Noise in the Shearing Industry


David McBride , Elaine Cowan Margaret Utumapu , John Wallaart


New Zealand Acoustics, 24(2), pp.4- 8 . (2011).

Abstract
The aim of this study was to assess the risk of noise induced hearing loss (NIHL) in shearing and investigate practicable control methods. Woolshed surveys included shed construction data, noise dosimetry and area noise sampling. The noise exposures from 40 personal measurements were all above the 85 dB(A) action level, lying in the range 86-90 dB(A). Shearers had the highest exposure, “near field” noise coming from the action of the cutting edge in the shearing comb, but also from downtubes and gears. Noise for sorters and pressers was contributed to by the stereo system (found in all shearing sheds). Lined sheds seemed to have slightly higher noise levels than unlined sheds. None of the shearing crews had hearing protection available. Redesign of the shearing equipment primarily the handpiece but also the downtubes and gears could potentially reduce the exposure by 2-3 dB(A) and possibly more. In the meantime shearing crews need to wear hearing protection and be subject to audiometric surveillance.