Timber harvesting activities are unquestionably related with high risk of work accidents and health disorders.
Such activities were not only burdened the workers with heavy physical workloads due to uneasy working
environment, and massive work materials and tools, but also physiopsychologically burdened workers as they
were imposed with both mechanical and acoustic vibrations (noise) produced by the chainsaw. However, it is a
common practice that most of the workers still ignored the importance of the use of noise reduction devices such
as earmuff or ear plug. This study was aimed to reveal the factual effects of noise on work concentration of the
workers to provide a scientific basis in supporting efforts in improving workers’ attitude. The results confirmed
that chainsaw might produce noise during operation. Noise intensities received by both right and left ears were
not significantly different, indicating that left-handed and normal workers received similar degree of noise in
both side of ears. Further, results also showed that there was a significant difference on the perception and work
concentration of chainsaw operators versus sedentary people to the noise. These findings proved that hearing
ability of chainsaw operators had declined due to frequent noise exposure.
Keywords: timber harvesting, physio-psychological disorder, noise, chainsaw