The Effect of Exposure to High Noise Levels on the Performance and Rate of Error in Manual Activities.
BACKGROUND
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).


CONCLUSIONS
This study found that a sound level of 110 dB had an important effect on the individuals' performances, i.e., the performances were decreased.
Ph.D. of Occupational Health, Assistant Professor, Department of Community Medicine, School of Medicine, Tehran University of Medical Sciences, Tehran, Iran.
Farahnaz
F
Khajenasiri
Department of Ergonomics, School of Health, Shiraz University of Medical Sciences, Shiraz, Iran.
Alireza
A
Zamanian
Ph.D. of Occupational Health, Associate Professor, Department of Ergonomics, School of Health, Shiraz University of Medical Sciences, Shiraz, Iran.
Zahra
Z
Zamanian
activities; coordination test; error; manual; noise; performance