1. Department of Ear, Nose and Throat, Head and Neck Surgery, Ålesund Hospital, Aalesund, Norway,
2. Department of Neuroscience, Norwegian University of Science and Technology, Trondheim, Norway,
3. Department of Public Health and Nursing, Norwegian University of Science and Technology, Trondheim, Norway,
4. Department of Psychology, University of Oslo, Oslo, Norway,
5. Department of Ear, Nose and Throat, Head and Neck Surgery, Haukeland University Hospital, Bergen, Norway,
6. Department of Health and Social Science, Norwegian University of Science and Technology, Trondheim, Norway, and
7. Department of Ear, Nose and Throat, Head and Neck Surgery, St. Olavs University Hospital, Trondheim, Norway