How have combat units in major modern wars not all end up deaf?

I've thought about this many times. How have combat units in wars, WWI/WWII especially (since they generally saw the most direct combat) not end up with all the soldiers being deaf or at least with severe hearing loss? It seems like that's something that is not really ever talked about.

I have an 8mm Mauser that I made the mistake of firing one time without earplugs and my ears rang for a long time- and that's an example of a typical rifle that there would have been dozens of in a firefight, not to mention explosions, etc.

We've all seen the movies where guys have a firefight and then have low-voiced conversations afterward, is that all BS? Those guys couldn't have been able to hear anything.

edit: So damn guys, this blew up (no pun intended) way more than I ever anticipated. Thanks for all your replies!