Interspeaker variation on VOT merger and shortening in Seoul Korean

Recent studies show that, besides their effect on the f0 contour of the following vowel, Korean stops are undergoing a sound change in which a partial or complete VOT merger is taking place between aspirated and lax stops. Previous studies on sound change have mainly focused on group-normative effects, that is, effects that are representative of the population as a whole. The present study investigated interspeaker variation on sound change and focused on the role of the individual in the actuation of sound change. To see interspeaker variation, factors such as age, gender, dialect, and L2 proficiency were controlled. The results showed that the pooled data showed the VOT merger. However, individual speakers showed remarkable variations as follows: First, VOTs for both stops are getting shorter (VOT shortening). Second, there was an aspirated-shortening process. Third, there was a lax-lengthening process. Fourth, there is a merger variation. Remarkable interspeaker variations with controlled factors suggest: first, some speakers can be early adopters of sound change and more active propagators than others. Second, Korean is still undergoing a sound change. Further study is necessary to see whether there is a relationship between the merger and the shortening process.