An Acoustic Hailing Device (AHD) is a tool used primarily for communication over long distances. It emits loud, directed sound waves to convey messages or warnings to individuals or groups, often in maritime or military contexts. The device can be used to communicate with vessels, aircraft, or people in situations where traditional communication methods may not be effective. AHDs are designed to be portable and can produce sounds at high decibel levels, making them effective in noisy environments. They are often used by law enforcement, the military, and search and rescue teams to ensure clear communication and enhance safety during operations.