Electronic Theses and Dissertations

Identifier

3740

Author

Kristin Percy

Date

2016

Date of Award

7-21-2016

Document Type

Thesis

Degree Name

Master of Arts

Major

Speech Language Pathology

Committee Chair

Eugene Buder

Committee Member

Naomi Eichorn

Abstract

LSVT-LOUD® has been shown to improve phonatory quality in patients with PD. Previous studies have shown an increase in vowel space area following treatment, but questions remain regarding possible methodological issues in interaction with phonatory factors. This study addresses these questions by comparing multiple formant measurment methods and vowel space metrics. Ten participants were recorded on two separate days before and after treatment. Formants were measured using a human-guided reference (dubbed 'HGIM'), LPC, and two forms of cepstrally-liftered spectrum. Multiple vowel space metrics including the vowel articulation index, F2i/F2u, area of the vowel quadrilateral, and vowel formant dispersion utilized both lax and corner vowels to explore vowel space changes. Analysis revealed no significant change in vowel space following LSVT. High variability in LPC with a fixed coefficient was noted. These results do not support previous claims of increased vowel space but suggest that formant measurement methods may influence results.

Comments

Data is provided by the student.

Library Comment

dissertation or thesis originally submitted to the local University of Memphis Electronic Theses & dissertation (ETD) Repository.

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