Call those people or visit in person if possible. Still others get the message through doing, you need to walk them through it. As you can see, there are as many ways of processing information as there are people. You need to experiment until you find the way that works. A quick shortcut in this process is to mirror what they do.
Chances are pretty good that that is the best way to communicate with that person.
In short be flexible and aware of your audience. That leads into the next point, effective listening. As we've hinted throughout this article, good listening skills are crucial to good communication. Good listening begins by giving the person your full attention. If you try to do two things at once, both of them will suffer.