they're talking about blasts from open-air combustion shoulder mounted anti-tank weapons.. very nearly artillery, and very loud.[0] . The article linked is the one mentioned in the parent article.

one of the major problems with such weapons is that although the support crew can shield themselves, often the firing soldier cannot due to operation of the weapon.

[0]: https://www.nytimes.com/2023/11/26/us/military-brain-injury-...

SEALs and other special forces use a lot of heavy weaponry and explosives in addition to small arms like rifles and sidearms. Think door breaching charges, grenades, rocket launchers, heavy machine guns.