Anticipatory and Carry-Over Nasal Coarticulation in the Speech of Children and Adults

Producing /n/ requires a lingual constriction to be formed and the velopharyngeal port (VPP) to be opened. This study examined interarticulator timing in the speech of adults and children aged 5 and 10 years. A new acoustic method was developed to determine the time at which VPP opening began during vowels spoken in the context of /d_n/, and VPP closing reached completion in vowels spoken in the context of /n_d/. Adults and children alike nasalized most of the vowels in the /d_n/context. This suggested that the children's speech was not more "segmental" than adults'. It suggested, further, that nasalizing vowels in a /d_n/ context is a natural speech process that need not be learned by young children. The children, like the adults, nasalized most of the vowels spoken in the context of /n_d/. The lack of significant between-group differences, taken together with several other findings of the study, is consistent with the view that the temporal domain of carry-over nasal coarticulation is determined largely by the time needed to close the VPP (i.e, by inertial properties of the speech production mechanism).