1. MED-EL GmbH, Hannover, Germany
2. Department of Otolaryngology, Hannover Medical School, Hannover, Germany
3. Department of Otolaryngology, Goethe University Hospital Frankfurt, Frankfurt-am-Main, Germany
4. MED-EL GmbH, Würzburg, Germany
5. Department of Otolaryngology, Plastic and Aesthetic Surgery, Würzburg, Germany