Coarticulation effects of Korean sibilant /s/ before a high front segment

Abstract

This paper investigates acoustic characteristics of Korean /s/ before a high front segment and argues that Korean /s/ shows acoustic characteristics of a palatalized segment due to the coarticulation with the following high front segments. In Experiment, it is shown that the first 30 msec of /s/ before /i, ye, ya/ shows spectral peaks around 4 kHz whereas /s/ before open vowels like /e, a/ shows peaks around 6 kHz. We suggest that this is due to the tongue body position at the palatal area placed at the beginning of /s/ when it is followed by /i/ or /y/. Center of gravity frequency, and band energy difference also show differences of Korean /s/ in different contexts. Based on the results of this experiment, we argue that Korean /s/ is modified from its beginning due to the coarticulation with the following segments if articulators of /s/ are compatible with those of the following segments. Interestingly, this paper also shows that in case /s/ is followed by /yu/ or /yo/, its spectral shape shows significant differences from /s/ followed by /ya/ or /ye/. It raises the question that in Korean the domain of coarituclation may be larger than the target and its immediately surrounding segment.