The Black Mesa Announcement System is the public address system used throughout the Black Mesa Research Facility, relaying audible messages and announcements across the facility with a male voice. Additionally, a similar announcement system is mounted on trams to give general information about the facility and mention each stop, with a prerecorded female voice. Judging from its mechanical voice and fragmented, disjointed speech, it is probably a basic AI, similar to the Overwatch Voice.