20 month old - no speech, no babbling

My son is 20 months old. I am concerned that he may have a speech disorder, and would like to know if I it is possible to do a diagnosis at this age. How worried would you be about the following?

* First, he is clearly not deaf. Good "receptive" language. Clearly understands how our house runs, where things are.
* Much of the day he is quiet (no sounds).
* His verbal communication is grunts "eh, eh, eh"
* He does point. He has little other gestures (does not wave bye bye)
* He has no words.
* He does next to no babbling. He'll say "mamamamma" for about 10 minutes during the day.
* He does not call me/my husband "mama" nor "dada".

His older brother  - who is currently 3.5 years - spoke only about about 5-6 words when he was at this age. However, the lack of babbling and syllables by younger son has me concerned. Could it be Apraxia? Or Something else?

Can we get him to a speech language professional now? And if there is a long wait list, what are good things to do in the next month? We already, and have been, reading to him a ton. Empahsizing words, Naming things, constantly. Help please!

Thank you!!

[Loulou2u]

I would try and get him in to see a paediatrician as soon as you can and maybe they can figure something out or refer him to a specialist.  I wouldn't be too concerned he was just not saying any words, but the fact that he isn't doing much babbling is a little concerning.   Getting medical advice is the best advice I can give.  Good luck with everything.