I did all the announcements played on loop at my last workplace. They chose me because of my ability to make sarcastic announcements with a very clear and official sounding voice.
People I know constantly ask me to quote things for them, such as Gollum from lord of the rings, which is basically what leads me to believe I can be successful with this career.
Other than that and goofing around with audio at home, I haven't had much experience, and that's precisely what I'm looking for right now.
Being an avid Simpsons fan since I was little almost forced me to try and replicate characters on the show so I could reproduce hilarious quotes accurately for people. Most of my "training" is self-training by just spouting out cool quotes repeatedly after I hear them on tv or in video games.
However, I did take a workshop on voice acting at my community college from a well-off voice actor named Mike Elmore that basically showed me the ropes of the industry.
I work well with computers and technology; I'm musically inclined (I'm an ok singer) and play guitar.
People find I'm extremely competent and rarely ever compromise my responsibilities.