1. Cleveland, Ohio, Bethesda and Baltimore, Maryland, London, England, Philadelphia, Pennsylvania, and Maywood, Illinois
2. Cleveland Clinic Health Sciences Center, Ohio State University, and Caritas Saint Vincent Charity Hospital.
3. WG Magnuson Clinical Center, and the Department of Rehabilitation Medicine, National Institutes of Health.
4. Royal National Throat, Nose & Ear Hospital and the University of London.
5. Lewisham University Hospital, Lewisham NHS Trust.
6. Thomas Jefferson University and the Department of Otolaryngology-Head and Neck Surgery, The Graduate Hospital, Philadelphia.
7. Department of Otolaryngology-Head and Neck Surgery, Loyola University Chicago.
8. Johns Hopkins Medical Institutions and Department of Otolaryngology-Head and Neck Surgery, Greater Baltimore Medical Center.