In this ultrasound study, we compared the gestures and their relative timings for Japanese geminate obstruents produced by a native Chinese speaker and a native Japanese speaker, with special focus on the tongue tip (TT) rising gesture. The duration of TT gesture was shorter in the learner’s speech compared to the native speaker. However, for both speakers, the onset of TT rising gesture overlapped with the production of the preceding vowel. We also observed that while TT gesture of the native speaker is accompanied with simultaneous tongue blade (TB) rising gesture, the two gestures occur in sequence for the learner. Taken together, the results suggest the need for further acoustic analyses as well as articulatory analyses beyond TT gesture, including other relevant articulatory gestures.

Recently the number of ultrasound studies regarding learning challenging sounds in foreign languages, as well as in one's L1, has been increasing. Ultrasound can be employed in language classrooms as well as for fieldwork, based on its non-invasiveness, portability and safety. Visualization of normally hidden tongue shapes allows learners to get instant visual feedback, and teachers to get a bridge between theory and practice. Case studies will show how it is used in EFL-related flexible learning contexts and articulatory phonetics research. Midsagittal and coronal, individual and group, qualitative and quantitative methods will be discussed.

This presentation introuces the Corpus of Everyday Japanese Conversation (CEJC), which was released in March 2022. The main features of the CEJC are i) that we target conversations embedded in naturally occurring activities in daily life; ii) that we collect various kinds of everyday conversations in a balanced manner; and iii) that we collect and publish not only audio but also video data. The CEJC contains 200 hours of speech, 577 conversations, about 2.4 million words, and a total of 1675 conversants. In this talk, we present the design, the construction, and the availability of the CEJC.