I'm looking for some research data for the amount of hearing loss resulting from otitis media with effusion (OME), or glue ear, or fluid in the middle ear. The typical answer I read is "20-30dB" but this result is never referenced. Median/average, 90 percentile, kind of data would be very useful.
Otitis media with effusion (OME) is most common in young children (under 2) making studying the effects on hearing difficult. While newborn hearing screening is common, it does not provide a full audiogram. Collecting an audiogram a a child who does not speak or understand direction and has limited attention is hard. Collecting an audiogram on a sick child is even harder. With a some serious caveat regarding sample size, Werner and Ward (1997) provide the best study on this that I am aware of. They conclude that the effect of OME is 15-30 dB (while the child is sick).