This study investigated how children learning Japanese utilize vowel length and pitch accent—both phonemic contrasts in Japanese—for word pair identification. Seven word pairs were used, differing in second-mora consonant and pitch accent (ˈumi sea vs uˈshi cow), second-mora consonant (iˈnu dog vs iˈsu chair), vowel length (ˈchizu map vs ˈchi:zu cheese; ˈbiru building vs ˈbi:ru beer), word-level pitch accent (ˈame rain vs aˈme candy; ˈhashi chopsticks vs haˈshi bridge), and particle pitch accent (haˈna+ˈwa nose + particle vs haˈna + wa flower + particle). Experiment 1 tested preschoolers (ages 3, 4, and 5) and first and second graders (n = 85). Results revealed that the particle pitch accent contrast yielded significantly lower accuracy across age groups (ps 0.05). Experiment 2 involved six-year-old preschoolers with pervasive developmental disorders (PDD) and typically developing (TD) age- and sex-matched peers (n = 14 each). PDD children had significantly lower accuracy than TD peers on word-level pitch accent and vowel length contrasts. Particle pitch accent accuracy was the lowest in both groups (ps 0.05). Identification of the consonantal contrasts (/ˈumi–uˈshi/ and /iˈnu–iˈsu/) was near-perfect in both experiments. These results suggest pitch accent and vowel length pose challenges in early Japanese acquisition, particularly for children with developmental disorders.
Ryoko Mugitani (Wed,) studied this question.