Parents learn over time to interpret the cries of their babies, differentiating between hunger, pain and just plain fussiness.
But how do deaf mothers and fathers decipher their babies' whimperings?
Now, thanks to a new app, hearing-impaired parents can tell when their infant is wailing and determine what is most likely the problem.
Dad Delbert Whetter and his wife, Sanaz, had equipped their home with cameras and sound monitors, but, "We can only tell if there is something loud happening in the room," he said. "We have a child that is very talkative. He would babble. So we can't distinguish between loud noises and crying."
The ChatterBaby app, developed by Dr. Ariana Anderson at the UCLA Medical Center and Semel Institute, uses sound frequencies and patterns of silence to interpret what a baby is crying about.
Anderson stumbled upon the idea after the birth of her third child, when she noticed the similarities in all her children's crying.
"As a statistician, I see the world in terms of numbers and patterns, and so the first thought was whether or not I could train a computer algorithm to do what my ears as a parent could automatically do," she said.
She compiled a database of more than 2,000 infant cries and used machine training to translate what the cries mean. For example, is the baby fussy, hungry or in pain?
"Between fussy and hungry, it's a little bit hard to tell. But pain we could identify with nearly 90 percent accuracy," she said. If a cry has a long period of silence between wails, it's like the baby is fussy, she said. Constant, high-pitched screams usually mean something hurts.
After helping to test the app, the Whetters said they wanted the device in their home. "We can't have eyes everywhere, so that would be really nice to have," Delbert said.
His wife added, "I hope the app will help more than just the deaf community but hearing people, too."