1. Division of Otolaryngology University of Montreal Montreal Canada
2. Department of Physical Medicine and Rehabilitation University of Pittsburgh School of Medicine Pittsburgh Pennsylvania U.S.A.
3. UPMC Voice Center, Department of Otolaryngology University of Pittsburgh School of Medicine Pittsburgh Pennsylvania U.S.A.
4. UCSF Voice and Swallowing Center, Division of Laryngology, Department of Otolaryngology – Head and Neck Surgery University of California, San Francisco School of Medicine San Francisco California U.S.A.