Sentence intelligibility before and after voice treatment in speakers with idiopathic Parkinson's disease.
OBJECTIVE
The purpose of this study was to determine whether sentence intelligibility improves in speakers with idiopathic Parkinson's disease (PD) as a result of Lee Silverman Voice Treatment (LSVT). It was hypothesized that all the speakers would improve following treatment, in association with increased vocal loudness, which was the primary target of the treatment.


METHODS
Prospective study of eight Speakers with PD using a single-blinded, randomized pre-post treatment design, with multiple daily assessments before and after treatment was carried out. Resultant data were corrected for regression to the mean.


METHODS
Randomized digital recordings of sentences produced by speakers with idiopathic PD before and after the treatment were presented to normal-hearing listeners with equalized intensity at conversational loudness in the presence of pink noise. Percentage of words understood was calculated before and after the treatment. Changes in overall vocal intensity were also analyzed.


RESULTS
There was a statistically significant group effect from pre-to-post voice treatment; however, there was also significant interaction of treatment with speakers. Six of the speakers with PD improved significantly following voice treatment, one exhibited no change, and one exhibited a decline in sentence intelligibility post-treatment.


CONCLUSIONS
LSVT yielded significant improvement in sentence intelligibility for most speakers in the study but was not beneficial for two of the speakers despite the fact that they increased their overall vocal loudness.
School of Communication Sciences and Disorders, University of Memphis, 807 Jefferson Avenue, Memphis, TN 38105, USA. mcannito@memphis.edu
Michael P
MP
Cannito
Debra M
DM
Suiter
Doriann
D
Beverly
Lesya
L
Chorna
Teresa
T
Wolf
Ronald M
RM
Pfeiffer
D000368:Aged; D000369:Aged, 80 and over; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D010300:Parkinson Disease / Q000150:complications*; D011446:Prospective Studies; D013061:Speech Acoustics; D013065:Speech Intelligibility; D014832:Voice Disorders / Q000209:etiology / Q000628:therapy*; D014834:Voice Training