Gates, Jennifer
(2020)
The Ability of Persons with Parkinson's Disease to Manipulate Vocal Intensity and Articulatory Precision in an Intra-Operative Setting.
Master's Thesis, University of Pittsburgh.
(Unpublished)
Abstract
Parkinson’s disease is a degenerative neurological disease associated with decreased basal ganglia control circuit output, leading to decreased facilitation of cortical motor areas and subsequent motor impairments (Wichmann & DeLong, 1996). Motor impairments, including rigidity, bradykinesia, reduced range of motion and difficulty initiating movement, impact both respiratory function and speech in persons with Parkinson’s disease (PWPD), often leading to hypophonia and hypokinetic dysarthria (Darling & Huber, 2011). Hypokinetic dysarthria includes, among other characteristics, reduced loudness and imprecise articulation, and therefore reduced speech clarity.
The purpose of this study was to determine if PWPD were able to manipulate speech intensity and articulatory precision in soft versus loud stimulus presentation conditions in an intra-operative environment. Articulatory precision was measured using the F2 ratio, based on the second formant values of the vowels /i/ and /u/ (Sapir, 2007). As /i/ is produced anteriorly in the oral cavity and /u/ is produced posteriorly, an increase in this ratio is anticipated to accompany greater articulatory precision. It was hypothesized that PWPD would be able to increase vocal intensity, which would result in larger F2 ratios.
Participants consisted of 16 PWPD undergoing surgery for deep brain stimulation and simultaneous recording in the subthalamic nucleus and cortex. Participants repeated CVCVCV utterances presented auditorily at soft and loud levels. Acoustic signals were recorded and average vowel intensities and second formant values for /i/ and /u/ productions within each utterance were extracted. Second formant values were then used to calculate the F2 ratio for each utterance.
Wilcoxon Signed-Rank Tests revealed that, while intensity significantly increased in the loud compared to the soft condition, the F2 ratio did not demonstrate this increase. Of particular interest, examination of individual participants revealed that 3 patients did not increase intensity in the loud stimulus condition. When only participants who increased intensity were included in subsequent analyses, the F2 ratio did demonstrate a significant increase in the loud stimulus condition.
The current study demonstrates that, even with methodological differences as a result of the intra-operative environment, when patients are able to increase speech intensity, they also increase articulatory precision.
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Item Type: |
University of Pittsburgh ETD
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Status: |
Unpublished |
Creators/Authors: |
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ETD Committee: |
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Date: |
19 June 2020 |
Date Type: |
Publication |
Defense Date: |
20 March 2020 |
Approval Date: |
19 June 2020 |
Submission Date: |
23 April 2020 |
Access Restriction: |
No restriction; Release the ETD for access worldwide immediately. |
Number of Pages: |
45 |
Institution: |
University of Pittsburgh |
Schools and Programs: |
School of Health and Rehabilitation Sciences > Communication Science and Disorders |
Degree: |
MS - Master of Science |
Thesis Type: |
Master's Thesis |
Refereed: |
Yes |
Uncontrolled Keywords: |
loudness, intensity, vocal intensity, intensity manipulation, articulatory precision, articulatory precision manipulation, F2ratio, Parkinson's disease, LSVT |
Date Deposited: |
19 Jun 2020 13:19 |
Last Modified: |
19 Jun 2020 13:19 |
URI: |
http://d-scholarship.pitt.edu/id/eprint/38776 |
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