On pitch lowering not linked to voicing: Nguni and Shona group depressors q Laura J. Downing Zentrum fu ¨ r Allgemeine Sprachwissenschaft, Schu ¨ tzenstraße 18, 10117 Berlin, Germany With an Appendix by Thilo C. Schadeberg Abstract This paper tests how well two theories of tone–segment interactions account for the lowering effect of so-called depres- sor consonants on tone in languages of the Shona and Nguni groups of Southern Bantu. I show that single source theories, which propose that pitch lowering is inextricably linked to consonant voicing, as they are reflexes of the same feature, can- not account for the full range of depressor effects. An Optimal Domains Theory account incorporating grounding con- straints to formalize tone–segment feature relations can. One problem these languages pose for single source theories is that some of the depressors are diachronically, as well as synchronically, voiceless. The Appendix establishes this point in detail for the Nguni group. Ó 2008 Elsevier Ltd. All rights reserved. Keywords: Depressor consonants; Voice-tone; Grounding constraints; Shona; Nguni; Proto-Bantu 1. Introduction It is common, cross-linguistically, for languages to phonologize the phonetic lowering effect voiced obstru- ents have on the pitch of a following vowel (Hombert, 1978; Hyman and Schuh, 1974). To account for this, theories in a variety of frameworks formalize an explicit link between laryngeal and tonal features. Single source theories consider [voice] and Low tone reflexes of the same feature, with one realization when associ- ated to a consonant and another when associated to a vowel (see e.g., Halle and Stevens, 1971; Harris, 1994; Halle, 1995; Bradshaw, 1999; Pearce, 2007). In contrast, multiple source approaches consider [voice] and Low tone distinct features, and phonetically grounded implicational constraints account for their interaction (see e.g., Khumalo, 1987; Peng, 1992; Hyman and Mathangwane, 1998; Mathangwane, 1999; Hansson, 2004; Hsieh and Kenstowicz, 2007). 0388-0001/$ - see front matter Ó 2008 Elsevier Ltd. All rights reserved. doi:10.1016/j.langsci.2008.12.015 q Earlier versions of this paper were presented at the Tone–Segment workshop in Amsterdam in June 2007 and at OCP5 at the University of Toulouse-Mirail. E-mail address: downing@zas.gwz-berlin.de Available online at www.sciencedirect.com Language Sciences 31 (2009) 179–198 www.elsevier.com/locate/langsci