What characteristic is crucial for audible trouble signals?

Audible trouble signals are designed to prompt attention without being confused with alarm signals, which indicate immediate danger or emergencies. The primary characteristic that makes trouble signals effective is their distinctiveness from alarm signals. This clarity allows responders to differentiate between a situation that requires urgent action versus one that indicates a problem requiring investigation, such as equipment malfunction or system issues. Distinctiveness ensures that personnel can quickly assess the nature of the alert and respond appropriately.

While consistency in sound, volume control, and timing might contribute to the overall effectiveness of a signal, they do not address the fundamental necessity of preventing confusion between signals that denote immediate threats and those indicating issues needing attention. The unique sound characteristic ensures that a trouble signal is recognized as non-emergency, guiding the appropriate response.