Vocal Sound Pressure Level and Self-Perception of Speech and Voice in Men and Women with Idiopathic Parkinson Disease

This study compared vocal sound pressure level (SPL) and self-perception of speech and voice in men and women with idiopathic Parkinson disease (PD) and in healthy men and women. Thirty subjects with PD (15 men, 15 women) and 14 healthy comparison (HC) subjects (7 men, 7 women) participated in the study. They performed a variety of speech and voice tasks and carried out perceptual self-ratings of nine speech and voice characteristics. To assess performance stability, subjects repeated the data collection procedures on 3 different days. Results revealed that subjects with PD were statistically significantly lower in vocal SPL (2.0-4.0 dB SPL; 30 cm) during speech and voice tasks than HC subjects. Repeated measures across sessions revealed that subjects with PD were not significantly more unstable than HC subjects in their day-to-day performance for all variables examined. In addition, subjects with PD rated themselves as statistically significantly more severely impaired than HC subjects on all nine self-rated perceptual variables examined. These data provide additional descriptive information on speech and voice characteristics in people with PD and may be useful in assessment and treatment planning for this population.