I do both what aquinas describes and what ElizabethN describes, but it had never occurred to me to think of them as the same thing! I suppose this means I fill my buffer but typically also comprehend its contents as they go in. DS can also do both, I think, but often (as recently discussed) does not actually pay attention to an auditory stream directed at him if he's reading. I have sometimes reacted in annoyance to his claim not to have heard something he should have heard by telling him to replay it - I assumed he'd be able to do it and indeed he could.