Sonority and central vowels: A cross-linguistic phonetic study

This paper reports results of a cross-linguistic study of four potential acoustic correlates of vowel sonority. Duration, maximum intensity, acoustic energy, and perceptual energy are measured in five languages (Hindi, Besemah, Armenian, Javanese, and K(w)ak'(w)ala) in order to determine whether there is an acoustic basis for the position of schwa at the bottom of vocalic sonority scales. The five targeted languages belong to two groups. In three languages (Armenian, Javanese, and K(w)ak'(w)ala), the reduced phonological sonority of schwa relative to peripheral vowels is manifested in the rejection of stress by schwa. In two languages (Hindi and Besemah), on the other hand, schwa is treated parallel to the peripheral vowels by the stress system. Results indicate that schwa is differentiated from most vowels along one or more of the examined phonetic dimensions in all of the languages surveyed regardless of the phonological patterning of schwa. Languages vary, however, in which parameter(s) is most effective in predicting the low sonority status of schwa. Furthermore, the emergence of isolated contradictions of the sonority scale whereby schwa is acoustically more intense than one or more high vowels suggests that phonological sonority in vowels may not be quantifiable along any single acoustic dimension.