2014/10/09

Kang, Y. (2014) Voice onset time merger and development of tonal contrast in Seoul Korean stops: A corpus study. Journal of Phonetics, 45, 76–90

Presentation: Hsiang-Yu

Summary: Sarah

This study explores the relationship between the merging of voice onset timing (VOT) in stops and tonal contrasts in Korean. Although it has been shown in previous research that the three-way contrasted stops (aspirated, lenis, fortis) in Korean are distinguished by both VOT and F₀, a number of studies indicated that the VOT distinction between aspirated and lenis stops is disappearing. From the perspective of tonogenesis, this merging is suggested to result from the tonal contrast between the accentual phrase-initial boundary tones HH and LH, whose occurrences nicely correspond with phrase-initial segment types: HH is associated with [-stiff vocal folds] segments such as lenis stops or sonorants, while LH co-occurs with [+stiff vocal folds] ones like aspirated stops or /h/. It is reasoned that since F₀ is already a sufficient cue for contrasting the two stops, the difference in VOT gradually dies out. To verify this account, a corpus-based analysis was conducted, which included in total over one hundred speakers across different gender and age groups. VOTs of stop productions and F₀ of the following two vowels were measured. Results showed that the VOT difference between aspirated and lenis stops indeed exhibited a decreasing trend, and this change was primarily led by females. For F₀, aspirated and lenis stops, along with the non-stop segments in the [+stiff vocal folds] and [–stiff vocal folds] categories, were accompanied by high and low F₀, respectively. In further analyses, it was demonstrated that the distinction between aspirated and lenis stops in the F₀ domain was gradually more and more emphasized across time for both males and females, but the reliance on VOT was nonetheless only found for males. It was thus concluded that the merging of VOT in Korean stops has a tonogenesis motivation, and such a tonal effect applies not only to stops but also to more abstract categories that are characterized by phonological features .