I subvocalize... and I know from speed reading course this is the deadly sin.
Well in PR they don't deal with it. If you see the description of dipping you see you're supposed to go fast, really fast. You're to eat up whole ideas at a glance, not those little words.
I would suggest that if you Need to beat subvocalization, then relax and don't worry about it. You should make your goal to dip properly and not to get rid of subvocalization. It will happen naturally if you reach your goal.
There are other subvocalization threads, on the forum. I believe AlexK response is to read for 30 minutes and chant the entire time. At the end of the 30 minutes you will have stopped subvocalization. I personally have only lasted a few minutes at it. However, I don't doubt Alexk. Maybe I'll try again. I know I have read without subvocalization in the past and it's a blast.
Good luck, and have fun.
Iam2