This study is designed to check the effect of the use of the ear popper device on serous otitis media in children and on the conductive hearing loss accompanying the otitis. It is intended that 30 children aged 3-18 years will participate in the study. The inclusion criteria are : clinical serous otitis media for a duration of more then 3 months, a conductive hearing loss of at least 15 decibels air bone gap and tympanometry type B or C. The children will use the ear popper for 7 weeks. They will undergo otologic examination, audiometry and tympanometry at the beginning ao the trial, at 7 weeks and at 3 months from the beginning of the trial. The otologic findings and the audiometry and tympanometry results before and after the trial will be compared. We will try to determine whether the use of the ear popper in the test group will improve the conductive hearing loss and prevent the need for tympanostomy tube insertion.