Recent findings from studies of populations of children with and without otitis media show that a poor ability to equalize negative pressure is a fundamental deficit of eustachian tube function. Not only was active function found to be poor in children with otitis media with effusion, it was also impaired in healthy children, as compared to adults. However, the deficit improved with age and time. The active rather than the passive tubal function seems to be of critical importance with respect to proneness to recurrent acute otitis media and secretory otitis media. This suggests the involvement of primarily a eustachian tube opening dysfunction or muscular opening hypofunction in children, which is considered to be a primary endogenous etiologic factor. In a subgroup of children with recurrent acute otitis media or secretory otitis media, habitual sniffing in combination with closing failure and poor active function may be a possible mechanism for the development of otitis media.