1. Department of Otolaryngology/Head and Neck Surgery, Haukeland University Hospital, Bergen, Norway
2. Department of Clinical Medicine, Faculty of Medicine and Dentistry, University of Bergen, Bergen, Norway
3. Faculty of Health and Social Sciences, Bergen University College, Bergen, Norway
4. Department of Clinical Science, Section of Logopedics, Phoniatrics and Audiology, Lund University, Lund, Sweden