Which audible device is NOT mentioned among the types of audible devices used in alarm systems?

The correct response identifies visual signals as the option that does not belong to the category of audible devices used in alarm systems. Audible devices are intended to produce sound to alert individuals of an alarm condition, with common examples including electronic sirens, bells, and automated voices that announce warnings or alerts.

Visual signals, such as flashing lights or beacons, serve a different purpose by providing a visual cue rather than an audible one. This distinction is crucial as it highlights the difference between devices meant for auditory alerts and those intended for visual notifications. Hence, while electronic sirens, bells, and automated voices contribute to communicating alarms through sound, visual signals do not fit into this category, making it the correct choice for the question.