The purpose of this study is to evaluate the difference of noise level according to noise measuring methods in the noisy working environments. Sound pressure level(SPL), equivalence sound level(Leq) and personal noise exposure dose(Dose) in the fifty-nine unit workplaces of the twenty-eight industries were measured and relating factors which were affected noise level were investigated.
The results were as follows ;
1. The noise levels were 88.70±5.68㏈(A) by SPL, 89.07±5.41㏈(A) by Leq and 89.07±5.69 by Dose. The differences of noise levels by three measuring methods were statistically significant(P$lt;.001) by repeated measure ANOVA.
2. Comparing with noise levels by general classes of noise exposure, noise levels of continuous noise were 89.14±5.19㏈(A) by SPL, 89.45±5.65㏈(A) by Leq and 90.04±5.09 by Dose. Noise levels of intermittent noise were 87.90±6.52㏈(A) by SPL, 88.40±6.63㏈(A) by Leq and 90.10±6.80 by Dose. The differences noise level of noise measuring methods by general classes of noise exposure were statistically not significant by repeated measure ANOVA.
3. Interaction between general classes of noise exposure and noise measuring methods for noise level was not statistically significant by repeated measure ANOVA. And the noise level by noise measuring methods were statistically significant by repeated measure ANOVA(P$lt;.001)
4. Comparing with noise levels by unit workplace size, noise levels of large unit workplace were 90.73±5.87㏈(A) by SPL, 91.32±5.50㏈(A) by Leq and 91.82±6.06 by Dose and noise levels of middle unit workplace were 88.31±5.26㏈(A) by SPL, 88.41 ±4.83㏈(A) by Leq and 89.69±5.05 by Dose. And noise levels of small unit workplace were 94.89±4.10㏈(A) by SPL, 85.35 4.11㏈(A) by Leq and 86.87±4.98 by Dose. The noise level differences of noise measuring methods by unit workplace size were statistically significant by repeated measure AVOVA(P$lt;.05).
5. The noise level by noisy measuring methods were statistically significant by repeated measure ANOVA(P$lt;.001). But Interaction bwtween workplace size and noise level measuring methods for noise level was not statistically significant by repeated measure ANOVA.
Acceding to the above results, there was a difference of the noise level among the three measuring methods. Therefore we rose the personal noise exposure dose using by noise dose meter, possibility, to prevent occupational hearing loss in noisy working environment.
|