2019 NHCA Annual Conference has ended
Back To Schedule
Friday, February 8 • 4:00pm - 4:20pm
Sometimes 85 Is Just A Number, But Sometimes It's More. And, Sometimes It's Less.

Sign up or log in to save this to your schedule, view media, leave feedback and see who's attending!

Feedback form is now closed.
The 1994 NIOSH publication Preventing Hearing Loss: A Practical Guide suggested that the maximum noise-exposure level should be 85 dBA Leq,8. Occupational Noise Exposure, Revised Criteria 1998, made that suggestion a formal NIOSH Recommended Exposure Limit. Since then, many other countries, most recently Canada, have adopted the NIOSH REL as a Permissible Exposure Limit.   There are two common confusing misuses of the value of 85 dBA. The first is labeling it as safe. At a working-life exposure level of 85 dBA Leq,8 between 8 and 12 percent will develop material hearing impairment. A safe noise-exposure level with 0 percent developing material work-related noise-induced hearing loss, it would have been 75 dBA Leq,8.  The second misuse is confusing an exposure level for a noise level. An exposure level is determined by averaging noise levels over a specified time, hence the  equivalent level for 8 hours. A noise level is of little value since the time of exposure is not specified. This type of misuse is often found in the safety portion of earphones along with what would be fairly entertaining descriptions of how to determine the output level if the hearing of the consumer weren't at risk.


John Franks, Ph.D.

Dr. Franks is the former Chief of the Hearing Loss Prevention Section of the National Institute for Occupational Safety and Health (NIOSH). While at NIOSH he directed the nation‚Äôs research into the improvement of hearing protectors and testing methods, directed the national... Read More →

Friday February 8, 2019 4:00pm - 4:20pm PST
Grapevine A