1. UK Cochrane Centre; Summertown Pavilion 18 - 24 Middle Way Oxford UK
2. Faculty of Medicine, Khon Kaen University; Department of Otorhinolaryngology; Khon Kaen Thailand
3. Guy's Hospital; ENT Department; Gerat Maze Pond London UK SE1 9RT
4. Norwich Medical School, University of East Anglia; Department of Medicine; Norwich UK NR4 7TJ
5. Faculty of Brain Sciences, University College London; evidENT, Ear Institute; 330 Grays Inn Road London UK WC1X 8DA