At the PR seminar I was told you never really stop subvocalizing, you just quiet it down.
During SuperReading, you should be going so fast that you can't subvocalize. It should take about 5 seconds to super read a page. When you dip and rapidread, don't worry about it. After I've photoread a book and I'm rapidreading, I subvocalize almost everything, but since I'm going so fast, it sounds like I'm remembering hearing the words, and they come to me in 3-5 word chunks. It's pretty neat.
