1. Department of Otorhinolaryngology, Faculty of Medicine, Universidad de Chile, Santiago de Chile, Chile
2. Hospital Clínico Universidad de Chile, Santiago, Chile
3. Department of Otorhinolaryngology, Pontificia Universidad Católica de Chile, Santiago, Chile
4. Department of Speech and Hearing Sciences, Faculty of Medicine, Universidad de Chile, Santiago de Chile, Chile
5. School of Speech and Hearing Sciences, Universidad de los Andes, Santiago de Chile, Chile
6. Departamento de Tecnología Médica, Facultad de Medicina, Universidad de Chile, Santiago de Chile, Chile
7. International Centre for Evidence in Disability, London School of Hygiene & Tropical Medicine, Keppel St, United Kingdom