1. Clinic and Polyclinic for Otolaryngology University Medical Center Hamburg‐Eppendorf Hamburg Germany
2. Institute of Medical Technology Hamburg University of Technology Hamburg Germany
3. Department of Otorhinolaryngology/Head and Neck Surgery University of Bonn Bonn Germany
4. Department of Otorhinolaryngology Klinikum Braunschweig Braunschweig Germany
5. Department of Otorhinolaryngology, Head and Neck Surgery Evangelisches Krankenhaus, Carl von Ossietzky‐University Oldenburg Germany