Neutral vowels in sound-symbolic vowel harmony in Korean

The set of neutral vowels in the vowel-harmony pattern found in Modern Korean sound-symbolic words is traditionally considered to consist of two members: [i] and [É̈]. Some authors have tentatively put forward the hypothesis that [u] and [y] are also neutral. A corpus study on the phonotactics of Korean sound-symbolic vowel harmony provides quantitative support both for the traditional understanding of [i] and [É̈] as neutral vowels and for the tentative hypothesis that [u] and [y] are also neutral. Additionally, the corpus study reveals that vowels are neutral to different degrees. The vowel [a] is shown to be partially neutral, but unlike the other neutral vowels which are transparent, [a] is partially opaque. The distribution of diphthongs is also studied.