1. Department of Otorhinolaryngology; SRH Wald-Klinikum Gera; Gera Germany
2. Department of Otorhinolaryngology; University of Wuerzburg; Wuerzburg Germany
3. Department of Otorhinolaryngology; Innsbruck University Hospital; Innsbruck Austria
4. Division of Phoniatrics; ENT University Hospital Graz, Medical University Graz; Graz Austria
5. Department of Audiology and Phoniatrics; Charité-Medical University of Berlin; Berlin Germany