King of Jericho - I know about the deaf schools in NYC - done some work there in the past.
Anyway - sign language is always a great thing to teach babies - allows them to express themselves in simple terms (hungry, mommy, milk, etc) before they have the ability to use their voices to articulate themselves. My daughter started signing when she was about 7 months old, same with my two boys, but maybe a little later, like 9 months. And pretty much didn't have the terrible twos because they can tell us why theyre upset, sad, etc. instead of throwing a temper tantrum,
And always great having earlier language acquisition so I can teach them earlier that BMWs are the best cars out there!
