My DS reads silently just fine and has a very high comprehension.
However, like many here have mentioned, he skips words. He changes verb tense. He even paraphrases as he reads aloud. It's almost like his brain is reading far ahead of his mouth so much so that by the time his mouth catches up, he's already sorted out unimportant words and paraphrased, while still maintaining enough content to comprehend.
Does your library have a Paws program where kids can read to a therapy dog? It's a non-judgmental reading exercise because the dog doesn't judge and sits or lays quietly and listens. If you have a pet, you could have him or her read to it also. I do think this is a skill, like any other, that sometimes needs work to perfect. (There are plenty lectors at my church that skip words or change them (completely changing context), so it's not just kids who might need practice!)
Also, I would note, too, that cadence while reading in your head is definitely different then reading aloud. If you are a fast reader, you might not pause too long at the end of a sentence, but if you're forced to read aloud, you do need to do that.
Good luck! My son hates to read out loud, so if we do read from a book or short story assigned as homework, I have him read one page and I read the other.
