Baby signing sheds light on babbling

Babies with normal hearing but deaf parents "babble" with their hands, supporting the notion that vocal babbling reflects attempts to use the natural rhythms of language, researchers say.

While parents might strain to hear words in baby babble, some researchers have suggested it is unrelated to language and just the result of moving the mouth and jaw. Others say it reflects babies' sensitivity to specific patterns of human language and their ability to use them. The new work supports this second idea.

Scientists studied three hearing babies of profoundly deaf parents and three other babies regularly exposed to spoken language.

Analysis found that the babies of deaf parents, in addition to showing hand movements like those of the other babies, also tended to produce a kind of movement that resembled signing.

That shows the babies were picking up the specific rhythmic patterns that underlie human language, wrote the researchers, from McGill University in Montreal, Quebec, and elsewhere, in the Sept. 6 issue of the journal Nature.