Title: The synchronic and diachronic phonology of ejectives
Description: Although ejectives are the fourth most common type of stop and are found in 18% of the languages of the world, their phonological patterning has never been explored in depth. Based on a sample of over 180 dialects from genetically diverse languages, this thesis presents a typology of the major phonological processes involving ejectives, using the feature geometry of Clements and Hume (1995) and the phonological operations of spreading and delinking.

Spread of the Laryngeal node specified for (constricted glottis) is shown to account for ejective assimilation. A Laryngeal Markedness Statement formalizes the asymmetric spreading behavior of (voice) and (c.g.).

It is proposed that most ejective lenition processes may be formalized as the delinking of various feature geometric structures. Delinking of the Laryngeal node or of the feature (c.g.) results in deglottalization. Delinking of other structures often yields debuccalization. There are four parameters in Universal Grammar for debuccalization: delinking of the Root node, the Oral Cavity Node, C-place, and individual place features. Evidence is provided for all but C-place delinking, which depends on various theoretical assumptions. Data from Individual Place Feature Delinking demonstrates the independence of primary and secondary articulations, since primary place may debuccalize but leave secondary articulation under Vocalic intact. Dissimilation is also viewed as delinking.

The voicing of ejectives is phonologically straightforward, and is shown to result from the spread of (voice), or from delinking with fill-in of (voice) as default. Historical linguists, however, have criticized this change in the Glottalic Theory of Proto-Indo-European, which reconstructs ejectives in PIE, and requires the change of ejective to voice in daughter languages. Synchronic and diachronic examples are presented which support this contested aspect of the Glottalic Theory.

Evidence is provided that the creation of ejectives through fusion with an obstruent and glottal stop requires the admission of fusion as a basic phonological operation. The converse change of fission of an ejective into a sequence of plosive plus glottal stop is much rarer.

This study deepens the empirical understanding of ejectives and contributes to both phonological theory and to typologies of sound change.