First of all, if you don’t have (or haven’t read) James Alburger’s book “The Art of Voice Acting,” get it, and read it. There is so much great information in it, from vocal warmups and voiceover techniques to script analysis and finding the character in the copy to demo and business advice. Highly comprehensive!
Here’s James’ crazy cork exercise to strengthen muscles and improve your articulation and enunciation:
— First record yourself reading a few lines of text from a book, magazine, article, etc.
— Then place a cork in your mouth lengthwise so that it resembles a cigar, about 1/4 inch behind your front teeth.
— Read those same lines out loud from with the cork in your mouth. Speak slowly and distinctly, being careful not to drop the ends of words. Your jaw and tongue will likely begin to get tired rather quickly.
— Now turn the recorder back on and record yourself reading the copy one more time. Play back both recordings, and you should notice a big difference in the sound of your voice, with the after version being much cleaner and easier to listen to.