POST-NASAL DEVOICING IN TSWANA
Andries W. Coetzee, Susan Lin & Rigardt Pretorius
ICPhS XVI. p. 861-864

Tswana is traditionally described as having a process of post-nasal devoicing (/mba/ > [mpa]). If this is accurate, then Tswana poses a challenge to views that neutralization processes should be articulatorily grounded. Airflow leakage through the nasal cavity should promote, not inhibit, voicing post-nasally. Zsiga et al. performed acoustic analysis of the speech of 6 Tswana speakers, and found no evidence of post-nasal devoicing. They conclude that, counter to traditional descriptions, Tswana does not have post-nasal devoicing. In an independent study, we collected speech from 12 Tswana speakers. Four of our speakers showed clear and consistent post-nasal devoicing. In this paper, we present the data for these 4 speakers to show that at least some speakers of Tswana do have an active process of postnasal devoicing. We also consider possible explanations for this process, arguing that it is motivated by perceptual rather than articulatory considerations.

Full paper

Solé, M. J., Beddor, P. S., Ohala, M. Eds. (2007) Experimental Approaches
to Phonology. Oxford University Press.

Table of contents

From the publisher:
This wide-ranging survey of experimental methods in phonetics and phonology shows the insights and results provided by different methods of investigation, including laboratory-based, statistical, psycholinguistic, computational-modeling, corpus, and field techniques. The five chapters in the first part of the book examine the recent history and interrelations of theory and method. The remaining 18 chapters are organized into parts devoted to four key current areas of research: phonological universals; phonetic variation and phonological change; maintaining, enhancing, and modeling phonological contrasts; and phonological knowledge. The book provides fresh insights into the findings and theoretical advances that emerge from experimental investigation of phonological structure and phonological knowledge, as well as critical perspectives on experimental methods in the perception, production, and modeling of speech.