and loudness perception was significantly higher in the group with high noise sensitivity. Also, increasing the awareness of the harmful effects of noise significantly increased the level of annoyance and loudness perception of individuals. The results of MANOVA showed that noise sensitivity has a significant effect on both the response variables. Also, awareness of the harmful effects of noise only affects loudness perception. The interaction effect of two independent variables was not significant on any of the response variables . In general, it can be concluded that noise sensitivity and awareness of the harmful effects of noise are two important factors that exacerbate the annoyance caused by exposure to low-frequency noise.

Chronic occupational noise exposure may constitute a risk factor for cardiovascular disease for workers. The aim of this study was to investigate the relationship between occupational noise exposure and noise annoyance with blood pressure, serum cholesterol and triglyceride levels in workers of a textile industry. Material and Method: This cross-sectional study was carried out among 220 employees of Savadkouh textile industry complex in Mazandaran province, Iran in 2017. To achieve the study objectives, the 8 -hour equivalent sound exposure level was measured and the cumulative noise exposure was calculated. Based on noise exposure level, workers were divided into control and case groups. Then, blood pressure was measured and blood samples were collected from each individual for determination of the serum cholesterol and triglyceride levels and they were transfered to the laboratory for further analysis. The noise annoyance scale and socio-demographic questionnaire were used to collect noise annoyance and other background and demographic information, respectively. Finally, Paired t-test, one-way ANOVA and multivariate regression were used to study the relationship between variables using SPSS Version 20. In total, 159 workers participated in this study considering the inclusion and exclusion criteria. Eighty-three participants were exposed to more than or equal to 85 dBA, and 76 person were exposed to less than 85 dBA noise level, respectively. The results showed that mean blood pressure and cholesterol were significantly different between the control and case groups (P-value< 0.05). Based on multivariate regression results, noise exposure, cumulative noise exposure (CNE) and noise annoyance had a significant effect on blood pressure (P-value< 0.001). Cholesterol was also significantly affected by noise exposure and noise annoyance (P-value< 0.005). Based on the results of current study, noise can be considered as a risk factor for cardiovascular disease ampong workers. Actually, high intensity noise affect serum cholesterol and blood pressure directly, and may do indirectly by causing noise annoyance which acts as a mediator. Therefore, it seems necessary to conduct a controlled cohort study to investigating the interactions among whole variables of interest.