ATR vowel harmony in Akposso

This paper presents a description of the vowel harmony system of Akposso (Uwi), a Kwa language of Ghana and Togo, one of only a handful of Kwa languages with a complete ten vowel system with ATR harmony. However, the tenth vowel, hi, does not function as the harmonic counterpart of the low [-ATR] central vowel lal in affixes as it does in other ten vowel languages with crossheight vowel harmony systems. Rather, in some instances Ia! alternates with lei in [+ATR] contexts, while in other instances it surfaces invariably as lal in both [-ATR] and l +ATR] contexts. Formant measurements show the [+ATR] central vowel occupying the mid area of acoustic space, thus adding some support to the view that [+ATR] central vowels in ATR harmony systems are phonetically nonlow rather than low, the more widely-assumed position. Although vowel harmony applies to a significant number of affixes, especially in the verb morphology, there are interesting limitations on how far harmony extends.