1. Department of Clinical Neurophysiology Turku University Hospital and University of Turku Turku Finland
2. Department of Pediatrics and Adolescent Medicine Turku University Hospital and University of Turku Turku Finland
3. Department of Pediatrics The Hospital District of South Ostrobothnia Seinäjoki Finland
4. Department of Otorhinolaryngology Turku University Hospital Turku Finland
5. Department of Psychology and Speech and Language Pathology (Logopedics) Faculty of Medicine University of Helsinki Helsinki Finland
6. Department of Biostatistics Faculty of Medicine University of Turku Turku Finland