Reanalyzing Thai glottal codas: probability, perception, and displaced contrast

The distribution of glottal stop codas in Thai is largely predictable, suggesting that they ought to be absent from lexical representations. However, tonal patterns and a handful of exceptional forms seem to require that they be present. This paper proposes a novel approach to this well-known problem, namely, that glottal codas are neither fully absent nor fully present: word-final glottal codas may be underlyingly present, but those in other environments are inserted. A motivation for this epenthesis is suggested by an analysis of the phonetic duration and textual frequency of various syllable types, which indicates that the perceptual reliability of the vowel length contrast would likely be seriously compromised in stressed, open syllables. The glottal coda of a CV? syllable may thus act as a displaced contrast marker for the preceding vowel's shortness.