The 4th International Symposium on Tonal Aspects of Languages
Nijmegen, The Netherlands
This paper reports on the interaction between Fundamental Frequency (F0), voicing and aspiration in Tsua, a Central Khoisan click language spoken in Botswana. Tsua lacks the tonal mobility of spreading and shifting found in many neighboring Bantu languages. Nevertheless, original field research in 2012 and 2013 revealed that Tsua has an extreme tonal depressor effect that lowers a post-consonantal, rootinitial H-tones production by ~50 Hz or more. Tonal depression can be triggered by voiced stops, aspirated stops or the glottal fricative /h/, an effect that has been missed by the small amount of previous research on Tsua. However, this inquiry also found that 19.2% of the root-initial H-tones that are expected to be depressed by the triggering environment are produced without depression, perhaps providing a reason as to why the effect has been overlooked. Cognates with the Central Khoisan languages G|ui and Kua were investigated to formulate a plausible explanation. It was determined that tonal depression exceptions with root-initial voiced stops in Tsua always correspond with G|ui and Kua cognates that have rootinitial nasals or nasalized clicks, consonants which do not trigger depression in Tsua. These results provide insight into diachronic sound change that has influenced the production of Tsua lexical tone.
Index Terms: tone, production, depressors, consonant-tone interaction, Khoisan
Bibliographic reference. Mathes, Timothy K. (2014): "extreme tonal depressor effects in Khoisan: evidence from Tsua", In TAL-2014, 1-5.