Infants who interact with people who speak foreign languages may develop a better ability to perceive foreign language sounds, says a study in this week's Proceedings of the National Academy of Sciences.
In previous studies, it was found that infants can discern small sound differences -- for example, the distinction between "b" and "p" - in both their native and foreign languages. But that ability to distinguish sound differences that aren't meaningful to their native languages disappears in infants between 6 and 12 months of age.
This University of Washington study examined the effects of continued foreign language exposure on infants. For four weeks, 9-month-old infants from English-speaking homes were exposed to Mandarin Chinese.
One group of infants had daily interaction with Chinese-speaking people who read children's books to the infants or played with them. Other infants were exposed to the same Chinese-speaking people through audiovisual tapes or audio-only recordings, while other infants were exposed only to English-speaking people.
The infants were then tested on their ability to distinguish between two similar Chinese phonetic sounds that don't occur in English. Only the infants exposed to the live Chinese-speaking people could distinguish between the two sounds. The study results suggest that social interaction may play an important role in language learning, the authors write.