There is an interesting collection of MP3’s here.
These are student training sessions in the soundbooth. You can hear the direction and you can hear the students working on the copy. I find that when I am in class and worrying about my upcoming exercise I can’t really concentrate that well on the other students when they are in the booth. This is an easy way to listen and concentrate.
This is from a studio down in LA where Kate McLanaghan runs a school called Sound Advice. They also do demos.
Oh, and there are also several recordings featuring Nancy Cartwright, you know, Bart Simpson?