Im lucky that where I live I can only hear faint booms. Our fireworks on the 1st (Im Canadian!) were actually louder than usual, especially the grande finale but my buns didnt really seem to notice. Sometimes I attend the fireworks but I opted to stay home this year. Quite often here, we have amateurs using store bought fireworks but my buns dont really get upset by them. Which is funny, because Olivia will stomp repeatedly if she hears us eating croutons or any little tapping sounds.
I would just stay with them during the fireworks and talk to them reassuringly. Not really sure what else you could do. You could try the TV.
In a way, I hate fireworks because of how they affect animals. A few years ago, I went downtown to watch them and there was a few people that had dogs. Those poor dogs were absolutely terrified. How can people be so dumb as to think they would enjoy that? For an animal, up close, it must feel like a war zone.