Xstrata said in its 2007 sustainability report that NIHL was the most extensive occupation illness "by far" in the mining industry.
At Xstrata Coal South Africa's Tavistock complex, which consists of both underground and open cut mines, load haul dumper operators are exposed to high levels of noise.
Although the operators are provided with hearing protection devices, noise emission measurements of a typical LHD underground show an average operator exposure of 97.7 decibels.
During 2007, engineers from Xstrata Coal South Africa redesigned the LHD to change from an open air cabin with the driver located directly in front of the engine to an enclosed, ventilated cabin.
The new cabin has reduced operator exposure to 72.9dB, a level that eliminates the need for operators to wear hearing protection.
However, some challenges still remain. During trials it was discovered that the driver’s view was obstructed by the roof framework and condensation on the windows. Engineers are now working to overcome these challenges.
Xstrata Coal SA has set its own target for the elimination of NIHL: by December 2013, the total noise emitted by all equipment installed in any workplace will not exceed a sound pressure level of 110dB.