Consider homeschooling if at all possible. Get him out of the "normal" dayschool setting, it is probably making the situation worse. DON'T put him on meds unless he is a severe case with no other options, which does not sound like the case for you.
Auditory processing disorder runs in our family, and we were told one of our sons probably has it mildly as well. (From the research I have done, I agree...) He has improved as he gets older, but I could go on and on about the funny quirks and challenges we have faced with him, even though he is a very easy kid to discipline and extremely bright as well, and it really hasn't been all that hard.......just worrisome at times for us. But we do call him our "Wiggly Willy", after a learning style we read about in a homeschooling resource book. And my husband has always been a "Wiggly Willy" too, and is now an amazing youth sports coach, because of his active, always on the go personality, he really understands kids :) People would have considered both of them ADHD if we sought a diagnosis, but since it hasn't led to any discipline issues for our son, it really hasn't been necessary.
Our son was in private preschool at our church, homeschooled him for Pre-K, and he is now in public school for K. He does incredibly well in class (the school called to let us know they wanted him to skip a grade, but we said no). BUT, I have seen his attention span and behavior change SO MUCH for the WORSE in just the few months we have had him in public school instead of homeschooling! He is learning really bad habits from all the other kids in his class. He is learning that "no" doesn't always mean "no", and if no one is looking, you can just keep doing what you were doing until they really tell you to stop. He no longer listens to directions from me on the first go, because he just kind of has to do his own thing at school, while the other kids are goofing off and not listening to the teacher at all. He is learning how to talk out of turn and interrupt until he is heard, instead of waiting or saying "Excuse Me", because this is how things are at school, the loudest one "wins" in public school.
All the things we worked so hard with him, listening habits and manners, are going out the door each day because of the way public school "works". They have him for more hours each day than we do.
Anyway, all to say, that for a kid who already has some ADHD type personality traits, and tends to be hard to focus, having him in public school is making it much much worse than it ever was. And if at all possible for us next year, he will be homeschooled again. (I had to take a break this year for health reasons.) He learns so much more at home, and the attention issues are hardly an issue. Not to mention, he gets to eat healthier too. It's a lot easier to serve more of a variety of healthy foods, when it isn't something that has to stay cold in a lunchbox. Which of course, diet plays a huge role in any kids' ability to focus!
Hope that helps.
If you have any questions about homeschooling, I can refer you to some wonderful people / resources.
Also, research sensory integration disorder on the web if you haven't already....both my kids have issues (the one with auditory, the other with touch and taste, definitely runs in families). It helps to be aware of it, not cater to it, just be sensitive to it.
Tara