What’s in a Schwa?

Abstract

Abstract Although the schwa sound is by far the most frequent vowel in Dutch, it has up to now been phonetically the most neglected. We used an existing database of vowel sounds from focus words in spontaneous speech and in lexically the same text, read aloud by one male speaker, to analyse durational and spectral characteristics of schwas, and we compared the results with data on schwa diphones used in Dutch text-to-speech synthesis. It turned out that, contrary to what is usually thought, lexical schwa sounds in natural continuous speech are considerably shorter than other short vowels, that there is no strong consonantal influence on schwa duration, that schwa sounds display a spectral spread larger than any other vowel, and that surrounding consonants seem to play a role with respect to the midpoint formant distribution of the schwa within the whole vowel system. In no way can the schwa be considered as the ‘bench-mark’ of a speaker’s vowel system.