1. Department of Speech and Hearing Sciences, The George Washington University, Washington, DC, USA
2. Language Section, Voice, Speech and Language Branch, National Institute on Deafness and Other Communication Disorders, National Institutes of Health, Bethesda, MD, USA
3. Fischell Department of Bioengineering, University of Maryland, College Park, MD, USA
4. Voice Treatment Center, Medical Faculty Associates, The George Washington University Medical Center, Washington, DC, USA
5. Department of Epidemiology, Johns Hopkins Bloomberg School of Public Health, Baltimore, MD, USA
6. University of Kansas Medical Center, Kansas City, KS, USA
7. Department of Neurological Sciences, Rush University Medical Center, Chicago, IL, USA