Vowel duration and neutralization of vowel length contrasts in Kinyarwanda

Abstract

In Kinyarwanda, a Bantu language spoken in Rwanda, there is a contrast in vowel length, as in [ɡutaka] “to scream” and [ɡutaːka] “to decorate”. This contrast is neutralized in various positions: there are only short vowels word-initially or -finally, and there are only long vowels before a nasal-obstruent (NC) sequence or after a consonant-glide (CG) sequence. An acoustic study was performed to determine how vowel duration varied according to (a) vowel type (short, long, pre-NC, post-CG), (b) vowel height (low, high), (c) position in the word (initial, penultimate, final), and (d) position in the phrase (initial word, final word). It was found that pre-NC vowels were intermediate in duration between short vowels on the one hand and long or post-CG vowels on the other. Low vowels were longer than high vowels. Word-penultimate vowels were longer than word-initial or -final vowels, and phrase-penultimate vowels were longer than other word-penultimate vowels. The duration of phrase-final vowels depended on the extent of final devoicing. Implications for the representation and implementation of the vowel length contrast are discussed.