Onsets and syllable prominence in Umutina

In Umutina the distribution of main word stress is sensitive to the sonority degree of vowels within a two-syllable window at the right side of the word, a property which it shares with a number of other languages. What makes Umutina particularly interesting is the fact that low sonorant onsets in the word final syllable impede the retraction of stress to the prefinal syllable, even when the prefinal nucleus is more sonorant than the final one. A constraint analysis is proposed based on the hypothesis that what makes syllables with low sonorant onsets prominent is the sharp sonority rise between a low sonorant onset and the following nucleus.