A comparison of lip positions for /ɨ/ and /Ɯ/ in Bora

Abstract

Bora is a Witotoan language spoken by about 750 persons in the Amazon jungle of Peru and 100 in Colombia. Its phonemic vowels are /i e a o ɨ Ɯ/ (Thiesen and Weber 2012). A contrast between a central and a back vowel which are otherwise identical is theoretically significant since it shows that a binary feature [ + /-back] is too weak to encode all phonological contrasts along the front/back dimension. The three high vowels of Bora have been acoustically confirmed with measurements of F1-F3 (Parker 2001), but there has been no articulatory investigation of these vowels. Impressionistically all of the Bora vowels except /o/ are articulated with unrounded lips. However, Ladefoged and Maddieson (1996) note that high back unrounded vowels in languages such as Japanese involve a gesture of lip compression or inrounding. Consequently, an important research question is whether the distinction between /ɨ/ and /Ɯ/ in Bora can be relegated to a difference in lip positions rather than to a primary contrast in tongue backness? To test this hypothesis, we obtained video recordings of native speakers on location in a Bora village (6 males and 7 females), and we report lip position data from these recordings.