When my daughter was 4, her doctor had me put a hand on either side of her little face and hold them there gently until she would look me in the eye. If she looked away, I would stop talking, when she made eye contact I would start over. She learned to listen and focus on what I was saying. We only used this method for the more important stuff, eventually all we would have to say is look at me please while I am talking and then she tuned out whatever else was going on and would focus on us. Her teachers would tap on their desk, not saying anything, and that was my daughters sign to pay attention. No one else in the room knew it was just for her benefit...they thought it was meant for "all" who may not be paying attention.