Photo credit: Staff Sgt. Jason Hull, Public Domain / United States Department of Defense
by Daniel Fink, MD, Chair, The Quiet Coalition
CNN, among other media outlets, reported at the end of August that 3M, a multinational industry and consumer good conglomerate, settled lawsuits alleging hearing loss and other auditory damage from faulty earplugs supplied to the military for $6 billion.
In a press release, 3M said the agreement “is not an admission of liability.” The company went on to state, “the products at issue in this litigation are safe and effective when used properly. 3M is prepared to continue to defend itself in the litigation if certain agreed terms of the settlement agreement are not fulfilled.”
The earplugs were made by Aearo Technologies, a company acquired by 3M in 2008, and used by the United States military in both training and combat from 2003 to 2015. Unlike earplugs for civilian worker use, the earplugs were dual ended, with one end to protect against all sounds and the other to protect against sounds from explosions while still allowing the soldier to hear commands or enemy sounds. Earplugs made specifically for the military must protect hearing but also allow for situational awareness. But according to the lawsuit, the Aearo earplugs failed to actually protect hearing in the field.
I’m not going to comment on the legal issues, but I want to take this opportunity to discuss earplugs. As the name indicates, earplugs block the external auditory canal to reduce sound transmission to the eardrum. The Environmental Protection Agency rates earplugs using laboratory tests to calculate an average sound level reduction (attenuation) called a Noise Reduction Rating. The Occupational Safety and Health Administration applies a 50% reduction in the rated NRR to provide an additional measure of safety for workers; this adjustment is called derating. Typical earplug NRRs for industrial use are 25-27.
The most important factor in effective earplug use is obtaining a good fit in the external auditory canal. A high NRR won’t protect hearing if the earplug doesn’t fit right. When using earplugs, the sound should be markedly lower than sound heard without earplugs. For exposure to very loud sounds, NIOSH recommends double hearing protection — earplugs and earmuffs. This is not an OSHA requirement, but it’s what I do when using extremely noisy power tools like a hammer drill.
NIOSH mentions the “5 Cs” of selecting hearing protection: Comfort, Compatibility (with the type of work being done), Convenience, Communication (does the worker need to be able to communicate while using the hearing protection) and Cost. For most people trying to protect their hearing when using noisy power tools or appliances, earplug cost shouldn’t be a barrier to use. Reusable corded earplugs cost $2-3 online or in big-box stores. That’s a small price to pay to protect hearing, which is priceless.
Remember, if it sounds loud, it’s too loud and your auditory health is at risk.