The communicator is a fictional device used for voice communication in the fictional universe of Star Trek. As seen in at least two instances, the Original Series episodes "Tomorrow Is Yesterday" and "Day of the Dove," it can also serve as an emergency signaling device/beacon, similar to a transponder.

What is a communicator?

: one that communicates something Nor was Stroheim alone during the twenties in exploring the possibilities of the camera as communicator rather than manipulator.— James Monaco especially : a person who conveys information or knowledge to others A true leader needs to be a good communicator.

What is the role of a communicator?

The foremost important role of communicators and journalists is to make available information and evidence to inform the public about issues that matter to them in the most neutral way possible. ... They gather news, facts, and information that are critical to public life and well-being.