Noise reduction on a jumbo drill using panel contribution analysis and scale modeling

During drilling operations, jumbo drill noise levels are in excess of 95 dBA in mining environments. Panel contribution analysis was used to determine which components contribute the most at two receiver positions. The primary contributors to the high noise levels were the drifter or gearbox, and a hydraulic pump in a steel enclosure just behind the operator. Panel contribution analysis combined with scale modeling revealed that the pump enclosure was the primary source of noise. Lagging was added and the noise at the operator ear was reduced by 4.3 dBA constituting a first step towards reducing sound pressure levels below 90 dBA. The results demonstrated the feasibility of using panel contribution analysis combined with scale modeling to identify noise controls and their impact even if a large anechoic chamber is not available. Key.