While many Americans will be celebrating the annual Fourth of July Independence Day with fun fireworks, a group of veterans are calling on the public to be more mindful about commemorating the event with pyrotechnics. Fireworks tend to trigger post-traumatic stress disorder (PTSD) in many veterans. About 11 to 20 percent of military personnel suffer from the condition every year, according to the U.S. Department of Veteran Affairs.  

"It's an instinct. It's an actual response that they've had conditioned into them over time," said Kenneth Yeager from the Department of Psychiatry in Ohio State Wexner Medical Center, via Fox 28. "They will run for cover or hit the floor. They will protect family members. They will reach for their weapon even though their weapon is nowhere to be found."

But more than the fireworks or lights, the stress is usually brought about by the loud noise. Some veterans can actually enjoy the fireworks display, provided they are told about it beforehand.

Last year, on the Facebook page of Military with PTSD, a member posted a plea, calling on his neighbors to be more courteous with lighting fireworks on July 4 with a sign in front of their house. Her initiative grew into a movement that had other members -- also veterans with PTSD and their families -- distributing similar signs to display in their yards. The signage had the words "Combat Veteran Lives Here" and "Please be courteous with fireworks."

The signs are coming out again this year as Independence Day is fast upon us. Many members from the group are putting these up in their yards again and are encouraging others to do the same.

"I think people wonder how you can be courteous with fireworks. It's not like you can make them quieter," said Shawn Gourley, who spearheaded the movement. Her husband, Justin, was diagnosed with PTSD in 2009 after serving in the Navy from 2000 to 2004. "No veteran that served the United States wants to take a freedom away from people, especially fireworks, which represent freedom. They don't want them to stop. What they're asking for is for people to give them a heads up." Gourley said, according to CNN.