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 workdays. A comparison was made between the noise doses for workers on a manual production line, and on an automated line, with five workers on each line. Although automation increased the noise emission, we found that the noise immission to the worker was significantly reduced in the automated production line. The A-weighted equivalent level was 91.2 dB for 6 hours in the manual production line, and 90.0 dB in the automated line (p < 0.05). However, 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.