Did you speak parentese to you kids when they were babies?
You know parentese, it's that high-pitched, extended vowels, often referred to as "baby talk." Parents do it naturally because it captures the babies' attention.
But Dr. Patricia Kuhl at the University of Washington who studies how children learn wanted to know if it does more than that.
So she equipped babies with wearable high-tech recording devices programmed to bookmark outbreaks of parentese, and the babies' responses.
"We recorded from these microphones for 24 hours a day for four days in a row," said Kuhl. "We wanted to know, are parents really using this language that we describe as parentese or motherese?"
Kuhl and her researchers asked, how do adults use parentese when talking to babies, and how are they doing it? Are they talking to babies one-on-one or in a group? And how is that linked to language at two years of age?
The babies really like listening to parentese, she says, and given the choice, they choose to listen to parentese over adult-directed speech - how we talk to each other everyday.
Studying kids 11 to 14 months old, Kuhl said children that age were often struggling with their first words. "We measured their concurrent meeting at the same time as their babbling, their attempts at words and speech and then we brought them back in at the age of two and remeasured language."
The kids that had one-on-one time with parents, and in particular, the kids whose parents had talked in parentese, knew twice as many words as kids that heard more adult-directed language.
"The numbers were huge the difference between 433 words mastered at the age of 2, compared to 169 from the highest to the lowest," said Kuhl.
It's not the first time Kuhl has researched how babies learn language. "We've been doing a lot of looking at how the baby brain is attracted to one-on-one interactions, social interactions with real people. We were the ones that showed, some years ago, that babies learn, that are exposed to a foreign language at nine months old - Mandarin in this case, learned it beautifully if they had a live human tutor playing with them on the floor. But if it came from a beautiful DVD they stared at, they learned nothing."
So, maybe part of the lesson here is, don't park your kid in front of "Sesame Street" and expect them to learn language.
"The message for parents, it's not so much the vocabulary, but it's how you introduce it that's crucial," said Kuhl. "I think vocabulary is important, but if parents were to do one thing - they should use parentese in a one-on-one context."
Dr. Kuhl's next study will use a brain-mapping machine to measure babies' responses to language in real time, in hopes of learning how to catch speech problems and treat autism more effectively.
MyNorthwest.com's Alyssa Kleven contributed to this report.