Researchers find mothers change the timbre of their voice for infants, but the “language” is still the same.
No matter what language a new mother speaks, odds are she’s fluent in “baby talk.”
A team from Princeton University found that new mothers shift the timbre of their voice to communicate with their infants, even across multiple languages.
“Timbre is best defined as the unique quality of a sound,” Elise Piazza, a postdoctoral research associate with the Princeton Neuroscience Institute and lead author of the study, said in a statement. “Barry White’s silky voice sounds different from Tom Waits’ gravelly one — even if they’re both singing the same note.”
Piazza and other researchers looked at how 24 mothers and their babies interacted. Half of the women were English speakers. The other 12 spoke a variety of nine other languages, including Mandarin, Russian, Polish, and French.
The team recorded the mother-child pairs as they interacted to see how their voices changed. They used a special device that classified the different timbres.
They found that the mothers’ voices changed in a similar manner.
The researchers also found that the timbre changes were so comparable that a computer algorithm could detect in most cases when a mom was talking to her baby or to an adult.
“Thus, shifts in timbre between adult-directed and infant-directed speech may represent a universal form of communication that mothers implicitly use to engage their babies and support their language learning,” Piazza said in a statement.
Dr. Jonathan Fanaroff, a neonatologist and the director of Rainbow Center for Pediatric Ethics at UH Cleveland Medical Center, said the the evidence that “baby talk” is universal is a new idea and sheds new light on parent-child interactions.
“Language and auditory communication is extremely important for a baby’s development,” he said.
He explained that doctors have long known that babies instinctively react to their mother’s voice. Talking and singing to babies can help soothe them and help them learn.
“Certainly, there are recommendations for parents to talk directly to the babies and sing,” he said. “It’s very important not only for sort of their cognitive development for learning language and learning communication skills, but it’s also very soothing for babies.”
Fanaroff said that even newborns can sense a parent’s mood through their voice.
“Immediately and through timbre and tone, babies learn to read cues and know when someone is angry,” he said. “Even newborns — they recognize their parent’s voice and their mother’s voice compared to other adults.”
The American Academy of Pediatrics advises parents to talk to their babies from the start to help them learn vocabulary.
“Even before your baby can talk, back-and-forth conversation will help your baby learn the meaning of words and later be more ready to start school,” the AAP advises. “So, ask him questions and then answer them. Name and label what you see inside and outside your home.”
For Piazza and the other researchers, they hope they can expand their findings and look at how people might change their timbre in other situations.
“Our work also invites future explorations of how speakers adjust their timbre to accommodate a wide variety of audiences, such as political constituents, students and romantic partners,” she said in a statement.