If you are concerned talk to your ped. There should be milestones at a certain age that your son should be reaching. At each visit with my child, the dr. asks is she or he doing this, or what about that. They should be doing this. If he is getting ear infections alot it might be affecting his hearing so he isn't able to pick up the sounds of words to learn how to say them. Some parents will give their child whatever they point to and not make them say it or ask. Are you guys asking him what he wants by making him try to say it. If he can't say the things, what we do with my daughter is say do you want than say the word to her a couple of times, we don't just let her point than give it to her. She wouldn't have the need to learn how to talk than. My mom told me my brother was a late talker since he had a bigger sister that would give him everything he pointed at. My friend has a two year old son and he wasn't talking much either. The took him to the dr and ran a bunch of tests, one being hearing. They came to the conclusion that he needed to go see a speach therapist. But if you are concerned talk to the child's doctor.
As long as he's understanding and responding to things you say to him then you could just have a slow talker on your hands. I remember some kids(usually the boys) I worked with couldnt/wouldnt talk much for the first couple of years but when they did begin, it poured out of them like they had been doing it all along. Tell your child's doctor your concerns too.