Schwas with and without active gestural control.

摘要

This study investigated whether some epenthetic vowels are targetless, that is, whether they can arise from the timing of two consonants. Specifically, past tense ("epenthetic") schwas were compared to lexical schwas in American English. Assuming that there is a continuous vowel production on which consonants are superimposed (see e.g., Ohman, 1966), a targetless vowel would have the tongue position of either the preceding vowel or the following one or a mix of both.;Articulatory data were collected from three speakers of American English using an electromagnetic midsagittal articulometer. The stimuli included phrases with past tense and lexical schwas embedded in a common environment V1C1eC2 V2 where V1 and V2 were identical (eight different vowels were used, five front and three back) and where C1 and C2 were tongue tip gestures. For example, "if needed even once" (past tense schwa) versus "if Needa'd even known" (lexical schwa).;Even though no systematic qualitative difference was found between the two types of schwas and both schwas were heavily context-dependent, the tongue position during the past tense schwa was still found to be more context-dependent than the tongue position during the lexical schwa.;This study thus demonstrated the possibility of targetlessness, which can readily be expressed in Articulatory Phonology (e.g., Browman and Goldstein, 1986, 1990a, 1992a). In this theory and model, the basic units are articulatory gestures, and timing of gestures can be specified in a direct manner so that a vowel can arise from the timing of two consonantal gestures and, articulatorily, take on the characteristics of the surrounding vowels.;The possibility of targetlessness also provides support for a gestural account of the past tense allomorphy: An Obligatory Contour Principle violation is temporal in nature (two identical consonants cannot overlap), and a temporal solution (separating the two overlapping tongue tip gestures) is preferred over vowel epenthesis. The possibility of targetlessness thus also illustrates further the vital role that temporal relations play in phonology and morphology.