Selecting hearing protectors
Your selection of hearing protection devices should be based on a thorough evaluation of noise conditions in your workplace using proper sound analysis. Rochelle A. Crew of Emilcott Associates, Inc. offers these basic considerations:Type of noise: Noise Reduction Ratings (NRRs) of hearing protectors should be evaluated in terms of effectiveness against specific frequencies of noise, not just the total amplitude in decibels. You need to discern if the noise is continuous, intermittent, or impulse, and whether it is mostly high-frequency or low-frequency rumble.
Warning sirens, signals, and speech: Consider whether employees have to be able to detect warning sirens, signals, and speech, because in some circumstances hearing protectors can create a new hazard by interfering with audible warnings and communication.
Conditions of work: Your work environment influences what protectors will be appropriate. Workers who don't have access to handwashing facilities should be careful about using foam earplugs because dirt can be transferred from fingers to earplugs and then to ears. Earmuffs can interfere with other personal protective equipment or may be uncomfortable in cramped spaces.
Comfort and acceptance:
Hearing protectors are effective only when worn consistently. Remember, some users find earmuffs intolerable, or can't stand to stick anything into their ear canal. Always make sure that the protectors are the right size and fit for your employees.
Justifying engineering controls
Lee Hager of James, Anderson & Associates, Inc., disputes the large expense often associated with engineering controls. Estimates indicate that designed-in noise control for new construction can be as little as five percent of the total costs, he says.Also, experts say the cost of controls should be weighed against the steady expense over years for PPE, annual audiograms and medical follow-up, and lost employee time due to training, audiometric testing, and program administration. Engineering controls remove the hazard while the effectiveness of personal protectors depends on worker acceptance, supervisory monitoring, training, and choosing the right product for the application.
Noise control engineering measures also provide secondary benefits, according to Crew. Balancing motors, reducing excessive machine vibrations, and keeping equipment in good working order improves performance and prolongs the useful life of expensive equipment.
Motivating employees
"TrainingÉtrainingÉtraining" is how Norm Brusk of Health and Safety 2000 sums up convincing employees of the importance of wearing hearing protectors. Employees need to know how noise affects hearing and why."To demonstrate what hearing loss is like I often start mumbling and talking a bit softer sometime during my presentations. Employees begin to strain to hear what I am saying, but won't be able to understand the words. This often gets their attention!" he says.
Since many people do not realize the level of noise they are exposed to on a routine basis, you might want to show them printouts of personal or area noise monitoring. Crew recalls one employee who had a substantial peak right on his lunch hour. Turns out he spent his lunch time in his van, listening to heavy metal music on a high-powered stereo system.
Conducting hearing tests
OSHA provides detailed guidance for the proper conduct of hearing tests in the Hearing Conservation standard (29 CFR 1910.95). But Crew says that there are four important key issues to keep in mind:1."Quiet Time" - OSHA requires a period of 14 hours without high noise exposure before a baseline hearing test.
2."Quiet Room" - You cannot use just any "quiet room" for testing because there are many background noises, such as footsteps in a hallway or planes flying overhead, or sound interference from an HVAC system. Appendix D of the standard gives the maximum noise levels permitted in the test chamber.
3.Trained Technicians - Ideally, testing technicians should be trained and certified by the Council for Accreditation of Occupational Hearing Conservationists (CAOHC). OSHA does permit the use of non-certified technicians on microprocessor-controlled audiometers.
4.Scrupulous Recordkeeping - Modern microprocessor-based audiometers can save test results and download them to a computer database for analysis and archiving. But a "hard copy" should always be maintained, just in case.
