I fired a 50 as part of my job for years, it is nothing like the effects of being near arty being fired. I can't speak to being in an IED blast, but I can speak to being concussed. Yes, the 50 is loud. With hearing protection, I never felt an effect. Whacking my head playing hockey, a motorcycle crash, being knocked out fighting... all of these felt like something. So did being near arty.

One of the things that is becoming apparent in football CTE is that damage is not limited to the big hits, the chronic effects of smaller hits are causing damage.

https://www.nytimes.com/2023/06/20/sports/football/cte-study...