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Introduction: Sound is among the significant environmental factors for people's health, and it has an important role in both physical and psychological injuries, and it also affects individuals' performance and productivity. The aim of this study was to determine the effect of exposure to high noise levels on the performance and rate of error in manual activities. Methods: This was an interventional study conducted on 50 students at Shiraz University of Medical Sciences (25 males and 25 females) in which each person was considered as its own control to assess the effect of noise on her or his performance at the sound levels of 70, 90, and 110 dB by using two factors of physical features and the creation of different conditions of sound source as well as applying the Two-Arm coordination Test. The data were analyzed using SPSS version 16. Repeated measurements were used to compare the length of performance as well as the errors measured in the test. Results: Based on the results, we found a direct and significant association between the levels of sound and the length of performance. Moreover, the participant's performance was significantly different for different sound levels (at 110 dB as opposed to 70 and 90 dB, p < 0.05 and p < 0.001, respectively). Conclusion: This study found that a sound level of 110 dB had an important effect on the individuals' performances, i.e., the performances were decreased. [ABSTRACT FROM AUTHOR]

The purpose of this study was to evaluate the self-care assessment questionnaire that is used to study the level of self-care in healthy adults. In the first stage, the self-care assessment questionnaire was translated from English to Persian using the forward-backward method. The final Persian version was evaluated in terms of translation clarity, compliance with Iranian culture, and consistency with concepts in the original version. Subsequently, the psychometric properties of the tool were determined. During the translation and localization process, changes were made to the Persian version for a better understanding. The Cronbach's alpha coefficient of the different dimensions of the tool was within the desired range (0.782-0.924). Considering the importance and necessity of a self-care assessment questionnaire in healthy adults, a comprehensive and multidimensional questionnaire was selected and localized. This questionnaire can be used to improve the level of health and self-care. [ABSTRACT FROM AUTHOR]

Both natural and synthetic fibers do not perform well at low frequencies and are also subjected to erosion, moisture, fire, etc., when used as an interior finish of room walls. To overcome these problems, micro-perforated plate with different thickness is used in a multilayer sound absorber configuration to improve its sound absorption. Firstly, the acoustic properties of five natural wastes including sheep wool, goat wool, camel wool as well as pith and fiber bundles of sugarcane bagasse were determined by using an impedance tube following ISO 10534–2. Secondly, the effect of Panel thickness was investigated. The maximum sound absorption coefficient (SAC) of natural waste materials is at middle to high-frequency range and this shifted to lower frequency as the porous layer thickness increases. The sound absorption performance depends on the thickness of perforated plate and porous layer in a compound sound absorber. It is observed that the using perforated plate in the front of low thickness porous materials significantly improve the SAC and absorption bandwidth. However, it should be noted that this reduces the SAC at high frequencies. Accordingly, the thick micro-perforated panels backed by porous layer are not recommended to control sounds with frequency higher than 3000 Hz. [ABSTRACT FROM AUTHOR]