What type of sound notifies you of a distress call?

A distress call is typically signaled by a warbling sound. This specific sound is designed to catch the attention of operators and distinguish a distress alert from other radio communications. The warbling tone is often utilized in marine distress signaling systems, including those using the Global Maritime Distress and Safety System (GMDSS) and EPIRBs (Emergency Position Indicating Radio Beacons), as it is effective in drawing immediate attention due to its distinctive quality.

In contrast, the other options such as continuous beeps, static noise, and single tones may not be immediately recognized as distress signals. Continuous beeping could be associated with various alerts that are not necessarily urgent, while static noise is generally indicative of poor reception or interference rather than a specific distress signal. A single tone lacks the urgency and uniqueness needed to convey a critical situation effectively. Therefore, the warbling sound is the most appropriate and established signal for indicating a distress call within maritime communication systems.