Implosive Consonants: Their representation and sound change effects

Abstract. Oromo, a Cushitic language spoken in Ethiopia and Kenya, shows certain phonologically irregular phenomena with respect to the coronal implosive consonant that have never been explained satisfactorily. First, in some dialects, roots ending in a short /d/ behave like final-/?/ roots while in some others they behave like fmal-/t/ roots. Secondly, unlike the geminates of all other consonants, which behave like heterogeneous abutting consonants, the long implosive behaves, in some cases, like a single segment. Finally, it is sometimes assumed that in Proto-East-Cushitic, there is evidence for reconstructing two different implosive phonemes in the denti-alveolar region, i.e. *d and *d1, although no one has yet established the relevant difference between them. The aim of this paper is to provide a unitary account of all these facts by proposing an adequate underlying representation of single and long implosives within the model of Feature Geometry as well as suggesting a different diachronic origin for both types of reconstructed implosives.