1. the Department of Otolaryngology-Head and Neck Surgery, Hospital for Sick Children, University of Toronto, Toronto, Ontario, Canada.
2. the Department of Communication Disorders, Hospital for Sick Children, University of Toronto, Toronto, Ontario, Canada.
3. the Centre for Paediatric Voice and Laryngeal Function, Hospital for Sick Children, University of Toronto, Toronto, Ontario, Canada.
4. the Division of Infectious Diseases, Hospital for Sick Children, University of Toronto, Toronto, Ontario, Canada.