Impact of Clear, Loud, and Slow Speech on Scaled Intelligibility and Speech Severity in Parkinson's Disease and Multiple Sclerosis Purpose The perceptual consequences of rate reduction, increased vocal intensity, and clear speech were studied in speakers with multiple sclerosis (MS), Parkinson's disease (PD), and healthy controls. Method Seventy-eight speakers read sentences in habitual, clear, loud, and slow conditions. Sentences were equated for peak amplitude and mixed with multitalker ... Research Article
Research Article  |   June 01, 2014
Impact of Clear, Loud, and Slow Speech on Scaled Intelligibility and Speech Severity in Parkinson's Disease and Multiple Sclerosis
 
Author Affiliations & Notes
  • Kris Tjaden
    University at Buffalo, New York
  • Joan E. Sussman
    University at Buffalo, New York
  • Gregory E. Wilding
    University at Buffalo, New York
  • Disclosure: The authors have declared that no competing interests existed at the time of publication.
    Disclosure: The authors have declared that no competing interests existed at the time of publication.×
  • Correspondence to Kris Tjaden: tjaden@buffalo.edu
  • Editor: Jody Kreiman
    Editor: Jody Kreiman×
  • Associate Editor: Julie Liss
    Associate Editor: Julie Liss×
Article Information
Speech, Voice & Prosodic Disorders / Dysarthria / Hearing & Speech Perception / Acoustics / Special Populations / Speech, Voice & Prosody / Speech / Research Articles
Research Article   |   June 01, 2014
Impact of Clear, Loud, and Slow Speech on Scaled Intelligibility and Speech Severity in Parkinson's Disease and Multiple Sclerosis
Journal of Speech, Language, and Hearing Research, June 2014, Vol. 57, 779-792. doi:10.1044/2014_JSLHR-S-12-0372
History: Received November 19, 2012 , Revised April 1, 2013 , Accepted October 22, 2013
 
Journal of Speech, Language, and Hearing Research, June 2014, Vol. 57, 779-792. doi:10.1044/2014_JSLHR-S-12-0372
History: Received November 19, 2012; Revised April 1, 2013; Accepted October 22, 2013
Web of Science® Times Cited: 12

Purpose The perceptual consequences of rate reduction, increased vocal intensity, and clear speech were studied in speakers with multiple sclerosis (MS), Parkinson's disease (PD), and healthy controls.

Method Seventy-eight speakers read sentences in habitual, clear, loud, and slow conditions. Sentences were equated for peak amplitude and mixed with multitalker babble for presentation to listeners. Using a computerized visual analog scale, listeners judged intelligibility or speech severity as operationally defined in Sussman and Tjaden (2012) .

Results Loud and clear but not slow conditions improved intelligibility relative to the habitual condition. With the exception of the loud condition for the PD group, speech severity did not improve above habitual and was reduced relative to habitual in some instances. Intelligibility and speech severity were strongly related, but relationships for disordered speakers were weaker in clear and slow conditions versus habitual.

Conclusions Both clear and loud speech show promise for improving intelligibility and maintaining or improving speech severity in multitalker babble for speakers with mild dysarthria secondary to MS or PD, at least as these perceptual constructs were defined and measured in this study. Although scaled intelligibility and speech severity overlap, the metrics further appear to have some separate value in documenting treatment-related speech changes.

Acknowledgments
Portions of this study were presented at the Sixth Motor Control Conference, Groningen, the Netherlands, June 2011. Research supported by National Institute on Deafness and Other Communication Disorders grant R01 DC004689. We thank Jennifer Lam and Adrienne Ricchiazzi for assistance with manuscript preparation.
Order a Subscription
Pay Per View
Entire Journal of Speech, Language, and Hearing Research content & archive
24-hour access
This Article
24-hour access