The acoustics of word-initial and word-internal voiced stops in Somali

Abstract

This article seeks to determine the acoustic correlates of gemination in Standard Somali (Afroasiatic, Cushitic), in particular whether closure duration is the primary acoustic correlate distinguishing singleton and geminate stops, with immediate consequences for the analysis of word-initial strengthening. We provide an acoustic analysis of word-initial and word-internal voiced singletons as well as of their geminate counterparts on the basis of a production experiment conducted with four native speakers. Three temporal and four non-temporal acoustic properties of /b d ɡ/ and /bb dd ɡɡ/ are examined and systematically compared (closure duration, release burst duration, vowel duration; and closure amplitude, release amplitude, presence of a release burst, (de)voicing). We argue that the opposition between singleton and geminate voiced stops is primarily realized as the manner contrast approximant [β̞ ð̞ ɣ̞] vs. stop [b d ɡ]. Word-initially, Somali exhibits various peculiarities that are reminiscent of the cross-linguistically attested phenomenon of domain-initial strengthening. This article provides the first study of this phenomenon in Somali. We establish that word-initial /b d ɡ/ and word-medial /bb dd ɡɡ/ share the same closure duration, release burst duration, and vowel duration within the Prosodic Word. They also have a similar closure amplitude, and voicing properties. Moreover, the acoustic properties of word-initial /b d ɡ/ remain constant, and do not depend on their position in the prosodic hierarchy. On the basis of these results, the article also aims at providing new insights in the phonological representation of Somali geminates and word boundaries, and thus contributes to the understanding of word-initial strengthening in Somali.