1. Department of Otorhinolaryngology, Head and Neck Surgery, Maastricht University Medical Center, P.O. Box 5800, 6202 AZ Maastricht, The Netherlands
2. Department of Speech and Language Pathology, HAN University of Applied Sciences, 6525 EN Nijmegen, The Netherlands
3. Department of Methodology and Statistics, Maastricht University, 6229 HA Maastricht, The Netherlands
4. Department of Neurology, Maastricht University Medical Center, 6202 AZ Maastricht, The Netherlands
5. Departamento de Cirugía, Hospital de Mataróy CIBEREHD, Instituto de Salud Carlos III, Mataró, Spain