当社の Vowel space varia… regional : English in 語学・辞書・学習参考書
Vowel space in English : regional varia…,vowels_lex_sets_061115.jpg,POIB: RGB color space → IPA vowels,Colour online) The representation of the FOOT-STRUT vowels,Robustness and Complexity in Italian Mid Vowel Contrasts