Annunciator [1]

A signaling device, capable of delivering an audible message or signal to the person using the device.

Suppose you drive into a self-service station and begin the process of purchasing gasoline [2] by inserting your credit card into a card acceptor [3] and that a recorded voice then instructs you to punch in the number of the dispenser [4] you intend to use. The technical equipment that allows the system to give you these oral instructions is referred to as an annunciator.