Mining Project: Engineering Noise Controls for Haul Trucks and Load Haul Dumps (LHD’s)
The purpose of this project is to develop, evaluate, and implement engineering controls to reduce noise over-exposures among haul truck and LHD operators. This will contribute to a long term goal of reducing Noise Induced Hearing Loss.
|Keywords||hearing loss, mining, noise|
Previous NIOSH survey results indicated that more than 90% of underground metal equipment operators were over-exposed to noise according to the MSHA permissible exposure level. Haul truck and LHD operators were particularly at risk, with typical noise doses exceeding 200% on average. Noise over-exposure can lead to noise-induced hearing loss (NIHL).
The purpose of this project is to develop, evaluate, and implement engineering controls to reduce noise over-exposures among haul truck and LHD operators. The project will have five phases:
Phase 1. Early research focused on field studies to quantify noise dose accumulations and noise sources. Time-motion studies determined the causal relationship between job task and noise dose accumulation. NIOSH collected sound pressure and sound intensity measurements to determine which sources should be addressed initially. In addition, sound power level testing was conducted in the laboratory to evaluate the overall noise emission of the haul trucks and LHD’s.
Phase 2. NIOSH will develop a working relationship with equipment manufacturers to address the noise sources that are prominent contributors to operator noise doses. Noise controls expected to be original equipment or available for retrofit will be developed through agreements with manufacturers. Less complicated noise controls will be developed in-house by NIOSH.
Phase 3. This phase will overlap with Phase 2. As noise controls are developed, they will be laboratory-tested and those with promise will be field tested. This sound pressure and sound power testing should confirm reduction in noise emissions. Field time-motion studies will be conducted to quantify the expected reductions in noise exposures.
Phase 4. Licensing and distribution will be finalized with a collaborating manufacturer. Noise controls developed in-house will be documented and shared on the NIOSH web pages, and MSHA will be provided with data.
Phase 5. Noise controls will be formally evaluated to determine their effectiveness in reducing noise exposures and/or inducing behavioral changes in the work force.