PURPOSE:  Develop engineering noise controls and a basis for hierarchical recommendations from a noise exposure analysis (NEA) to protect drill operators from hearing loss on non-cab surface drill rigs.

RESEARCH SUMMARY:  Noise induced hearing loss (NIHL) is the most common occupational disease in the United States today, with 30 million workers exposed to excessive noise levels (NIOSH, NORA 1996). Further, NIOSH data indicates that at least 70% of mine workers (also engaged in drilling activities) suffer noise induced hearing loss severe enough to be classified as a hearing disability. There are similar equipment and working conditions that exist at surface drilling sites (water well, construction) which suggest that operators at these locations may also be overexposed. Recent data collected during the period of 2000-2002 by the PRL Hearing Loss Prevention Mobile Unit shows that most surface drilling professionals over the age of 40 have a noise induced hearing loss according to the 1998 NIOSH criterion.

This project concentrates on reducing excessive noise exposures to operators and helpers on various drill rigs that lack noise control devices. Attention to drill operator’s location and activities will lead to the development of an affordable, universally fitted, protective device that protects the operator from over exposure to noise, thus filling the gap between engineering controls, administrative controls, and personal protective equipment. This information can be used to generate educational or training materials to reduce over-exposure to noise while performing surface drilling activities.

Currently researchers are in the process of developing a partial cab that can be attached to drill rigs without a cab. The partial cab has three sides to enable the operator easy access to the drill steel while still offering protection from high sound levels. In laboratory tests, the researchers identified the construction of the partial cab that would yield the highest noise reduction while keeping cost to a minimum. Results of the laboratory tests show that the reductions in the A-weighted sound level ranged from approximately 8 to 15 dB. The Development of a Noise Exposure Analysis (NEA) database for all the field data parameters has been completed. Field site investigations were conducted at eight field sites. Every field site investigation included measuring the drill operator’s noise exposure and documenting a corresponding time-motion, (job activity) study. Findings in the database will be used to evaluate the interdependence between work practices and noise exposure levels.

The outputs and outcomes for this research are as follows: A prototype partial cab will be fabricated and attached to test rigs. Controlled tests will be conducted to ensure testing parameters in the prototype design are confirmed. Field testing of the partial cab in productive environments will then be performed at several sites to confirm the efficiency of the partial cab to reduce operator’s noise exposure levels. The NEA results will be used to develop multiple training products. They will be industry specific and focus on the work practices that have the highest noise exposure levels. These training products will be disseminated to industry representatives through conference presentations, publications and future field work with industry partners.