In the world of dreams the rules of reality do not necessarily apply. Each dream is unique and it's a direct link to the soul and spirit. Psychology provides its own theories on what dreams mean, but so did tradition and the study of dreams for thousands of years before any relevant science had developed.
Dream Meanings - Firecracker
If you hear a firecracker in your dream then expect upsetting news, while if you hear many firecrackers going off then expect arguments at home.