How to get help for 3 year old with speech apraxia? Getting the brush off!?

My Nephew is just 3 years old (born June 2006), and we joke about his "foreign language". But it's not funny, he gets frustrated because we don't understand him. He uses two word sentances most of the time because he is aware of the problem. We patiently listen and repeat what he said, but he'll say "no" but repeat the same word again. We try to guess similar words because sometimes he repeats a sound when it should change, or visa, versa. He kept saying what sounded like "teacher", we guessed t-shirt, picture. Each time he would say the same thing. When we say exactly what he says, he'll say "no".

As if to make it all the more frustrating, the Birth to 3 and Pediatrician are brushing it off and saying to give him more time, speech developes at different rates, don't compare your other son.

I know they are wrong, but don't know who to go to. We live in North central Connecticut, near Springfield, Massachusetts. Any experience or ideas of where to go next?