Development of phonemic distinction in Japanese preschool children.

The literature suggests that, within several months of birth, infants develop the ability to distinguish between different speech sounds. However, the time frame for discrimination of a specific phonological system remains unclear. In order to clarify this, the discrimination responses of 211 preschool children were examined. The test battery consisted of 16 pairs of Japanese words, of which each pair contained distinctive phonemes in the initial syllables only. Test stimuli were presented in 2 ways: one as a whole test word and the other as only the initial syllable, which contained the target phoneme. When the test stimuli were whole words, correct discrimination exceeded 60% for test pairs in age groups older than 2:06-2:11 chronological age (years:months). However, when initial syllables were used, correct discrimination only exceeded 60% in age groups older than 3:06-3:11. Phonemic distinction within syllables seems to be established during early preschool age in Japanese children.