My parents noticed this and gave me a speed reading book. I incorporated each an every item on that book including the removal of subvocalization. It certainly gave returns right away, allowing me to consume books at a faster rate, but a huge cost.
Years later, I entered college as an engineering student. I noticed that when reading highly technical textbooks, and classes that required deep comprehension of text, I was much much slower that my classmates, or my comprehension level was much lower. Turns out, it was taking almost double the time for me to get through a section.
Really wished I didnt read the speed reading book now. I dont blame my parents at all, it was unfortunate that at nearly 40, i'm still trying to unlearn what that speed reading book taught me. I'm trying to re-learn subvocalication but its very very hard to 'slow' myself down. I've actually installed screen readers to replace subvocalization with some positive effect.
Fundamentally, speed reading through something is at odds with processing that information in a useful way. And therein lies the rub: I don't read something merely for the sake of reading it.
When I read novels, I enjoy losing myself daydreaming in another world, and savouring the emotions of the characters while thinking about how I would react in their shoes. When I read technical documentation I'm attemping to create or update mental models of technical concepts. When I read a friend's Facebook post I think about what, if any, response I will offer or how I would deal with their situation. When I read a message from my girlfriend I have to take time to understand and plan for whatever she's discussing or asking.
I'm honestly struggling to see the value in speed reading. I cannot think of why I would be reading something simply for the sake of reading it without further processing. More valuable would be learning ways to process information more efficiently, i.e. accurately and quickly.
There is also a tremendous value to watching an important lecture twice: the first time on fast-forward so that you understand the structure of the talk and the gist of the subject, and the second time on normal speed so that you can really get into the details. A lot of writing tries to give you an "overview" or "table of contents" to accomplish the same task, but when it's not there, skimming can be extremely useful.
When I read it in a normal app (Kindle), I appreciated the beauty of the language, the depth of the characters, and the intricate storyline so much more.
For business stuff, a similar problem occurred - I missed out on key points in emails, and was less creative in solutions. I'm not saying that this applies to everyone, but for me, reading slowly is more efficient.
The key is reading the right stuff more slowly, and not reading the wrong stuff at all.
Sometimes you don't need to fully process a text, just know where in it you can find answers for any questions you might have later. For example when reading technical documentation. Speed reading is great for that.
I never took a speed reading course or lesson, but I cannot recall ever having subvocalized. I find myself hitting 750 wpm on speed reading tests with decent comprehension. Not great, but decent.
To use a computing metaphor, I feel like I'm reading with two threads - one to take in all the words as quickly as possible, and a second one to pick the important ones out of the stream. The first thread is completely unconscious, to the point where if you ask me to find a specific word on a page of text, I can always pick it out within 2-3 seconds.
But I feel like a greyhound, itching to run at top speed. Reading fiction is a constant struggle to keep myself chained, forcing myself to imagine the scene playing out, when all I want to do is speed ahead to find out what happens next. It's like an internal war, and it gets worse at the climatic moments.
I've recently been contemplating a re-reading of LOTR, but feel so far away from the potential to immerse myself in the universe that I have not even given it a serious try. Virtually all of my consumption is rapid reading of relatively light fare that I can consume in a one or two sittings.
The introduction of digital means has not helped me (i.e. Kindle, Kindle App), as this increases my propensity for speed, and virtually the only novels which conform to my expectations are overly long novels (i.e. Neal Stephenson) which provide enough change of pace without any particularly deep or moving characters.
Frankly, I have no idea what to do either. I also feel like a greyhound on steroids, incapable of fictional engagement if it does not come at breakneck speed.
Funny thing, it was at english class that I actually started noticing it. The exercise was to read against the grain and find the hidden meaning. I didnt get it until I physically read out loud.