1. Duke Voice Care Center, Division of Otolaryngology-Head & Neck Surgery, Duke University Medical Center; Durham North Carolina
2. Department of Biostatistics and Bioinformatics; Duke University Medical Center; Durham North Carolina
3. Department of Communication Sciences and Disorders, Division of Otolaryngology-Head & Neck Surgery (Adjunct); University of Utah; Salt Lake City Utah
4. Lions Voice Clinic, Department of Otolaryngology/Head and Neck Surgery; University of Minnesota; Minneapolis Minnesota U.S.A.