San Diego mom Monta Briant is hands-on when talking with her son, Aiden.
Since birth, she's been teaching him American sign language, even though his hearing is intact.
"Even at only 3 weeks old, if he saw me sign the sign for milk, he would actually start crying. He knew exactly what it meant very, very early on," Briant said.
The concept is based on years of research by Dr. Joseph Garcia, who founded the "Sign With Your Baby" system. It's a program used by certified instructors teaching parents and babies ASL across the country.
"Signing is different than verbal language in that there's an eye connection. You must look at someone when you're signing to them," Garcia said.
Most babies can begin learning ASL at about 6 to 8 months, he said. Along with signs, they learn the importance of eye contact, and how how to stop, look and listen.
At 18 months old, Aiden now knows how to sign more than 150 words, allowing him to manually communicate what he can't say, Briant said.
"Really, a baby's brain is capable. They're capable of communicating by signing long before they can talk," said Briant.
The more signs babies learn, the more it could reduce those tantrums that come with the "terrible twos" -- they're not as frustrated with communicating what's on their minds, Garcia said.
Parent-to-baby signers say that the three easiest signs with which to start are eat, more and milk. Most parents add the gestures when speaking to their babies and over time, the baby learns to use it, too.
But be patient -- it could take weeks or even months for younger babies to sign back.
Does gesturing delay speech development? It's a common concern brought up to speech pathologists at Children's Hospital in San Diego.
"(You should say) the word as you're signing the word. What we've found is that children will actually start speaking sooner when you pair both the gesture and the word. And typically once they have the verbal words, they'll drop the sign out," said Dr. Sharri Garrett.
Briant loved baby signing so much, she's now made a business out of it, offering special playgroups. She published a book for parents called "Baby Sign Language Basics" with easy instructions on how to gesture 60 popular words.
Parents say the process is not only fun, but it allows them to connect with their baby in ways they never thought possible.
"Communication with your child is so much easier and better, and just being able to interact with them (is) absolutely wonderful," said signing parent Suzanne Morrow.
ABC affiliate KGTV in San Diego reported this story.