Annunciator

Annunciator means:


 * 1) One that announces, especially an electrical signaling device used in hotels or offices to indicate the sources of calls on a switchboard.
 * 2) (General Physics) a device that gives a visual indication as to which of a number of electric circuits has operated, such as an indicator in a hotel showing in which room a bell has been rung
 * 3) (Railways) a device giving an audible signal indicating the position of a train
 * 4) (Broadcasting) a less common word for announcer
 * 5) (Aviation) An annunciator panel, also known in some aircraft as the Centralized Warning Panel (CWP), is a group of lights used as a central indicator of status of equipment or systems in an aircraft, industrial process, building or other installation. Usually, the annunciator panel includes a main warning lamp or audible signal to draw the attention of operating personnel to the annunciator panel for abnormal events or conditions.


 * Sources: https://www.wikiwand.com/en/Annunciator_panel and http://www.thefreedictionary.com/annunciator.