None. I'm a retired senior with a strong, convincing voice that gets attention.
I am currently active one day a week doing volunteer work for WTBBL, (Washington Talking Books and Brail Library) a Federal and State funded organization. I read articles from local newspapers, magazines, and other selected works, for broadcast over WTBBL's subscribed FM radio network. The initial broadcast and rebroadcasts can also be heard over the internet at prescribed times via the web site: WTBBL.org The internet offers an additional avenue of listening if one wishes to bypass the use of the freely provided FM receiver required to listen.
No formal training in voice. Have performed in a small number of plays over the years but never as a 'professional'.
iMac and Garageband
I have been a Technical Writer for over 50 years, having written policies, procedures, and engineering instructions for distribution to the work force of major companies. Such well written documents make certain that there are no misinterpretations in accomplishing the necessary tasks to get the desired result. I have also created brochures and advertising pamphlets using DeskTop publishing as created by Apple, Inc. for use on a Macintosh computer. I believe these acquired writing skills add a keen sense to what constitutes a successful voice-over script.