1. Glasgow Royal Infirmary; MRC Institute of Hearing Research (Scottish Section); Queen Elizabeth Building 16 Alexandra Parade Glasgow UK G31 2ER
2. University Medical Center Utrecht; Department of Otorhinolaryngology & Julius Center for Health Sciences and Primary Care; PO Box 85500 Utrecht Netherlands 3508 AB
3. University of Southampton School of Medicine; Department of Community Clinical Sciences; Aldermoor Health Centre Aldermoor Close Southampton UK SO16 5ST
4. Syddansk Universitetscenter; Institut for Sundhedstjenesteforskning; Campusvej 55 Odense M Denmark 5230
5. Oxford Radcliffe Hospitals NHS Trust; Department of Otolaryngology - Head and Neck Surgery; Level LG1, West Wing John Radcliffe Hospital Oxford UK OX3 9DU