Adult and infant sensitivity to phonotactic features in spoken Japanese

Japanese speakers perceive an epenthetic vowel between consonants in words, reflecting an adaptation to Japanese phonotactics. However, there are some contexts in which CC (successive consonant) clusters are acceptable in Japanese speech. This study explored how Japanese speakers perceive phoneme sequences according to Japanese phonotactics. In Experiment 1, adults rated goodness of nonsense words with CV and CC sequences as exemplars of Japanese words. The adults were sensitive to the legitimacy of vowel devoicing. They considered phoneme sequences following the Japanese phonotactics to be better than exceptional but possible sequences. Experiment 2 investigated 6-, 12-, and 18-monthold infants’ sensitivity to phoneme changes in words. Infants of all age groups detected vowel changes (CVCC vs. CVCVCV) in vowel-devoicing contexts and only 18-month infants detected consonant changes (CVC vs. CVCC). The results indicate that native phonotactic constraints have a large effect on adult perception but a small effect on infant perception.