Neutralization of Vowels /ɨ/ and /u/ after a Labial Consonant in Korean: A Cross-generational Study

Abstract

This study investigated whether Korean vowels, /ɨ/ and /u/, are distinctively perceived after a labial consonant given thefact that native and Sino-Korean nouns showed only vowel /u/ after a labial consonant while this pattern was massivelybroken by the recent introduction of loanwords. For this purpose, a perception experiment was conducted with V1C1V2 sequences in which different vowels /a, i, u/ andconsonants /p, t, k/ occurred in V1 and C1 before the target V2, /ɨ/ and /u/. The data was produced by six speakers each fromtwo different age groups, Age20 and Age40/50 in the read speech style. The results showed that consonant /p/ attractedsignificantly more responses of /u/ from /VCɨ/ sequences and significantly less responses of /u/ from /VCu/ sequence than theother consonants did in both age groups. Furthermore, Age20 group showed significantly less percentage of /u/ responses thanAge40 group when the preceding consonant was /p/ regardless of the target vowel. We suggest therefore that unlike the traditional belief of labial assimilation, there is neutralization after a labial consonantin which vowels /ɨ/ and /u/ are often realized as any sound between two vowels, /ɨ/ and /u/. That is, this vowel change isnot categorial but it rather produces an ambiguous stimulus which attracts different responses from different listeners. Ambiguous stimulus was produced due to coarticulatory efforts in speech production and perceptual compensation. We alsoargue that there is generational difference such that Age40/50 group speakers showed stronger tendency to produce /u/ after alabial consonant regardless of whether the target vowel was /ɨ/ or /u/.