The tongue position and gestural timing of palatalized /p/ in Japanese

Palatalization has been broadly characterized as involving tongue fronting, tongue raising, and spirantization [Bateman, 2011]. While its acoustic and phonological effects are well documented, the articulatory realization, particularly the tongue target of palatalized /p/ in Japanese, remains underexplored. This study investigates the articulation of palatalized /p, t, s, k/ in /paCja/ sequences by native speakers of Japanese using ultrasound tongue imaging. Preliminary results show that the tongue gesture during palatalized /p/ approximates the hard palate as expected. Palatalized /p/ is sometimes described as a consonant cluster /pj/ in Japanese; however, gestural timing analysis revealed that the C-center effect, commonly associated with consonant clusters, was not consistently observed across speakers. Furthermore, the tongue body gesture for /j/ seemed to have substantial temporal overlap with the lip gesture, as the /j/ gesture often began before the /p/ closure. This high degree of overlap suggests an in-phase coordination between /p/ and /j/, rather than an anti-phase pattern typical of clusters. These findings support the view that Japanese may employ a specific gestural timing system to maintain moraic structure and that some speakers may treat palatalized /p/ as a single coordinated unit rather than a true consonant cluster.