1. Department of Electrical Engineering, Chalmers University of Technology, Gothenburg, Sweden;
2. Department of Audiology, Sahlgrenska Academy, University of Gothenburg, Gothenburg, Sweden;
3. Department of Clinical Science, Intervention and Technology, Karolinska Institute, Stockholm, Sweden;
4. Department of Otolaryngology, Head and Neck Surgery, Sahlgrenska Academy, University of Gothenburg, Gothenburg, Sweden