Acoustic-perceptual factors in nasal place assimilation.

Abstract

Phonologically, nasal consonants often assimilate to the place of a following oral stop. While the source of this assimilation is generally taken to be anticipatory coarticulation, this study examines the possibility that acoustic-perceptual factors are partially or even primarily responsible. Two American English speakers produced /zV́NCschwa/ tokens (V=/i/, /æ/, /schwa /;NC=/mb/, /nd/, /hooked en g/). Stimuli were split into /zVN/ and /Cschwa/ portions. /zVN/ portions whose final N was identified with at least 97% accuracy (four judges) were cross-spliced with /Cschwa/ portions to yield all possible N–C pairings. Listeners identified N and C of the cross-spliced /zV́NCschwa/ stimuli. Homorganic clusters were correctly identified 95% of the time (preliminary results with eight listeners). Listeners varied in accuracy of N identification in nonhomorganic clusters, but across subjects one-third of nonhomorganic nasals were misidentified, with homorganic responses comprising 80% of these errors. Although different places of articulation showed different response patterns, overall results indicate that place cues for nasals may be overridden by those of a following oral stop. Even nasals whose place is unambiguous in final position may shift perceptually before heterosyllabic oral stops.