Fighting parents can be very, very stressful on kids, so we're sorry to hear that you're dealing with this. :( You're not the only one, unfortunately. A lot of kids report feeling horrible while living with parents who are constantly arguing.
First, you need to make sure your parents know how you and your siblings feel about this. You may have told them before, but maybe tell them one more time. Make sure both you and your parents are calm when you talk about it.
Your goal is to relay information to them, so don't lose patience or get too distracted. Just say, "You guys need to know that it's very hard on me/us to hear you fight. I felt it was important to tell you this."
Second, if they continue to fight, do everything you can to keep from getting pulled into the fracas. You don't agree with the fighting, right? So have no part in it. If they begin fighting, get up and leave. Round up your little siblings, too.
If they try to pull you into the fight, tell them you'd rather not fight but you'd be glad to talk to them when they calm down. Once you're away from them, block them out the best you can. Read, listen to music, turn on the TV, etc. Don't get involved.
Third, if possible, be there for your little sibs, too. If you notice they're affected, maybe you and them can settle down in another room and distract each other by watching the TV. If they want to talk about it, give them a few minutes to vent.
We hope this helps a bit. Good luck, and take care of yourself.