Half Life 2 - Overwatch voice
Channel: nomen nesco
Date: 2011-04-26

The Overwatch Voice (acted by Ellen McLain) sometimes simply referred to as Overwatch in-game, speaks to the Civil Protection units via their communication radios and to everyone in a particular area via local PA systems (in City 17, Nova Prospekt and the interiors of the Citadel). She will usually issue warnings of resistance infiltration or instructions to nearby units in a distinctive flat, clinical tone. Her disjointed speech, similar to that of telephone banking systems, and ability to apparently broadcast to more than one location at once suggests that she is an artificially intelligent computer system.
Her role, while small, offers significant insight into the inner workings of the Combine, as she uses a type of medically-inspired Newspeak to describe resistance activity in the context of a bacterial infection and treatment. Some of her announcements also display the coercive and violent tactics used by the Combine to ensure conformity. Parallels can be drawn between the Overwatch Voice and the telescreen news announcer in the 1984 film version of Nineteen Eighty-Four, who serves a similar role and is somewhat similar to the Overwatch Voice in terms of voice. There are also similarities with the MFP dispatcher from the film Mad Max.

http://half-life.wikia.com/wiki/Overwatch_Voice