Delayed Speech and Language in a Two Year Old
I'm glad you're getting his hearing checked, even though he seems to hear well. At his age, an audiologist with experience in pediatric assessment should be able to interest him in some hearing ''games'' such that the results will be quite accurate. Sometimes, depending on the child's mood, sleepiness/hunger factor, or anxiety about strangers, a second test will be needed to get a complete assessment. Other than that, you'll know very shortly whether your child hears normally or not.
The second part of your question is a little more complicated. It is indeed possible that your child hears ''differently'' from others. Some obvious reasons for this would include a history of repeated ear infections, which can cause sounds to be ''muffled'' at times. Children learn how to speak from listening to others...if your son has had a fluctuating hearing loss as ear infections or ear ''fluid'' came and went, he has not had a consistent model on which to base his own speech.
A family history of ''late talking'' can be significant as well. At what age did you and your son's father start talking? Do you have any other children, and if so, what was their pattern of speech development? Is there a history of learning disabilities on either side of the family?
Another complicating factor can be if more than one language is spoken in the home. Although it is much easier for children to learn both languages while they are young, it is also sometimes true that hearing two different language models concurrently can delay speech production in some children.
Lastly, keep in mind that children develop at varying rates. Some children naturally develop motor skills before language skills, learning to ride a tricycle or grasp and manipulate small objects early. Other are precocious talkers. By the time they reach kindergarten, the the kids with great motor skills have usually caught up in language, and the talkers have honed their motor development. Make sure your expectations for his speech and language development are on target. He should be using two to three word phrases by now, like ''mommy, come'' or ''I do it.'' He should understand much more than he can say, and should be able to follow directions like ''go to your room and bring Mommy your shoes.'' On the other hand, many of his speech sounds will not be accurate at his age. Sounds like ''m,'' ''b,'' ''d,'' and ''g'' should be clear, but many more difficult sounds like ''sh,'' ''j,'' and ''r'' may not be pronounced with complete accuracy for several more years. Ask your audiologist or pediatrician for a good handout on normal speech and language development by age.
In summary, you are doing the right thing by getting your son checked. Be sure to choose experienced professionals and follow up on their recommendations and referrals. In the end, if a problem is detected, it will pay off to start treating it early. If it turns out your son is just a ''late talker,'' the evaluations will have been worth it just to put your mind at ease.