None. But I am great at public speaking and articulate well.
Life! Seriously I have no direct training but you can not teach personality and imagination. They are conditioned habits and are pulled from life experiences.
I think most of your best performers have a natural talent and confidence that comes through in their voice... right?
I own none, however I have multiple friends with in home studios that work with local original musicians. They have fully equipped studios and can accommodate all your needs. I recently owned a 14000 sq foot live music venue for 7 years and have great ties in the business here in Philly.
I am a 46 year old white male with a positive outlook on life. I live with an attitude of gratitude and am very confident. I have fun sarcastic personality.