Evaluation of the effect of noise on the rate of errors and speed of work by the ergonomic test of two-hand co-ordination.
BACKGROUND
Among the most important and effective factors affecting the efficiency of the human workforce are accuracy, promptness, and ability. In the context of promoting levels and quality of productivity, the aim of this study was to investigate the effects of exposure to noise on the rate of errors, speed of work, and capability in performing manual activities.


METHODS
This experimental study was conducted on 96 students (52 female and 44 male) of the Isfahan Medical Science University with the average and standard deviations of age, height, and weight of 22.81 (3.04) years, 171.67 (8.51) cm, and 65.05 (13.13) kg, respectively. Sampling was conducted with a randomized block design. Along with controlling for intervening factors, a combination of sound pressure levels [65 dB (A), 85 dB (A), and 95 dB (A)] and exposure times (0, 20, and 40) were used for evaluation of precision and speed of action of the participants, in the ergonomic test of two-hand coordination. Data was analyzed by SPSS18 software using a descriptive and analytical statistical method by analysis of covariance (ANCOVA) repeated measures.


RESULTS
The results of this study showed that increasing sound pressure level from 65 to 95 dB in network 'A' increased the speed of work (P < 0.05). Increase in the exposure time (0 to 40 min of exposure) and gender showed no significant differences statistically in speed of work (P > 0.05). Male participants got annoyed from the noise more than females. Also, increase in sound pressure level increased the rate of error (P < 0.05).


CONCLUSIONS
According to the results of this research, increasing the sound pressure level decreased efficiency and increased the errors and in exposure to sounds less than 85 dB in the beginning, the efficiency decreased initially and then increased in a mild slope.
Department of Occupational Health Engineering, School of Health, Isfahan University of Medical Sciences, Isfahan, Iran.
Ehsanollah
E
Habibi
Habibollah
H
Dehghan
Sina Eshraghy
SE
Dehkordy
Mohammad Reza
MR
Maracy
Ergonomics; noise; rate of error; speed of work; two-hand coordination.