1. UChicago Voice Center, Department of Surgery, Section of Otolaryngology–Head & Neck Surgery University of Chicago Chicago Illinois U.S.A.
2. Keck School of Medicine of University of Southern California Los Angeles California U.S.A.
3. USF Health Voice Center, Department of Otolaryngology–Head & Neck Surgery University of Southern Florida Tampa Florida U.S.A.
4. Division of Laryngology, Department of Otolaryngology–Head & Neck Surgery University of Washington School of Medicine Seattle Washington U.S.A.
5. USC Voice Center, Department of Otolaryngology–Head & Neck Surgery University of Southern California Los Angeles California U.S.A.
6. Department of Otolaryngology–Head & Neck Surgery Georgetown University Medical Center Washington DC U.S.A.