Ikwere Nasal Harmony in Typological Perspective

This paper addresses the question: why are some consonants more resistant to nasalization than others? It presents data from Ikwere, an Igboid language spoken in Nigeria, which sheds new light on this question. Ikwere has a pattern of nasal harmony which spreads nasality across certain domains within the word. Certain consonants undergo nasalization while others block its spread. The class of blocking segments comprises all obstruent stops and fricatives. However, the two nonexplosive labial stops represent an apparent exception in that they fail to block nasalization. A phonetic study of these sounds, reported below, shows that they are not in fact obstruents as they produced with no buildup of air pressure behind the labial closure. The full generalization is thus that all and only obstruents block nasalization. On the basis of this result, it is proposed that the basic property underlying the scale of resistance to nasal spreading is obstruence, that is, degree of intraoral air pressure during the constriction. Consequences for the typology of nasalization and for feature theory are considered