SINGAPORE - Babies exposed to two languages at the same time learn the rules of each language faster than monolingual babies, a new study by psychologists has found.
They are able to detect tone changes in Mandarin speech at one year of age, using a method that tracks the time they spent looking at the word object on a computer screen.
They spent double the time looking at the syllable "ba" presented to them in Mandarin speech in different tones, compared to an almost equal amount of time when they looked at the same syllable in English.
More fixation time reflects the babies' surprised response when the tone changes, indicating a sensitivity to the differences, said Associate Professor Leher Singh from the department of psychology at the National University of Singapore, the lead author of the study.
In comparison, babies who were only exposed to Mandarin were less sensitive to tone changes.
They only showed similar results to one-year-old bilingual babies in being able to grasp tone differences when listening to Mandarin speech when they were 18 months old.
The year-long study, which involved 72 babies, was completed in 2015.
It was conducted by Prof Singh, Ms Charlene Fu, a PhD student and Ms Felicia Poh, a research assistant.
Their study was published in the journal Frontiers in Psychology in April this year.
"Our results dispel commonly held beliefs about bilinguals being slower in learning words," said Prof Singh. "Parents need not worry that learning English will take away a child's potential to learn Mandarin as learning both languages may strengthen their knowledge of Mandarin."
In fact, bilingual babies have a six-month head start compared to their monolingual peers, and they can negotiate the rules of different languages quite successfully, she added.