1. Rehabilitation Foundation, Helsinki, Finland
2. Department of Psychology and Logopedics, Faculty of Medicine, University of Helsinki, Helsinki, Finland
3. Department of Logopedics, Philosophical Faculty, School of Humanities, University of Eastern Finland, Joensuu, Finland
4. Department of Otorhinolaryngology and Phoniatrics, Head and Neck Surgery, Helsinki University Hospital, University of Helsinki, Helsinki, Finland