1. Faculty of Business Management and Social Sciences, Section of Speech and Language Therapy, University of Applied Sciences, Osnabrueck, Germany
2. SRH Technical College for Speech and Language Therapy, Bonn, Germany
3. Department of Otorhinolaryngology, Section of Phoniatrics and Pedaudiology, University of Ulm, Germany
4. Faculty of Social Work and Health, HAWK University of Applied Sciences and Arts, Hildesheim, Germany