NOISE ENGINEERING DESIGN
When hearing protection and administrative controls cannot be employed to reduce noise exposures, EI’s engineering team assists our industrial clients in the identification and design of noise engineering controls. Engineering controls for excessive noise can be developed for isolated pieces of manufacturing equipment or entire industrial process lines. Initial steps require performing sounds level facility surveys and personnel noise dosimeter monitoring of manufacturing personnel by experienced industrial hygienists. Noise monitoring results are utilized to determine specific sources of excessive noise, as well as the mechanism of sound generation/propagation emitted by the excessive noise source. Multiple sources of noise will subsequently be “rank ordered”, which will allow for a range of possible engineering controls, typically addressing the loudest sound sources first. EI’s professionals segregate excessive noise sources into two distinct classes, vibrational noise and noise turbulence.
Once all specific noise sources are identified, EI utilizes the following logical approach to determine the optimal systems to reduce/control excessive noise:
- Substitution of equipment (fundamental first step)
- Categorization of source into vibrational noise and turbulence based noise
- Reduction of driving forces which cause excessive noise
a. Decreasing machine speed
b. Maintaining dynamic balance
c. Provide vibrational isolation
d. Increasing impact duration, while reducing the force of impact
- Reduce response of vibrating surfaces
- Reduce area of vibrating surfaces
- Reorienting directional noise sources
- Reduction in velocity of fluid flow (air ejection systems, valves, vents and piping)
- Provide sound absorption alternatives
- Design and installation of equipment and personnel noise enclosures
Let EI’s team of industrial hygienists and engineers work collaboratively to identify and provide cost-effective engineering solutions reduce exposure of your workforce to excessive noise.
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The National Hearing Conservation Association (NHCA) and the Council for Accreditation in Occupational Hearing Conservation (CAOHC) are widely recognized as the premier organizations in the United States for the promotion of hearing conservation and training of Occupational Hearing Conservationists. NHCA and CAOHC have partnered to provide a series of webinars covering the basics of hearing conservation.
Well before OSHA’s 1983 Hearing Conservation Amendment mandated audiometric testing for noise-exposed workers, audiometric testing in industry was primarily conducted with supra-aural earphones. The term “supra-aural” means that the earphone sits on the ear. This technology has been around for many years; note the earphones worn by this Air Force bomber pilot during World War II.
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On a recent morning news show, Dr. Sanjay Gupta remarked that the local physicians with whom he spoke in Flint, Michigan had never seen a case of lead poisoning during their careers until now.
A Pennsylvania company recently learned of the expensive cost associated with failing to meet OSHA’s hearing conservation requirements.
In Part I of this 2 part blog series, we discussed two well-designed studies published in 2015, in which direct correlations were found between noise exposure levels, hearing loss and risk of injury. Upon reading these study results, the question remains…where does this leave us?
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