Doctoral Dissertation Research: Phonetics of period doubling

University Of California-San Diego, La Jolla CA

Investigators

Abstract

The human voice is an essential part of speech, serving to identify and distinguish talkers. A fundamental question regarding human language is how voice quality affects speech production and perception. This project approaches the question by looking at “period doubling” in natural speech, where a voice has a rough quality and more than one pitch. This also frequently occurs in pathological voice and singing styles. This dissertation project provides insight into 1) the articulatory and acoustic properties of period doubling, compared to those of other voice qualities; 2) the interaction between perceived pitch and voice quality in period doubling; and 3) the role of period doubling in the perception of linguistic tone. The findings are relevant to theories of the voice in linguistics, speech-language pathology, and music. The study of voice quality improves our understanding of the differences between typical and disordered voices, which can be used by clinicians to improve diagnoses and therapy strategies for individuals with vocal pathology. A better understanding of the distribution of period doubling in typical speech is also important to improving pitch detection and voice synthesis technologies, which are used in text-to-speech and automatic speech recognition. The current project serves as a probe of how people produce and make use of voice quality when processing linguistic information. It consists of three studies. Study 1 includes a production experiment of different voice types in a tonal language to investigate the articulatory and acoustic properties of period doubling and its linguistic distribution. Study 2 investigates pitch and voice perception during period doubling using synthesized speech that is controlled for various acoustic properties. Study 3 investigates the role of period doubling and other voice qualities in tone identification, with the goal of explaining the interaction between pitch and voice in different voice types, and the roles they play in distinguishing words. This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.