1. Department of Otolaryngology–Head and Neck Surgery University of Cincinnati College of Medicine Cincinnati Ohio U.S.A.
2. Division of Speech–Language Pathology Cincinnati Children's Hospital Medical Center Cincinnati Ohio U.S.A.
3. Department of Speech Pathology and Audiology Miami University Oxford Ohio U.S.A.
4. Head and Neck Regenerative Medicine Laboratory, Mayo Clinic Arizona, Division of Pediatric Otolaryngology Phoenix Children's Hospital Phoenix Arizona U.S.A.
5. Professional Voice Center of Greater Cincinnati Cincinnati Ohio U.S.A.
6. Cincinnati Boychoir Cincinnati Ohio U.S.A.
7. Cathedral Choral Society Washington National Cathedral Washington District of Columbia U.S.A.
8. Division of Biostatistics and Epidemiology Cincinnati Children's Hospital Medical Center Cincinnati Ohio U.S.A.
9. Division of Pediatric Otolaryngology Cincinnati Children's Hospital Medical Center Cincinnati Ohio U.S.A.