1. U.O.C. di O.R.L., San Gennaro Hospital, ASL Nal, Naples
2. Department of Pediatrics, Second University of Naples, Naples
3. U.O.C. di O.R.L., Azienda Ospedaliera Pediatrica Santobono Pausilipon, Naples
4. Department of Pediatrics, IRCCS San Matteo-University of Pavia, Pavia
5. Servizio di Foniatria ed Audiologia, Second University of Naples, Naples, Italy