著者
大野 眞男 久野 眞 杉村 孝夫 久野 マリ子
出版者
日本音声学会
雑誌
音声研究 (ISSN:13428675)
巻号頁・発行日
vol.4, no.1, pp.28-35, 2000-04-28 (Released:2017-08-31)

The South Ryukyu dialects are divided into two categories: one of which basically has three vowels /i ・ a ・ u/, and the other, four /i ・ ï ・ a ・ u/. The former is assumed to be derived from the latter by the decline of the neutral vowel /ï/. This neutral vowel has been interpreted and transcribed differently in phonetic notation by many researchers, e.g., [ï, ɨ, 〓]. The purpose of this article is to analyse the acoustic substance of these neutral vowels, using the digitized phonetic sources of the Aragusuku dialect as reported in Kuno et al. (1993), and the Karimata dialect and Oogami dialect as reported in Oono et al. (1998). According to Imaishi (1997), the characteristics of the neutral vowel can be seen from examination of F2. Although the distribution of F2 of the neutral vowels in all of these dialects locates between [i] and [u], the values of F2/F1 differ significantly among these dialects. This is supposed to be affected by the difference of articulatory position of the vowels in question. The value of F2/F1 of Oogami dialect is especially low, and in part overlaps with that of [u]. This means that the tongue position of the neutral vowel in Oogami is very close to that of [u]. Presumably, the distinction between the two vowels depends on the configuration of the lips, spread vs. round.