Impact noise exposure from sheet-metal presses: Manual versus automated production

The noise immission was measured in a sheet-metal pressing plant with large punch-presses, using individual dosimetry in ten workers during sixteen wo rkdays. A comparison was made between the noise doses for workers on a manu al production line, and on an automated line, with five workers on each lin e. Although automation increased the noise emission, we found that the nois e immission to the worker was significantly reduced in the automated produc tion line. The A-weighted equivalent level was 91.2 dB for 6 hours in the m anual production line, and 90.0 dB in the automated lint: (p < 0.05). Howev er, the most important factor in noise reduction among the workers was that the number of noise-exposed workers was reduced from thirteen to six, as a consequence of automation.