There is nothing quite like the cooing and babbling of a baby. Somehow, when a baby coos, adults just want to coo right back.
And that is exactly how it should be, since that is how babies learn to talk, explained Anne Dunlea, Ph.D., a developmental psycholinguist at USC who has spent more than 10 years studying early childhood development.
"A child cannot learn language from a book, from the radio, from television, even from 'Sesame Street,' " Dunlea said. "The way you learn language is by having someone talk to you at your level."
Parents, she said, do this almost naturally, changing their tone of voice to a higher pitch and amplifying on the language to appeal to a baby's sense of rhythm.
By videotaping infants and their reactions to language and sounds, Dunlea said, she found that infants respond rhythmically to language, moving their arms and feet to the cadence of the speech but not to individual words or noises.
She said scientists know that babies can hear in the womb, but they do not know what is heard. Within three days of birth, Dunlea said, infants recognize their mother's voice.
"We don't know if it is just quick training or if they recognize it from the womb," she said.
During the first few months of life, all the muscles, including the mouth muscles, are developing. And just as other muscles must be strengthened and developed through use, so must the muscles that make speech possible.
"It is important to exercise that muscle," Dunlea said. "That is why babies coo first, then make a range of sound. Babies will try out all human sounds, no matter what language they will eventually speak."
Hearing others repeat their sounds is positive feedback that encourages infants to try again, thus developing language skills. Even deaf babies babble during the first six months of life, although they soon stop because they do not hear themselves or others and do not get that important reinforcement, she said.
Infancy, she noted, is the busiest period of childhood development. Dunlea, who is a research associate at USC's department of linguistics, said children learn language remarkably quickly and are usually fluent speakers by age five.
"The emergence of language is important because it is a reflection of the child's mind," said Dunlea. "It enables the child to interact with others and it provides the child with a crucial key to other knowledge."
Because infants have the capability of making all the sounds used in any language (a skill that is later lost), Dunlea said, it is easier to teach children foreign languages at a very young age. Although the child may at first interchange words from the two languages, eventually the child will sort it all out. But trying to teach your baby a foreign language in bits and pieces will not work.
"They must be exposed to the language in a meaningful way, by a fluent speaker, so it interacts with the child's world," she explained. "You have to live the language to learn it.
Quality of Talk
"Talking to your child is the most important thing (in language development)," she advised. "The quality of a mother's talking is what is important in school success."
But, she warned, "let your child lead you. Always take it one step beyond where your child is now, but only one step." Pushing children to learn more than they are cognitively able to frustrates both the child and the parents and can really hamper learning.
Although speaking to a child is probably the most important step in learning language, Dunlea said, children do not mimic a parent's speech.
"No parent says, 'Me no go bed,' but that is how a child might express not wanting to go to sleep," she said. "A child's errors are very clever and reasoned."
Seven years ago, Dunlea and associates Elaine Andersen of USC and Linda Kekelis, who is now at UC Berkeley, developed a theory that language development is very dependent on a child's knowledge of the world, and on the child's ability to visualize things and apply words to different ideas. With grants from the National Science Foundation and the Spenser Foundation, they set out to test their theory, studying youngsters eight to nine months old.
Comparing children who were blind, partially sighted and sighted, the researchers wanted to know if sight made a difference in learning to talk. Dunlea said she was surprised to find that vision had such a profound effect on language development.
"The results surprised even me, and I went in thinking that sight did make a difference in learning language," she said.
A lack of vision, she found, prevents a child from applying what he has seen to other concepts. It hampers the child's conceptual and symbolic thinking.
"Blind children don't use toys the same way as sighted children do," she explained. "They are very specific about the words they learn. They are not as creative with expression (as sighted children are)."