The acoustic vowel space of Anyi in light of the cardinal vowel system and the Dispersion Focalization Theory

The Cardinal Vowel System (CVS) and the Dispersion Focalization Theory (DFT) make an
important assumption about the inventory of vowels in world languages. The claim is that
languages organize their vowels in a certain way in the auditory-perceptual space so as
to maximize intelligibility. The vowel diagrams of African languages in influential publica-
tions such as Welmers (1973: 20–45) explicitly or implicitly reflect this assumption. However,
persistent confusions between [ɪ] and [e] among Anyi Morofu speakers have aroused my
curiosity and led me to investigate the matter acoustically. The findings reported here show
that the vowel space of Anyi Morofu is in a between and betwixt state. The data indicates
that this dialect is moving from a nine-vowel system to an eight-vowel system through the
merger of [ɪ] and [e]. There are also signs of the impending merger of [ʊ] and [o].