The Verge has an awesome post about two individuals — friends actually — who you may recognize due to their voice. They are Carolyn Hopkins and Jack Fox, two individuals who are the voices used in automated paging systems in over 110 airports as well as the NYC Subway system.
They were both asked by Innovative Electronic Design (IED) to lend their voices to warning messages, public announcements, and transit instructions and their success is due largely to their ability to make their voices sound friendly yet commanding.
The Verge post has an audio interview with both of them that I highly recommend listening to. It’ll mess with your head! Check it out!