Articulatory and acoustic variability of glottalized sonorant codas in Hakha Lai

Non-modal sonorants cross-linguistically exhibit gestural asynchrony, resulting in modal and non-modal portions. This asynchrony can exhibit substantial variation; for example, Maddieson (2002) and Bird et al. (2008) find variability in glottalized sonorants, observing glottalization (i.e., creak) pre-, post-, and mid-segment (i.e., [n n∼ n∼ n n n∼ n]). Hakha Lai, a South-Central Tibeto-Burman language, has both onset voiceless sonorants [m̥ n̥ ŋ̊ l̥ r̥] and coda glottalized sonorants [mˀ nˀ ŋˀ lˀ rˀ]. Previous work (Ziegler etal., 2023; Ziegler, 2024) found that HL voiceless sonorants exhibit strong articulatory variability in the coordination of voicelessness and oral constriction despite persistent and strong acoustic cues. The articulatory and acoustic characteristics of the glottalized sonorant codas remain unexplored. Using data from 5 HL speakers (4F, 1M), this work provides an acoustic analysis of Hakha Lai glottalized sonorants to determine (a) the temporal coordination (and variability) of glottalization, (b) the acoustic cues used to contrast coda modal and glottalized sonorants (including F0, spectral tilt, harmonics-to-noise ratio, strength of glottal excitation, and vowel duration/quality), and (c) whether variability across manner of articulation (nasal versus liquid) is observed in parallel to onset voiceless sonorants.