I don't subvocalize when I'm reading a narrative account, and my readings speed is 800-1200wpm. When I read poetry, textbooks on unfamiliar subjects, or in a non-native language, I do subvocalize and my reading speed is reduced to approx. 600-700wpm.
When I stop subvocalizing, the narrative turns into action in my head. I don't know what words I'm reading, but I see the characters playing out the actions the text describes. It's more like a dream than a movie, in that the images are not well fleshed out, and I only see what I am focusing on. Sometimes, I can see/feel concepts interacting, which is harder to describe but feels almost like a slightly psychedelic experience, as if I am absorbing the meaning without the medium. Reading like that is an actively pleasurable experience for me that is both meditative and exciting.
I have this experience when I read and really get immersed. I have the feeling that a noticeable or persistent voice in my head is more of a symptom or signal of my distractedness than the cause.
Also, how did you measure your reading speed, is your comprehension good at the upper end, and did you do anything to purposefully increase the reading speed?
http://en.wikipedia.org/wiki/Subvocalization
I'm curious about how often or to what degree visitors to this site subvocalize as they read. I was originally interested in reducing subvocalizations as a way to increase reading speed, as the idea is mentioned in multiple pieces I've read about speed reading.
The Wikipedia entry seems to focus on subtle throat and muscle movements, but I'm more interested to know if you "say" or "hear" the words in your head as you read.
Since reading about subvocalization recently, I seem to notice that I "say/hear" what I'm reading quite frequently. I'm not sure if this is causal (in the way that the command "don't think of pink elephants" obliges you to do so), or if I just notice it more now, or both.
When I'm very engrossed in a book either I don't notice the subvocalizations or they stop happening, so seems that it could either be a cause or a symptom of distractedness.
In the comments, please describe your mental subvocalizations (or lack of them) and if they are related to how engrossed you are in the book. Any other comments relevant comments about speed reading or subvocalizations are welcome.