[1] Cardiff Univ, Sch Med, Dept Psychol Med & Neurol, Cardiff, S Glam, Wales
[2] Univ Tampere, Sch Med, Dept Otorhinolaryngol, FIN-33101 Tampere, Finland
[3] Nagoya Univ, Grad Sch Med, Dept Otorhinolaryngol, Nagoya, Aichi 4648601, Japan
[4] Univ Helsinki Hosp, Dept Otolaryngol, Helsinki, Finland
[5] Satakunta Univ Appl Sci, Fac Technol & Maritime Management, Pori, Finland
[6] Childrens Hosp, Dept Otolaryngol, Boston, MA 02115 USA
[7] Harvard Univ, Sch Med, Boston, MA USA