Originally Posted by Gemini
Split stepping is only the instance of a single squeak which I'm not referring to. I'm talking about someone shuffling their feet multiple times (back and forth usually) while a person is somewhere in the process of serving prior to striking the ball. Capriati did this years ago and I've seen the occasional junior player do it once they realize that it can be annoying. If your shoes squeak when your recovery after a shot, there's nothing wrong with that.
I've seen the purposely squeaking while you are trying to serve thing. When a person does it, it's pretty clear that they are shuffling thier feet on purpose o make noise to distract you. That's pretty bush-league and I"m pretty sure you can call a hinderance on it. I had a friend who did that during our friendly matches as a joke. It never bothered me enough to affect me.
Out side of that, it would be pretty hard to call anyone on that sort of thing during a point since it may be hard to distinguish choppy footwork with intentional noise-making.