/W/-Variants in Korean

No systematic study has examined the relationship between acoustic variability and /w/-deletion in Korean. Most previous studies on /w/-deletion have described /w/-variants in categorical terms, i.e., /w/-deletion or a full glide (Silva 1991; Kang 1997; Yun 2005). These studies are based either on impressionistic judgements without a systematic acoustic analysis or on an exclusive examination of internal acoustic variability of /w/ such as F2, without examining the availability of external acoustic cues such as voice onset time (VOT) of a consonant. However, given the important influence of the adjacent sounds for segmental realizations, it is necessary to examine possible acoustic variability in the differentiation of /w/-variants. The present study aims to address this issue by evaluating the acoustic properties of /CwV/, including VOT and formant transitions. In the analysis, 432 tokens in word-initial position (216 /CwV/ words and 216 /CV/ words) were examined. The results indicated that /w/ exhibits four different variants. Firstly, /w/ is realized as a full glide. Such a variant is characterized by a VOT difference and significant differences in F1 and F2 at voicing onset compared with /CwV/ and /CV/. Secondly, /w/ can be maintained but coarticulated with the following vowel. Such a variant is demonstrated by differences in VOT and F2. Thirdly, /w/ is categorically deleted, which is indicated by the absence of any differences in VOT, F1, and F2. Fourthly, /w/ overlaps a consonant. The F2 difference without VOT difference is manifested in the variant. In contrast to VOT, F1, and F2 differences, pitch plays little role in determining /w/-variants in Korean. These findings suggest that allophones can be produced along a gradient continuum of acoustic cues, exhibiting sounds intermediate between the full realization of a given category and its deletion. Furthermore, each variant can be cued by a set of internal and external acoustic cues.