I think maybe we missed the boat on this, but wondering if anyone has started baby sign language after 1 year and still had success?

My DS is 15 months and because of constant ear infections and fluid issues he couldn't hear very well until pretty recently. Because of that, he still only has a few words (dada, baba for milk, bubble, tickle, MINE) and most aren't helpful with everyday life!

He gets SOOOO frustrated that we don't know what he wants and just ends up screaming / crying pretty frequently. I know this is normal for this age, but I'm wondering if he could learn signs like HUNGRY / food, sleep , etc. if it would help our day to day. He does know the sign for "more" but he learned it when he was like 7 months old!