Phonological pitch

Abstract

The theory proposed in this thesis, Phonological Pitch, concerns the representation and behavior of the tone feature. It is a formally simple phonological theory constrained by a set of explicit extragrammatical principles. Phonological Pitch contains two major grammatical mechanisms. First, tone is represented with a single multivalued feature (Pitch) whose value can range from 1 to n, where n is a language-specific number with no universal upper limit. Second, the Contiguity Hypothesis states that tone groups in rules must always form contiguous sets, though these groups can vary from rule to rule. Phonological Pitch can be so simple because the power of the grammatical theory is constrained with independently necessary extragrammatical factors. Specifically, limits on the number of tone levels arise from learnability and perceptual constraints, which can be precisely formalized, that also play a role in nonlinguistic domains. Similarly, the Contiguity Hypothesis is derived from psychoacoustic constraints on discriminating between acoustically similar pitches. Other perceptual and physiological constraints explain patterns in the typology of contour tones and in the interactions of tone with other features. The empirical support for Phonological Pitch includes the following. First, languages are attested with as many as five distinct tone levels, and the number of languages with n tone levels gradually decreases as n increases, rather than dropping off abruptly at some point. An analysis using learnability and perceptual constraints can explain this gradual drop better than a universal grammatical upper limit. Second, tone rules can transpose sets of tones up or down by a fixed interval, a fact which is easier to formalize with a single multivalued feature than with a set of binary features. Third, tone groups do not form universal natural classes nor groups with noncontiguous tones, as other tone theories predict. Fourth, tone interacts not only with laryngeal features like voicing, but also with nonlaryngeal features like vowel height, and both the existence and relative rarity of tone-vowel height interactions imply that understanding tone interactions requires reference to extragrammatical physiological factors.