There's an instrument in most doctors' offices, I'm not sure what its called, but it sends a pulse through the ear and measures vibrations of the middle ear membrane. I strongly urge you to have your doc check your son's ears this way, if he can. Its a non-invasive way of checking the maturity of the inner ear tubes, I think. Both of my older sons' ears "flatlined"--no vibration at all. Josh was constantly sick with recurring ear infections due to immature tubes. David was almost never sick, but it turned out he was almost completely deaf. They both have surgically implanted tubes now and they haven't had a single ear infection since, with the added bonus that they can now hear when I'm bossing them around. Surgery should never be the first solution, but if your doc checks the status of your son's ears this way at least you'll know if a consult with an ENT is in order.
God bless Dr. Anthony Chebli, our wonderful family doctor who died suddenly this past spring at the age of 52. My sons can hear because of him. Wonderful, wonderful man. sniff
Thanks, I'll mention that to Dr. Barbara next time we're in for something. James can obviously hear (He says "Hiya" "Daddy" and "Brother"), but any time we can rule out a potential problem, that's good!