I found "Dubs Acoustic Filters" on Amazon and they have been a life saver for me post concussion! The only drawback for me is I talk softer than I realize as I think I'm talking louder than I am.

My concussion doctor suggested musician ear plugs and I found these within my price range for what I needed (conversations - I'm not a musician).

These work in restaurants, waiting rooms (dang TVs in waiting rooms and talking people) They filter out loud background noise so I can focus on the conversation I want to listen to or the waitstaff or the medical staff helping me.

I've even used these to go to a movie (ONCE - and then I also used ear muffs - closed my eyes - Star Wars - well at least I got to be with my family!)