Evidence of diachronic sound change: A comparative acoustic study of Seoul and Kyungsang Korean

The phonetics and phonology of the Kyungsang dialect of Korean is distinct from those of the standard Seoul dialect with regard to segments and lexical pitch. However, whether the distinctive phonetics and phonology of Kyungsang Korean are maintained by younger speakers is questionable due to the increased exposure to Seoul Korean and the prevailing linguistic ideology that has lent Seoul Korean a strong normative bias. The current dissertation investigated diachronic sound change in Kyungsang Korean based on the acoustic data collected from forty female Korean speakers (10 younger and 10 older speakers each for Kyungsang and Seoul). Acoustic evidence for sound change is provided by showing generational differences in the phonetics of Kyungsang Korean, and comparison of the phonetics between Kyungsang and Seoul Korean addressed how a prestigious national standard language affects dialect re–formation. In the acoustic study of vowels (Chapter 2), measures of formant frequencies showed that the merged /ʌ/ and /ɨ/ vowels for older Kyungsang speakers are split among younger speakers, resulting in the same vowel system between younger Kyungsang and Seoul speakers both of which have seven vowels. The study of stop consonants (Chapter 3) showed generational differences for the measures of VOT and F0 in distinguishing the three–way laryngeal contrast among voiceless stops for Kyungsang speakers. Younger Kyungsang speakers rely more on F0, but less on VOT to distinguish the stops than older speakers do. The increased role of F0 to the laryngeal contrast for the younger Kyungsang speakers corresponds with the diachronic change in Seoul Korean where the role of VOT is reduced, but that of F0 is increased for younger Seoul speakers. In the acoustic study of fricative (Chapter 4), measures of fricative duration and center of gravity showed that while the two–way fricative contrast is less distinct for older Kyungsang speakers, younger Kyungsang speakers well distinguish the two fricatives similar to Seoul speakers. As a consequence of the generational change in the segments of Kyungsang Korean, younger Kyungsang speakers do not maintain the vowel and consonant features unique to Kyungsang Korean, but rather approximate to those of Seoul Korean. The current dissertation showed evidence for the diachronic sound change in the lexical pitch accent of Kyungsang Korean for both surface and underlying forms (Chapters 5 and 6). F0 spectral and temporal properties characterizing contrastive lexical accents are less distinct for younger Kyungsang speakers than for older speakers. Notably, F0 peak shifted rightwards for younger Kyungsang speakers across all accent classes, resulting in the final rising accent pattern similar to Seoul Korean. The generational difference in the lexical accents of Kyungsang Korean was also observed for underlying forms (Chapter 6). Elicited accent patterns for monosyllabic and disyllabic nouns under suffixation showed that the accent system of younger Kyungsang speakers is simpler than that of older speakers and similar to that of Seoul speakers, which results from accent merger, loss of suffix tone, and weakened accent contrasts. The direction of the sound change observed in the current dissertation suggested that the phonetics and phonology of Kyungsang Korean is re–formed to approximate Seoul Korean