If you work in a loud environment, such as a construction site, a factory or an airport, your ears may be subjected to too much noise on a daily basis. I’m no ear expert, but I’m guessing that this kind of situation cannot be doing your hearing any good. There are headphones on the market designed to muffle loud noises. Some may be sold as “noise-cancelling”, but this doesn’t necessarily mean it will eliminate all noise.
I like how bright and visible these are:
Construction noise-cancelling headphones pictured: 3M Peltor Optime 98 Earmuff