3M Combat Arms Earplugs

Over the years, the 3M Combat Arms design has been proven to be defective, resulting in hearing loss to service members.

Millions of pairs of 3M’s Combat Arms, Version 2, earplugs were sold over the years to the United States military before their defects became known to the public.

Over 250,000 lawsuits have been filed against 3M, and were consolidated into a multi-district litigation. With millions of dollars paid out in settlements and verdicts to service members who had suffered hearing loss and other auditory injuries after using the earplugs, 3M’s defects have become one of the biggest mass torts in United States history.

• July 1999 – Aearo Technologies, Inc. first began selling its CAEv2 earplugs to the United States military
• July 2000 – An internal report, known as the Flange Report, documents the earplug’s defects which prevents the user from properly inserting the plug in their ears¹
• 2003-2015 – The United States government provided the Combat Arms Earplugs, Version 2, to all branches of the military, especially during the Iraq and Afghanistan wars²
• 2003 – The United States Marine Corps issued over 20,000 pairs, temporarily depleting the entire stock
• April 2008 – 3M acquires Aearo Technologies, Inc.³
• May 2016 – A whistleblower lawsuit is filed against 3M for making false statements about the safety of the earplugs and for knowingly selling them despite the design defect
• July 2018 – 3M enters into a settlement agreement for $9.1 million without admitting wrongdoing⁴
• April 2021 – A jury awards three plaintiffs a total of $7.1 million in damages in the first of several bellwether trials
• May 2021 – 3M wins its first bellwether trial
• June 2021 – A Florida jury finds 3M 62% liable for failing to provide adequate warnings
• October 2021 – A Florida jury awards a U.S. Army sergeant $8.2 million in damages; 3M wins another at another trial
• January 2022 – Two U.S. Army veterans are awarded $110 million in damages

Noise-induced hearing loss due to military conflicts has long been recognized as a significant source of physical disability for service members.

In particular, the use of improvised explosive devices (IEDs), mortar rounds, and rocket-propelled grenades during the Iraq and Afghanistan wars emphasized the need for effective hearing protection during combat. First developed by Aearo Technologies (which was later bought by 3M) Combat Arms Version 2 earplugs were designed to address this very problem.

The earplugs were designed to block harmful sounds, such as gunshots and explosions, while allowing the user to hear voice commands. After their initial development, the length of the earplugs was shortened to fit the U.S. Army’s standard issued carrying case.

Sound attenuation testing was never performed on the shortened version and only testing data of the previous earplugs were provided to the U.S. military. Testing found that the earplugs were not providing adequate protection against hearing loss because the length of the plug was too short.

How do 3M Earplugs Work?

The way the earplugs work is that one side is inserted in the ear for protection, and the other side was for hearing the commands. With the shortened version, one end (the green end) was too short for proper insertion. To compensate, the manufacturer altered the shape of the other end (the yellow end) by folding the flange outward.

The flange of the earplugs were supposed to provide a sealed fit. However, the flanges, which were supposed to fold over, would return to their original position, breaking their protective seal. Once the seal was broken, the user would oftentimes be unaware that the seal was not providing adequate protection.

The lawsuits allege that both Aero Technologies Inc. and 3M knew about the design defects but continued to sell the earplugs. To the military, the earplugs were thought to be so effective that the U.S. Marine Corps temporarily depleted the entire national stock in 2003 when it ordered over 20,000 pairs.⁶

What Causes Hearing Loss?

Noise-induced hearing loss is permanent and results from long-term exposure to a noisy environment. The total amount of noise a person can be exposed to is based on the pressure generated by noise (in decibels) and the amount of time exposed. In general, sounds over 85dB can cause noise-induced hearing loss. Early signs of damage can be reversed if the person leaves the noisy environment.

Hearing loss becomes permanent once hair cells of the ear (which are responsible for the perception of sounds) are killed off.

• In the cases of service members who are exposed to high-intensity sounds during short durations, the damage can occur immediately by perforating the tympanic membrane of the ear.

Another factor in hearing loss is that high-intensity noise causes the fluids in the ear to shift, resulting in a separation of the inner and outer hair cells, which impacts the ear’s ability to receive the vibratory stimulation it needs to properly hear.

• Hearing loss
• Tinnitus (ringing in the ears)
• Hyperacusis (increased intensity of sound)
• Depression
• Social withdrawal
• Sleep disturbances
• Exacerbation of PTSD

Tinnitus and hearing loss account for the two most common injuries experienced by veterans, with approximately 2.3 million and 1.3 million claims, respectively. Other complications include:

These injuries lead to other comorbidities, such as post-traumatic stress disorder, anxiety, and depression. The Veteran Benefits Administration reported that in 2020, over 3.6 million received disability payments for hearing impairments.

• Ages between 30 and 49 – injury typically occurs in active duty service
• Mostly males, as tinnitus is more common in males
• Hearing loss and/or tinnitus as primary diagnosis
• Multiple years of earplug use
• History of military service⁶

• Ensure that any earplugs recreated for expert evaluation and simulation testing are the same fit (and subject to the same conditions) as the original 3M earplugs
• Obtain the services of an otolaryngologist and audiologist to diagnose and treat any auditory condition
• Obtain the services of a neuro-otologist to diagnose any pathological conditions associated with auditory damages
• An industrial hygienist can determine noise attenuation standards and the acceptable levels of noise exposure in a workplace
• Acoustic engineers can test the efficacy of hearing-protective devices