Study shows Japanese infants hear foreign words according to Japanese language rules by 14 months

A new study on Japanese and French infants by researchers at the RIKEN Brain Science Institute and their collaborators has provided first-ever clues on the development of mechanisms governing how people perceive the words of a foreign language. The findings show that by only 14 months old, Japanese infants are unable to distinguish between words with sound sequences foreign to the Japanese ear, suggesting they have tuned their perception to how sounds are sequenced in their native language before even learning its words or grammar.

The question of how infants learn to perceive and segment speech is central to our understanding of the origins and development of language. Studies have shown that young infants can already distinguish patterns common to their language from those that are not, but it is not clear how this capacity relates to the highly-tuned perception of speech known to occur in adults.