A Minor Historical Rule of GRAVE Concern in the Volta-Comoe Languages.

The Volta-Comoe languages¹ belonging to Greenberg's (1963) Niger-Congo undergo a historical change in which underlying labial /b/ is reflexed as velar [g] and labio-palatal [...] in their Central members and as [b] in their Eastern and Western subgroups. We maintain that this process can be accounted for naturally by positing the feature Grave proposed by Jakobson, Fant and Halle (1956) in their early work on distinctive-feature phonology. This permits one to say that a non-back grave segment changed to a back one in specified linguistic contexts. Other processes which help explain the change are palatalisation, vowel-labialisation, consonant-labialisation and velar fronting. [ABSTRACT FROM AUTHOR]