Lisboa, Lisbon, and the exception

Abstract

The graphemic form <Lisbon> in the title refers to an underlying [ˈlɪzbən] with a voiced heterosyllabic /zb/ cluster. Chomsky and Halle (1968, p. 150, n. 105) indicate the example Lisbon as one of the exceptions to the devoicing of obstruent clusters in English. Corresponding orthographic <sb> clusters in Portuguese obey a rule according to which a [ʒ] occurs as the phonetic realization of an underlying and unspecified for voice and place of articulation /S/ that assimilates the voicing of the following consonant [b], as in Lisboa [liʒˈboɐ]. It should be borne in mind that not only are /zb/ clusters exceptional in English but that /zb/ and /sb/ may be equally licensed (as in asbestos), while the cooccurrence of voiced and voiceless segments within a cluster is not possible in Portuguese. This paper aims at obtaining answers to the following research question: do native speakers of English experience difficulties when producing Portuguese voiced sC heterosyllabic clusters, taking into account (a) the different syllable structures of these clusters in the L1 (English) and the L2 (Portuguese), and (b) the assimilation process in Portuguese, whereby if C is voiced in sC, then /S/ = [ʒ]? The main conclusions are that assimilation seems less problematic than palatalization for native speakers of English when producing heterosyllabic word-medial Portuguese sC clusters and that individual differences may play an important role. More research is needed, with a focus on instruction and with more informants, to confirm or dismiss these conclusions.