Journal of Phonetics (1996) 24, 295-312

Acoustic and perceptual evidence for complete neutralization of manner of articulation in Korean

Hyunsoon Kim and Allard Jongman

While most studies of neutralization have focused on word-final devoicing, the present study investigated a different kind of neutralization, namely that of manner of articulation. Korean has a rule of Coda Neutralization, whereby word-final coronal obstruents (e.g., /t, th, s/) are all phonetically realized as [t]. Experiment l shows that Korean vowels preceding non-final heterosyllabic fricatives are longer than when preceding non-final heterosyllabic oral stops. Making use of this fact, vowel and closure durations of word-final VC sequences were measured in Experiment 2 to determine whether the speech signal contained any acoustic cues to the underlying manner distinction. Data from four speakers suggest that neutralization of manner as reflected in vowel and closure duration is phonetically complete. Moreover, complete neutralization is observed despite the fact that Korean orthography distinguishes between the different underlying consonants. An additional finding is that 83% of all word-final stops in this study were followed by a brief burst. This is of particular interest given the long tradition in Korean phonology of considering coda neutralization to yield unreleased stops. Finally, perceptual results from Experiment 3 show that listeners were unable to reliably determine from which underlying form a given surface form had been derived, thus indicating that other potential cues besides duration had been neutralized. Taken together, the present results suggest that Korean manner neutralization offers a perhaps rare instance of the standard view of neutralization, producing outputs which are not distinguished in either production or perception.