Ternary rhythm and the lapse constraint

Ternary rhythmic systems differ from binary systems in stressing every third syllable in a word, rather than every second. Ternary rhythm is well-established for only a small group of languages, including Chugach Alutiiq, Cayuvava, and Estonian, and possibly Winnebago. Nevertheless the stress patterns of these languages are sufficiently complex to warrant an on-going debate about the implications for metrical theory