Between 2003 and 2015, the US military Combat Arms was supplied earplugs by Aearo Technologies, Inc., and its parent company 3M. The earplugs were provided to service members to protect their hearing from the loud noises of combat and training.

The earplugs were standard issue for troops in Iraq and Afghanistan, yet based on a whistleblower suit brought by a competitor, 3M and Aearo were aware the earplugs were defective; they did not meet mandated standards of protection.

3M settled with the US Military in 2018. After this settlement, individual service members began filing suits for a variety of hearing loss issues and tinnitus (incessant ringing or other noise in the ear).

Current accounts cite between 230,000 and 300,000 veterans were affected and have filed lawsuits with similar claims – so many that they were centralized under a Florida court into an MDL (multi-district litigation: a consolidation which streamlines complex civil lawsuits based on the same defendant conduct).