Aperture Science Announcer

The Aperture Science Announcer is the voice that wakes Chell from stasis and slightly later guides her through the old Test Chambers at the beginning of Portal 2. He sounds like a pre-recorded generic, enthusiastic male voice, and sounds slightly sped-up. He also announces other things, such as GLaDOS's activation, and telling people to get off of the Turret Redemption Lines.

Trivia

 * His recordings include classical music and a buzzer.