Not sure about this, but ds is 13 months (and a half) and he has hardly got any words.
He can say Mama, which has only just crossed over from 'sound I can make' to 'word with meaning' iykwim,
he can say 'check' but doesn't know what it means, he was just repeating it.
He can say bot-bot when I change his nappy.
That's about it.
Is this normal? A quick google suggests he is a bit behind.
I think his hearing is Ok as he babbles a lot and dances to music and gives us a monologue now and again, well every day, of different random sounds he can make.
Just not sure if he is in line with average. He also doesn't seem to understand 'no' or maybe he is just ignoring it 
Thanks