Awaiting the Chatter

We have had a few therapists and people in Roa's world ask about his communication skills lately.  Roa is almost 17 months. 
A typical developing child at his age would have 5-10 words that he could use confidently to communicate. Mama, Dada, Up, No, Cup, Truck, Ball, More.... all typical firsts. 

Roa does not use words yet.  Does he understand language?  Very much so!!  Roa knows many words- get your blanket, ball, outside, butterfly, walk, where are your socks/shoes, Mom, Dad, all his pets, airplane, all his therapists, juice, milk, Elmo....
But, he doesn't talk yet.  He yells, coos, laughs, babbles, screams, cries... but no consistent words.

Are we worried?  Yes, of course.  But, after years of teaching Early Childhood Special Needs, I know that it will come.  Give it time.  We are doing the various communication "bag o' trick" methods- language rich environment, talking about EVERYTHING to him, reading and naming objects in books, giving him choices of objects so he can communicate his desire, working on YES/NO questions and the head shake.  I am fluent in sign language and have signed to Roa to stimulate language since he was born! 
He does not nod yes or no yet.  He does not sign familiar words yet.
He listens intently.  He watches every sign we make.
And so we wait........ patiently.