The sounds of firecrackers and gunshots are pretty common where I live, so Chimera has grown up with them and never showed sensitivity to them before. He also didn't worry during New Year's Eve. However the fireworks are much more intense on July 4th. I had the early evening free to do intense gardening for a couple of hours, so I put Cai on a tie out with me and kept an eye on him. He chewed on a bully stick for a while, walked around, and then stretched out on a welcome mat and fell asleep. It was amazing. The fireworks are now exploding non-stop, including ones on the street right outside my window, and he's falling asleep again on my bed. Occassionally he does swivel his ears or look around, but it's curiosity/confusion and not stress. I am beyond impressed.
Here are a couple of pictures from our hike this afternoon. This fallen tree was about three feet up in the air. Too bad the camera didn't focus on his face. Click on either picture to see it pop up in a bigger size.