It depends on what you mean by rambling.
Sometimes it can take a moment to hone in on what is actually required, especially if there's a sense of urgency in having to express myself. Otherwise I am usually economical with what it is I say.
If I remember to pause before answering, to get a sense of what should be said, there's no rambling. If I remember I don't need to say more than is necessary, there's no rambling. If I just speak without thinking, let words come out in a sort of stream of consciousness way, as if I'll get there eventually and hope my brain catches up at some point with my mouth, there could be rambling.
I really need to learn this pause thing.