Hearing and acute otitis media in 13-year-old children.
Air and bone conduction thresholds of 330 unselected urban 13-year-old children with a known history of otitis were measured under ideal conditions, using standard clinical audiometry. In the subgroups of children with different numbers (0, 1-2, 3-7, > or = 8) of attacks of acute otitis media (AOM) in their history, the mean air conduction thresholds varied from 0.2 to 11.5 dB at different frequencies in different AOM subgroups. Air conduction pure tone averages (PTA, mean threshold at 0.5, 1 and 2 kHz) > 20 dB were not found in any of the ears. The mean bone conduction thresholds varied from -0.0 to 1.8 dB, depending on the subgroup and frequency (0.25 to 4.0 kHz) studied. Bone conduction PTAs > 10 dB were measured in 5 (0.8%) ears. Single bone conduction thresholds > 10 dB were found at different frequencies in 3 to 15 (0.5 to 2.3%) of the ears, and thresholds > 20 dB in only 2 ears (0.3%). The mean thresholds and number of ears with decreased hearing were distributed equally between different AOM subgroups, except that some air conduction high frequency losses were more frequent in children with > or = 8 attacks of AOM. We conclude that childhood AOM, even if it occurs frequently, seems not to have a significant harmful long-term effect on hearing.