Are opaque patterns what we think they are? The acoustics of the Bengali vowel chain shift

Abstract

The chain-shift pattern of vowel height harmony in Bengali, in which low and mid vowels in monosyllabic verb stems alternate with mid and high vowels, respectively (ae~e, e~i, ɔ~o, o~u), is reported in the phonological literature and by Bengali linguists to be exceptionless. Experimental evidence, however, indicates that Bengali speakers extend this pattern to nonce verbs only about half the time when low vowels are involved. This raises questions about the productivity of the attested pattern, echoing the results of experimental tests of chain shifts in other languages (e.g., Polish, Taiwanese) in which speakers fail to extend opaque phonological patterns to nonce words. One question we may ask is whether the phenomenon described in the literature as an alternation truly neutralizes the vowel height contrasts in the Bengali language. This research presents instrumental acoustic analysis of Bengali vowels produced by native speakers in real and nonce verbs in order to address this question and gain new insight into both the quality of the vowels produced as a result of harmony in real words and how speakers apply the pattern with nonce verbs.