What does the emergency evacuation signal consist of?

The emergency evacuation signal is designed to effectively alert individuals to evacuate the premises quickly and safely. The choice that indicates short blasts of the air horn followed by silence is correct because this method provides a clear and recognizable signal that can cut through background noise, ensuring that those present can identify the urgency of the situation.

Short blasts of an air horn are commonly used in emergency situations because they can be easily heard over traditional noises and are distinct enough to capture immediate attention. The resulting silence after the blasts allows for the signal to be distinct and not confused with other sounds. In contrast, continuous loud alarms, sirens with flashing lights, or voiced announcements might not convey the same immediate sense of urgency or could be diluted by surrounding noise or other alarm systems currently in operation. Therefore, the specific sequence of air horn blasts followed by silence is effective in creating an unambiguous evacuation signal that prompts swift action.