Milad Abbasi, Siavash Etemadinezhad, Ahmad Mehri, Maryam Ghaljahi, Rohollah Fallah Madvari, Roghayeh Jaffari Talaar Poshti,
Volume 10, Issue 2 (5-2020)
Abstract
Introduction: 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.
Material and method: 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.
Results: 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.
Conclusion: The results of this study showed that personality traits such as introversion and neuroticism can affect the sensitivity, annoyance and loudness perception of individuals.
Azar Mehrabi Matin, Mahsa Alefi, Mohammad Reza Monazzam, Adel Mazloumi, Kamal Azam,
Volume 12, Issue 1 (3-2022)
Abstract
Introduction: The noise could affect some aspects of human health, including the cognitive performance. In addition to sound pressure level and exposure time, the psychoacoustic features of noise may cause destructive effects on humans. A few recent studies have been conducted on effect of sound quality on cognitive performance. This study aims to find the noise loudness and sharpness levels as the most destructive effects on human cognitive performance.
Material and Methods: This was a cross-sectional study on 10 male students of Tehran University of Medical Sciences. The Noises were generated in two channels that the left channel produced the pink noise as a background noise. The pink noise loudness and sharpness were 19.7 sone and 2.49 acum, respectively. The right channel generated noises with different loudness and sharpness levels the noise loudness ranged from 8.87 to 67.9 sone and the noise sharpness ranged from 1.07 to 6.4 acum. Finally, ten noises with different loudness and sharpness were applied. The students were exposed to ten different types of noise and a silent condition. The Mathematical Problem Solving Task (MPST) test was performed to assess cognitive performance. The reaction time and the accuracy rate were measured after 5 minutes of noise exposure. Data were analyzed by SPSS (ver. 22). P< 0.05 was considered as significant level.
Results: The mean reaction time and the mean accuracy rate increased with the sharpness level. However, alteration in the loudness and sharpness levels had no significant effect on the speed and accuracy of students. Performance speed increased in noise 3 with the highest loudness (L=67.9, SH=1.07) in comparison with the silent condition (p-value=0.05). The mean accuracy rate in exposure to the noise 9 reduced in comparison with silence (p-value=0.04)
Conclusion: Different levels of psychoacoustic features had no significant effect on the cognitive performance parameters. Although, the accuracy rate and the reaction time decreased in noises 9, the sharpest noise, and 3, the loudest noise, in comparison to the silence, respectively.
