1. Department of Otolaryngology, Head and Neck Surgery West Virginia University Morgantown West Virginia U.S.A.
2. Department of Otolaryngology, Head and Neck Surgery Massachusetts Eye and Ear Infirmary, Harvard Medical School Boston Massachusetts U.S.A.
3. Department of Speech, language and swallowing disorders Massachusetts General Hospital Boston Massachusetts U.S.A.
4. Department of Otolaryngology, Head and Neck Surgery Medical College of Wisconsin Milwaukee Wisconsin U.S.A.
5. Department of Otolaryngology Head and Neck Surgery Washington University in St Louis St Louis Missouri U.S.A.