Vowel length effects on the perception of geminate and singleton stop boundaries by Korean learners of Japanese

Generally, closure duration is a primary cue used to distinguish plosive geminate and singleton stops (Fukui, 1978). However, closure duration is not an absolute value. It is relative. That is, closure duration is controlled by the neighboring phonemes. However, it is not yet clear what factors affect the closure duration at the perceptual boundary between geminate and singleton stops by either Japanese native speakers or by Korean learner of Japanese. Accordingly, this paper investigates the relationship between the preceding vowel and the closure duration at the perceptual boundary by Japanese native speakers and Korean learners of Japanese. Concretely, this paper’s research questions are as follows. First, what is the relationship between the preceding vowel length and the perceptual boundary of the geminate and singleton stops? Second, what are the differences, if any, between the perceptual boundary of Korean learners of Japanese and that of Japanese native speakers?