The Mbam languages of Cameroon have a unique position in Bantu linguistics. Being in between “narrow” Bantu and “wide” Bantu, they sometimes pattern with the one and sometimes with the other, and as such are a rich motherlode for comparative and historical research. The Mbam languages have another point of interest as well. They have been previously analysed as standard 7 vowel languages (/i,e,ɛ,a,ɔ,o,u/) with Advanced Tongue Root (ATR) harmony. While vowel harmony in African languages has received a lot of attention and study, and the vowel-harmony systems of not a few of the Mbam languages have been studied, most of the previous studies have been on individual languages. This study seeks to analyse and compare the vowel systems of ten Mbam languages as a group: both their vowel inventories and their vowel-harmony systems. Various issues in vowel harmony, such as neutral vowels, directionality in and domains of vowel harmony are discussed. This study also proposes a phonological explanation for the functioning of the complex vowel-harmony systems found in the Mbam languages. Finally this study considers the internal classification of the Mbam languages and their position in the wider linguistic context of the Bantu and Bantoid languages.
Boyd, Virginia, Phd. The phonological systems of the Mbam languages of Cameroon with a focus on vowels and vowel harmony. LOT, Utrecht: 2015.