Acoustic and linguistic interdependencies of irregular phonation

Abstract

Irregular phonation is a commonly occurring but only partially understood phenomenon of human speech production. We know properties of irregular phonation can be clues to a speaker's dialect and even identity. We also have evidence that irregular phonation is used as a signal of linguistic and acoustic intent. Nonetheless, there remain fundamental questions about the nature of irregular phonation and the interdependencies of irregular phonation with acoustic and linguistic speech characteristics, as well as the implications of this relationship for speech processing applications. In this thesis, we hypothesize that irregular phonation occurs naturally in situations with large amounts of change in pitch or power. We therefore focus on investigating parameters such as pitch variance and power variance as well as other measurable properties involving speech dynamics. In this work, we have investigated the frequency and structure of irregular phonation, the acoustic characteristics of the TIMIT Acoustic-Phonetic Speech Corpus, and relationships between these two groups. We show that characteristics of irregular phonation are positively correlated with several of our potential predictors including pitch and power variance. Finally, we demonstrate that these correlations lead to a model with the potential to predict the occurrence and properties of irregular phonation.