Development of perception of second language Japanese geminates: Role of duration, sonority, and segmentation strategy

This study explored the second language perceptual accuracy of Japanese geminates (moraic units) by English-speaking learners at three proficiency levels: beginner (28), low–intermediate (42), and advanced (15). Stimuli included singleton and geminate /t/, /k/, /s/ followed by /a/ or /u/ produced by a native speaker in isolated words and carrier sentences. Results of a forced-choice identification task revealed a significant complex interaction involving all factors. Simple effects tests indicated scores for geminate /s/ followed by /u/ in carrier sentences were significantly lower across proficiency levels. The singleton-geminate contrast for /t, k/ was significant for beginning learners, marginal for low– intermediate, and nonsignificant for advanced. Duration differences did not account for all findings. Greater consonant–vowel sonority difference facilitated perception, enhancing mora boundaries for speech segmentation.