- News Home
5 December 2013 11:26 am ,
Vol. 342 ,
Dyslexia, a learning disability that hinders reading, hasn't been associated with deficits in vision, hearing, or...
Exotic, elusive, and dangerous, snakes have fascinated humankind for millennia. They can be hard to find, yet their...
Researchers have sequenced and analyzed the first two snake genomes, which represent two evolutionary extremes. The...
Snake venoms are remarkably complex mixtures that can stun or kill prey within minutes. But more and more researchers...
At age 30, Dutch biologist Freek Vonk has built up a respectable career as a snake scientist. But in his home country,...
Since arriving on the island of Guam in the 1940s, the brown tree snake ( Boiga irregularis ) has extirpated native...
An animal rights group known as the Nonhuman Rights Project filed lawsuits in three New York courts this week in an...
Researchers have been hot on the trail of the elusive Denisovans, a type of ancient human known only by their DNA and...
- 5 December 2013 11:26 am , Vol. 342 , #6163
- About Us
Tutoring With Baby Talk
31 July 1997 7:00 pm
The singsong speech adults use when talking to infants seems to get a baby's attention and even bring a smile. But a report published in today's issue of Science* suggests that this "parentese" may be more than just a tool of endearment. It can, the researchers propose, help infants learn the key features of vowel sounds.
Adult speech is far from uniform, with countless subtle variations on each sound, such as the "a" in "cat" or the "o" in "cot." As children learn language, they must master which phonetic differences to pay attention to, and which to ignore. In earlier work, Patricia Kuhl of the University of Washington, Seattle, and her co-workers found that by 6 months of age, Swedish and American babies learn to categorize vowel sounds, paying attention to meaningful distinctions, while ignoring other variations. Now Kuhl has probed further by studying the parentese of three different languages--English, Swedish, and Russian--to see if the distorted tones provide cues that may be useful for vowel pronunciation.
The team focused on formants, the resonant frequencies that, like notes in a musical chord, make up each vowel sound. If vowel sounds are plotted on a graph, with the frequencies of the two dominant formants represented on the x and y axes, the result is a "vowel triangle," with the sounds "ah," "ee," and "oo" at the corners. Kuhl's group found that, in all three languages, mothers talking to their babies produced exaggerated versions of vowels, emphasizing the features that distinguish them from each other. This nearly doubled the area of the vowel triangle. "It looks like the mothers are increasing the value of the signal," says Kuhl.
The mothers' speech also provided many examples of each vowel sound. This, Kuhl proposes, may help babies learn the features that make each sound special and to ignore the phonetic variations that fall within a given vowel sound. Indeed, by 20 weeks of age, babies' babbling contains distinct vowel sounds that form their own--albeit higher pitched--vowel triangle.
The work "illustrates a close tie between the input and what the child is doing," says language researcher Peter Jusczyk, of Johns Hopkins University. He cautions, however, that it hasn't quite proven that parentese serves an instructive role. "The fact that parents do it doesn't necessarily mean that it is essential for language learning," adds Stanford developmental psychologist Anne Fernald. That hypothesis might be tested, she says, with studies across cultures that use different amounts or types of parentese.