Reading aloud involves a continuously repeated series of steps. The reader receives visual stimuli (printing on a page or screen), deciphers the words and phrases represented by the stimuli, determines how to say them, says them, hears himself say them, perhaps also sees or hears the audience's reaction to what he's said, and adds what he's heard himself say (and possibly the audience's reaction) to his determination of how to say the words and phrases that come next. On top of all that, by the time he's saying one set of words, he's already beginning to digest the next set.
The psychologist Egon Brunswik devised a model for our processes of perceiving and acting that (in the way social scientists have of describing things) cloaks a familiar experience with rather unseethroughable terminology. In simplified terms, at one end of the model sits the "distal stimulus," such as words printed on a page. The distal stimulus emits "proximal cues" (such as reflected light waves) from which the "organism" (i.e., you or I) selects those cues that are relevant for the organism's present purpose (some marks on a page are relevant to reading aloud, while others, such as finger smudges, are not). From the selected cues, the organism derives an ultimate perception, or "percept" (e.g., the idea that the next phrase to be read is "great, Monadnock hump"). Then there is an "action" process that works somewhat in reverse. It begins inside the organism, with a "central motivational state," on the basis of which the organism chooses "proximal means" to achieve a "distal end."
Depending on your habits of mind, that last paragraph is either helpful or ridiculous. If you're a mental plodder like me, you might be thankful to have handles for the different things that go on when we read aloud. Reading aloud demands the execution of impressively complex behavior, since the reader steadily takes in printing -- proximal cues from a stream of distal stimuli -- while simultaneously producing comprehensible speech -- harnessing proximal means to reach his distal ends.
Given everything that has to happen, most of it inside the reader's head, for someone to read out loud, determining why someone has difficulty reading well is nigh impossible. But I'll venture to say that many marathon readers who perform poorly do so largely because they pressure themselves to read faster than they comfortably can.
All of which leads me to the third principle in our continuing series:
Rule 3: Read at a pace that is comfortable for you, even if it seems too slow.
When a reader pushes herself to read as fast as she can, or faster, two things happen. First, the phrases come out in disjointed spurts. A familiar clause comes out at breakneck speed, then a difficult word or two is stumbled over, then some more familiar words are rushed through, and so on, with phrasing dictated not by Melville's meaning, but by how easy or hard the language is. Second, the reader makes far more mistakes than he otherwise would, prompting constant self-correction as a word is misconstrued, the error is caught, and the word is repeated.
No one expects the text to be read quickly. We're not in a rush to find out what happens in the end; we all know that Darth Vader is Ishmael's father. We listen because we love how Melville wrote. We want to enjoy his artistry. What most of the audience would prefer, therefore, is a smooth, steady reading, at a lazy, conversational pace. In all the hours I've spent listening to marathon readers, I can think of only one who struck me as reading too slowly. And even he was not annoyingly slow. On the other hand, many many readers read (or try to read) too fast.