1. Department of ENT/Head and Neck Surgery, Maastricht University Medical Center, MHeNS School for Mental Health and Neuroscience, Maastricht, The Netherlands,
2. Department of Methodology and Statistics, Maastricht University, CAPHRI School for Public Health and Primary Care, Maastricht, The Netherlands, and
3. Institute of Mechatronics, University of Innsbruck, Innsbruck, Austria