Articulatory modification of /m/ in the coda and the onset as a function of prosodic boundary strength and focus in Korean

An articulatory study (using an Electromagnetic Articulography, EMA) was conducted to explore effects of prosodic boundary strength (Intonational Phrase/IP versus Word/Wd), and focus (Focused/accented, Neutral, Unfocused/unaccented) on the kinematic realization of /m/ in the coda (<TEX>${\ldots}$</TEX>am#i<TEX>${\ldots}$</TEX>) and the onset (<TEX>${\ldots}$</TEX>a#mi<TEX>${\ldots}$</TEX>) conditions in Korean. (Here # refers to a prosodic boundary such as an IP or a Wd boundary). Several important points have emerged. First, the boundary effect on /m/s was most robustly observed in the temporal dimension in both the coda (IP-final) and the onset (IP-initial) conditions, generally in line with cross-linguistically observable boundary-related lengthening patterns. Crucially, however, in contrast with boundary-related slowing-down effects that have been observed in English, both the IP-final and IP-initial temporal expansions of Korean /m/s were not accompanied by an articulatory slowing down. They were, if anything, associated with a faster movement in the lip opening (release) phase (into the vowel). This suggests that the mechanisms underlying boundary-related temporal expansions may differ between languages. Second, observed boundary-induced strengthening effects (both spatial and temporal expansions, especially on the IP-initial /m/s) were remarkably similar to prominence (focus)-induced strengthening effects, which is again counter to phrase-initial strengthening patterns observed in English in which boundary effects are dissociated from prominent effects. This suggests that initial syllables in Korean may be a common focus for both boundary and prominence marking. These results, taken together, imply that the boundary-induced strengthening in Korean is different in nature from that in English, each being modulated by the individual language's prosodic system. Third, the coda and the onset /m/s were found to be produced in a subtly but significantly different way even in a Wd boundary condition, a potentially neutralizing (resyllabification) context. This suggests that although the coda may be phonologically 'resyllabified' into the following syllable in a phrase-medial position, its underlying syllable affiliation is kinematically distinguished from the onset.