[1] Privolzhsky Res Med Univ, Dept Ear Nose & Throat, 10-1 Minin & Pozharsky Sq, Nizhnii Novgorod 603005, Russia
[2] Privolzhsky Res Med Univ, Dept Hosp Pediat, 10-1 Minin & Pozharsky Sq, Nizhnii Novgorod 603005, Russia
[3] Peoples Friendship Univ Russia RUDN Univ, Dept Pediat, 6 Miklukho Maklaya St, Moscow 117198, Russia
[4] Kazan Fed Univ, Res Lab Clin Linguist, 18 Kremlyovskaya St, Kazan 420008, Republic Of Tat, Russia