Date of Award

Spring 1-1-2011

Document Type


Degree Name

Master of Arts (MA)


Speech, Language & Hearing Sciences

First Advisor

Elizabeth V. Boyd

Second Advisor

Lorianne O. Ramig

Third Advisor

Neeraja Sadagopan


Idiopathic Parkinson Disease (PD) is a neurodegenerative movement disorder that affects an estimated 1 in 1000 people worldwide. The associated speech disorder is characterized by reduced movement in the speech mechanism and reduced loudness. Lee Silverman Voice Treatment (LSVT® LOUD) has been shown to be an effective therapy for treating parkinsonian voice. In recent years, a surgical intervention--deep brain stimulation of the subthalamic nucleus (STN-DBS)--has been used to treat the movement symptoms associated with PD. It has been suggested that this procedure changes the characteristics of the voice and speech. The precise effect that STN-DBS has on speech is still being studied. This study uses acoustic analysis to compare the speech of subjects with PD with subjects with PD who have undergone STN-DBS. It addresses the following questions: 1) Compared to PD subjects, do PD subjects who have bilateral STN-DBS improve after LSVT? 2) Do two additional weeks of treatment affect the outcome? And 3) does the nature of the additional treatment (traditional LSVT LOUD vs. LSVT LOUD/CLEAR) affect treatment outcome? Six people (1 female, 5 males) with PD and bilateral STN-DBS made up the experimental group. The control group was part of a larger study of people with PD conducted by the same research group. Euclidean distances of the difference in formant frequencies, and vowel duration between F2 /i/ and F2 /I/ were compared pre- and post-LSVT, and after two additional weeks of therapy. The subjects were divided into two groups of three for the two additional weeks, one group receiving two extra weeks of traditional LSVT LOUD and the other group receiving an experimental articulation treatment called LSVT LOUD/CLEAR. Results found no significant differences pre-post, after two additional weeks (6 week), or across treatment groups. Clinical implications and limitations are discussed.