Gradual tongue movements in Korean Palatalization as coarticulation: New evidence from stroboscopic cine-MRI and acoustic data

The present study addresses whether Korean Palatalization is phonological or phonetic with tongue movements being the same as in the vowel /i/ or gradual during a target consonant. For this purpose, we conducted stroboscopic cine-magnetic resonance imaging (MRI) experiments from two native speakers of Seoul Korean and examined whether tongue raising and fronting are the same as in the vowel /i/ in two types of Korean Palatalization: (a) when the consonants /t, th, tˈ, ts, tsh, tsˈ/ occur before /i/ within a morpheme and (b) when the consonant /t/ occurs before /i/ across a morpheme boundary. The MRI finding that the tongue gradually rises and advances before and during the target consonants is further confirmed by our acoustic data on F1 and F2 values of vowels surrounding the target consonants /t, ts/ taken from ten speakers of Seoul Korean including one subject in the articulatory experiment. The acoustic data also show that the intervening consonants in V1CV2 sequences are transparent in V-to-V transitions, giving rise to not only anticipatory coarticulation but also carryover coarticulation. It is concluded that there is a V-to-V coarticulation, not a phonological process of palatalization both within a morpheme and across a morpheme boundary, and that gradual tongue movements in the coarticulation with a following vowel /i/ reinforce the phonetic implementation of stridency ([+strident]) in the phonological process of Korean Affrication.

► We examined whether Korean Palatalization is phonological or phonetic.
► Stroboscopic cine-MRI data showed gradual tongue fronting and raising.
► Gradient F1 and F2 values of vowels were found before and during target consonants.
► Transconsonantal V-to-V transition and longer frication before /i/ were also observed.
► We suggest that Korean Palatalization is a V-to-V coarticulation, not phonological.