Targetless schwa revisited

It has been suggested that schwa vowels in English lack vowel quality targets, that is, they are realized as interpolations between the preceding and following segmental contexts or are the result of separating two consonantal constriction gestures, without an inherent vocalic gesture. Tests of this hypothesis have produced mixed results. The present study revisits the question of schwa targets based on acoustic analysis of schwa vowels in a wider range of segmental and morphological contexts. The main conclusions are: (i) It is important to distinguish stem-final reduced vowels (as in ‘‘pandA’’) from other schwa vowels (e.g., ‘‘About,’’ ‘‘bEgin’’). The former clearly have vowel quality targets they are generally mid central vowels whereas the latter are much more contextually variable. (ii) The variable schwa vowels have a target, but this target is not a particular vowel quality, it is to indicate the presence of a vowel. This is achieved through a variety of means, including duration and realization of a local amplitude peak, but is consistent with substantial variation in vowel quality, particularly F2.