Make sure you are not encouraging the behavior by nagging or making requests that you don't follow through on. If you typically repeat yourself three or four or twelve times before you take action, your child will learn that he can ignore you the first few times, because all he'll suffer is having to listen to the drone of your voice. As an example, say you want your child to get ready for bed. Use action instead of words. Instead of complaining about the pile of dirty socks in the family room, simply pick them up and hand them to your child.
Kids are remarkably perceptive when handed a wad of dirty laundry.
Have a doctor check your child's hearing to be sure there is not a physical problem preventing your child from hearing to you.