1. ENT Division, Novara Maggiore Hospital, 28100 Novara, Italy
2. CENTAI Institute, 10138 Turin, Italy
3. Departament de Fisica, Universitat Politecnica de Catalunya, Campus Nord, 08034 Barcelona, Spain
4. Department of Otorhinolaryngology, Ss. Trinità Hospital, 28021 Borgomanero, Italy
5. ENT Division, Health Science Department, School of Medicine, Universitá del Piemonte Orientale, 28100 Novara, Italy