Effect of an Application of Noise Contour Map in a Rubber Wood Manufacturing Process at Surat Thani province

Abstract

This study aimed to evaluate the noise levels, noise contour mapping and guidelines for wearing personal protective equipment in a rubber wood manufacturing process at Surat Thani province. Sound level measurements were conducted in 6 departments, 771 points by using Sound Level Meter, model SVAN 977A (Class 1) IEC 61672. The noise level measurement result were used to create a noise contour map using the SURFER Software Version 19 program.

Result of the study found that the rubber wood manufacturing process has an average noise level between 74.22 - 92.07 dB(A). When creating a noise contour map in the rubber wood manufacturing process, it was found that the points with measurement results exceeding 85 dB(A) were the wood sawing department, totaling 111 points, accounting for 95.68%, which had an average noise level of 92.07 dB(A). Therefore, the establishment should provide personal protective equipment for employees in the wood sawing department which can reduce noise exposure by using ear muffs, derated NRR was 18.75 dB(A). Sound level of the employee when wearing ear muff was 77.25 dB(A), which was a safe sound level. In addition, a hearing conservation project should be implemented in the factory to reduce risks to employees' hearing performance and there should be an examination of employees' hearing ability to monitor hearing impairment from work.