1. Duke Voice Care Center, Division of Otolaryngology–Head & Neck Surgery, Duke University Medical Center, Durham, North Carolina, USA
2. Voice and Swallowing Institute, Department of Otolaryngology–Head & Neck Surgery, New York Eye and Ear Infirmary, New York, New York, USA
3. Department of Otolaryngology–Head & Neck Surgery, Boston Medical Center, Boston University School of Medicine, Boston, Massachusetts, USA
4. UCSF Voice Center, Department of Otolaryngology–Head & Neck Surgery, University of California–San Francisco, San Francisco, California, USA